Composting method

Abstract

Disclosed is a method for composting organic material for the production of a biofertilizer having a desired content of one or more selected nutrients. It is a key feature of the invention that the organic material is hygienizated / sanitized during the process whereby the number of harmful seeds and microorganisms are reduced or virtually eliminated.

Description

[0001] Composting Method

[0002] The present invention relates to organic fertilizer, more specifically to a method for making organic fertilizer having a desired content of nutrients such as N, P and K. The method also comprises hygienization, preventing spreading of infectious agents.

[0003] Technical Background

[0004] Recycling nutrients in biomass residues as fertilizer and soil improver is pivotal for a more sustainable plant production. At present, various European waste resources including household waste and sludge are largely being incinerated. In this way, the energy content of the organic material is used. However, certain nutrients such as N are lost, and the availability of e.g., P is reduced in the ashes after combustion. In the third world and partly in Europe, garbage is deposited in landfills which potentially causes environmental problems and, moreover, the nutrients are not recycled to new plant production. Only a minor part, mainly manure, is recirculated after biogas production where a proportion of the energy is reused, and the degassed slurry is returned to agricultural land for reuse of nutrients.

[0005] Without recycling of nutrients in waste, chemical fertilizers must be used. The advantage of chemical fertilizers is a high nutrient concentration and plant availability of the nutrients and lower transport costs. The disadvantages include high energy consumption and high price.

[0006] Hygienization effect of composting: It is well documented that the heat generated during the thermophilic phase of the composting process can inactivate the great majority of potential risk organisms such as human, animal or plant pathogens as well as weed seeds. Hence, proper composting is expected to inactivate human pathogenic bacteria such as E. coli and Salmonella spp. (Termorshuizen & Alsanius, 2016). Hence, both E. coli and Salmonella spp. are expected to be eliminated by exposure to 55°C for one hour or 65°C for 15-20 minutes (Jones & Martin, 2003). Reduction in ammonia and CO2 emissions from composting: The effect of biological air cleaning has previously been demonstrated by (Domino 2006) and (BACESS 2006).

[0007] Fertilizer effect of N and P in compost: Initial experiments with composted degassed fibers from a biogas plant were performed at 0kologihaven with the herb species dill, parsley, coriander and basil. The results indicated that this product was suitable as a biofertilizer which gave growth comparable to a standard fertilizer when applied at a dose of 10% (by volume) in mixture with 90% sphagnum peat. (Dalsgaard, M. 2020)

[0008] Plant availability of P after co-composting: Mixing of wood ash into organic waste prior to composting is known to improve compost quality and may reduce the amount of compost required to raise pH to suitable levels, e.g., in poor tropical soils (Bougnum et al., 2011). The effect on P availability in ash after co-composting has not been clearly documented.

[0009] Plant availability of P in compost and other organic fertilizers can be evaluated by chemical extraction with various solvents and is often expressed as percentage of total P in the fertilizer (Brod et al., 2015; Christiansen et al., 2018). The extraction can be done with solvents with different 'extraction strengths', hence extraction with nitric acid corresponds to total P whereas extraction with ammonium citrate corresponds to a moderate P extraction and water extraction corresponding to a relatively weak P extraction. Citrate extractable P and water extractable P can be recalculated as percentage of total P and may serve as an indicator of plant available P.

[0010] Protection against fungal plant diseases: Research on American universities have demonstrated the ability of compost to combat fungal plant diseases such as Pythium root rot and Phytophthora root rot (US EPA, 1997). Australian research has also demonstrated that compost can suppress wilt caused by Fusarium spp., damping off caused by Fusarium, Pythium, Rhizoctonia and Sclerotium spp. As well as stem and root rot caused by Fusarium, Rhizoctonia, Pythium, Sclerotium and Aphanomyces spp. (Compost for soils, 2009). The scientific literature on the role of compost in reducing soil-borne plant diseases is thoroughly reviewed by Zinati (2005) and Mehta et al. (2014) and indicates, that compost can be used to help fighting plant diseases and, hence, reduce the need for application of chemical pesticides.

[0011] Effect on water-holding capacity: Water is a factor which may easily disappear from the soil. The presence of organic matter contributes to improving soil water retention, other factors are soil texture and soil structure. With limited water retention of the soil, additional water supply will be necessary during dry seasons. Application of compost has been shown to positively affect the water retention of soil (Zemanek, 2011)

[0012] DE19753216 Al discloses a composting method for organic waste conducted in open or closed systems, wherein air is introduced into the waste via a pipe or gutter using a fan. Oxygen-enriched air is used to achieve the thermophilic phase, where the temperature is approx. 55 C to approx. 80 C, more quickly than by gassing with air alone. DE19753216 does not disclose measuring the content of nutrients in the organic waste material or in product resulting from the method.

[0013] There is a need for a sustainable solution to enhance climate resilience, soil fertility and improve practices for productions for farmers particularly such as coffee, maize and bean growing.

[0014] Summary of the invention

[0015] The present composting technology offers an alternative way of handling waste in a safe manner by hygienizing / sanitizing by use of the heat generated in the composting process. This allows recycling of the nutrients in the waste biomass, with only limited loss of nutrients during the process (primarily a limited proportion of N) compared to incineration where nearly all N is lost to the atmosphere. Hence, the biofertilizer / compost product can to a large extent replace chemical fertilizers. Also, application of compost to soil or growth substrate may increase the water-holding capacity which will improve plant growth and water use efficiency. Finally, the biofertilizer / compost product may have a suppressing effect on fungal plant diseases and may, therefore, reduce the use of chemical pesticides. Thus, use of the biofertilizer offers a multifaceted approach to building climate resilience, improving soil quality, water management and crop health, while stabilizing yield and contributing to sustainable waste management and economic resilience, particularly for small-scale farmers.

[0016] The production and utilization of compost in agricultural production is constrained by several factors. There is a risk of introducing soil borne pathogens which comprises biosecurity. Also, vegetative wastes are heterogeneous comprising materials which either are too succulent or woody due to high content of moisture and lignocellulose respectively. The excessive moisture in succulent type creates anaerobic environment during composting which facilitates excessive nutrient losses due to reduced microbial activity arising from low temperature. A high content of lignocellulose - a mixture of cellulose and lignin in woody materials resist biodegradation and consequently takes too long to produce quality compost.

[0017] The technology of the invention accelerates the composting of biomaterials into compost within 2 weeks or less, thus mitigating environmental pollution as well as strengthening ecofriendly agriculture.

[0018] Detailed Disclosure

[0019] Method for making organic fertilizer

[0020] The invention relates to methods for making organic fertilizer.

[0021] Organic fertilizer is in the present application and draft intended to mean a composition of organic material that can provide nutrients to crops growing on the same land area, e.g. a field; where the organic fertilizer is distributed. The organic fertilizer is prepared by a composting process and comprises a composition of partly decomposed organic material which upon distribution on the area where the crops are growing, or will be growing, will gradually be decomposed by the action of natural microorganisms releasing the nutrients so they become available to the crops.

[0022] The use of organic fertilizers, as the organic fertilizer of the invention, serves several different purposes, including increasing the yield of the crops and providing a convenient way of disposing of organic waste materials such as, plant material waste from agriculture gardening, waste material from household, plant processing and animal slaughtering processes and manure from livestock animals. Further, the use of organic fertilizers reduces or eliminates the need for inorganic fertilizers.

[0023] The methods for making organic fertilizer according to the invention provides organic fertilizers having a desired content of nutrients.

[0024] It is known that the soil may have different composition and content of nutrients depending on the location and historic use of the area, and further will different crops have different requirements, depending on the particular cultivated crop and the development state of a particular crop.

[0025] It is therefore important to be able to provide an organic fertilizer that can provide the nutrients required for a particular crop, which cannot be provided by the soil.

[0026] A soil analysis can be performed using a soil scanner. The soil scanner can deliver instant monitoring of nutrients in the soil. The scanner can perform near infrared spectroscopy and monitor the soil texture and soil macronutrients.

[0027] The nutrients can be any nutrients required for growth of the crop, including, but not limited to nitrogen (N), phosphorous (P), sulphate and further provide necessary mineral elements (or micronutrients) such as potassium (K), iron, magnesium, calcium etc. Preferred nutrients according to the invention are N, P and K.

[0028] It should be understood that nutrients should be provided in a form that can be taken up by plants. For example, nitrogen nutrients should be understood as nitrogen containing molecules that can be assimilated by plants, such as ammonia, urea, nitrate etc., and excluding nitrogen containing molecules that cannot, or only in a very small degree, be assimilated by plants, such as atmospheric nitrogen, that is abundant but only accessible by few plants living in symbiosis with specialized microorganisms. A source of phosphorus could be rock phosphate. It is a colloidal clay containing valuable phosphorus in addition to trace minerals. Since phosphorus is lacking in most soils, application of fertilizers with phosphorus is a must for superior results. Rock phosphate contains a minimum of 3 % available and 20 % total phosphoric acid (P2O5) and 20 % Calcium (Ca). Once applied, rock phosphate remains in the soil until used by the plants. It is ideal for fruiting and flowering plants. It stimulates strong root formation, hastens crop maturity and encourages earthworms and soil bacteria activities. Addition of rock phosphate to compost facilitates its dissolution because of the high organic matter content.

[0029] Another source of minerals are volcanic ash. Volcanic ash is a mixture of rock, mineral, and glass particles expelled from a volcano during a volcanic eruption. The particles are very small— less than 2 millimeters in diameter. Volcanic ash and rock dust contain minerals that are good for the soil and therefore, the plants. The ash consists of approximately 65% SiOz, 18% AI2O3, 5% FetO3, 2% MgO, 4% CaO, 4% NazO, and 0.1% S. Volcanic ash could be used to supply nutrients and reduce CO2 from the atmosphere. The weathering can draw CO2 from the atmosphere; in addition, volcanic ash with 0% carbon can turn into soils with around 10% organic carbon.

[0030] The ash holds air, and the air spaces it creates in soil can insulate plants against temperature change. It can also allow soil to hold water longer - encouraging both soil bacteria and seed germination, both of which are great for plant growth.

[0031] The preparation of the organic fertilizer of the invention takes place in a container wherein a composting process is taking place. Suitable containers are closed containers provided with means for air supply, means for measuring temperature and means for letting exhaust air out.

[0032] Means for air supply, measuring temperature and exhaust air outlets are all known in the art and the present invention is not limited to any particular such means, but it should be appreciated that the skilled person will be able to select such suitable means based on the general knowledge of compost processes and devices. One way of regulating the air supply is by supplying air when the oxygen concentration in the container is below a fixed value e.g. below 6-10% preferably below 8%. When oxygen concentration drops below the fixed value air is delivered, for example in amounts of 1-4 container volume preferably 2 container volume. Alternatively, air supply is continued until the oxygen concentration reaches a fixed value e.g. in the range of 16-19 %, preferably 18 %.

[0033] The method of producing organic fertilizer of the invention is started by providing the organic starting material in a particulate form.

[0034] Organic starting material can in principle be any form for organic material including plant, animal, insect or microorganism material or material directly or indirectly derived from such material including: any plant material, agricultural waste, waste from butcheries and food production facilities, household waste, manure, waste from municipal water treatment facilities, waste from microbial production processes, such as fermentation processes.

[0035] Examples of organic starting materials include cereal husks and straw, coffee husks, fruit residual materials, avocado residual material, waste from rice, cereal, corn and cacao production, and waste from animal (manure), insect, or any organic residue from food manufacturing, hotels and resorts as well as sorted household and municipality organic waste including sludge from wastewater treatment.

[0036] The organic starting material is converted into a particulate form. The skilled person will understand that the size of the particles of the organic starting material is important for the following composting process. Large particles are beneficial because they will generate voids in the organic starting material which facilitates the movement of air through the material, thereby facilitating air supply providing the oxygen supply for the composting process. However, the composting process is to a large degree performed by microbial growth which predominantly takes place on the surface of the particles so small particles favor the microbial decomposition.

[0037] The skilled person will therefore appreciate that there exists an optimal size of the particles of the particular material depending on the actual composition of the starting material, and further that the skilled person can determine the optimal size for a given composition based on simple experimentation.

[0038] It is preferred that the organic starting material has a particle size of < 40 mm, where the size is measured as the average length of the longest dimension of the particles, preferable < 40 mm, < 40 mm; and a size of > 1mm, preferably >2mm, >5mm or >10 mm. More preferred that starting material has an average particle size in the range of 1-40 mm, preferably 5-30 mm, preferably 15-25 mm and most preferred around 20 mm.

[0039] Preferred particle size is partly dependent on the starting material and thus where wooden materials are included in the starting material a particle size of < 20 mm is preferred. If the starting material is animal manure mixed with chaffs, husks or minced straw, a particle size of < 40 mm is preferred.

[0040] The invention is not limited to any particular technology for mincing the organic starting material, but any technology known in the art for mincing, cutting or chopping such material may be used.

[0041] After the organic starting material is provided in the particulate form it may be mixed to form a uniform material.

[0042] The organic starting material in particulate form and optionally mixed to form a uniform material, is next analyzed for the content of one of more selected nutrients of interest. Preferably the material is analyzed for the content of one or more of N, P and K.

[0043] The analysis can be performed using measuring technology known in the art.

[0044] If the measured content of one or more selected nutrients is below the desired content of the selected nutrient, the content of the selected nutrient can be increased by adding one or more booster materials. In this connection, booster materials are understood as organic or mineral materials having a high content of the selected nutrient. Booster material suitable for increasing the content of N includes: manure in particular from poultry, water hyacinth, waste material from proteinaceous foods and sludge from waste water treatment facilities.

[0045] Booster materials for increasing the content of P includes: manure in particular from feed stock, husks and mineral phosphates.

[0046] Booster materials for increasing the content of K are preferably selected among ashes.

[0047] If necessary, the moisture content of the starting material including any booster material is adjusted by adding water, in order to secure that the material has a sufficient high water content to allow an efficient composting. It is preferred that the water content is at least 40% - 60% w / w. Moisture is an important variable, since it provides a medium for the bacteria to facilitate decomposition.

[0048] When any booster materials have been added to the organic starting material the material is mixed and transferred to the container. The material should not be too compacted in the container in order to allow an efficient air flow through the material. It is preferred that the material has a density of less than 800 kg / m3, preferably less than 750 kg / m3, preferably less than 700 kg / m3.

[0049] The composting process is started by supplying air into the container and through the material. The start of the process can be observed by an increase in temperature because of microbial growth in the material.

[0050] The technology is reducing production time.

[0051] The temperature in the container is monitored in the organic material during the composting process until the temperature reaches 70°C. The composting process is continued for a sufficient period for hygienization / sanitation of the organic material, and during this period the temperature should be 70°C or higher. It is preferred that the temperature should not exceed 90°C in order to avoid spontaneous combustion of the material. One preferred way to keep the temperature below 90°C is to adjust / reduce the air supply in order to ensure that the growth rate of the composting microorganisms is reduced and consequently the generation and release of metabolic heat will also be reduced.

[0052] Hygienization / sanitation of the organic material is meant as a process of reducing or eliminating the number of harmful microorganisms in the material. Harmful microorganisms include pathogenic bacteria such a Escherichia coli, Salmonella sp., and Vibrio sp., that are desirable to remove in order to protect the handling staff against harmful infections; and plant pathogenic microorganisms, such as Fusarium sp., Rhizotonium sp., Ustilago sp., and Phytofthora sp., that are removed in order to protect the crops. Further, the hygienization process reduces the amount of plant seeds, in particular seeds for weeds, in the material.

[0053] Hygienization / sanitation may also be referred to as thermalization. These terms may be used interchangeably.

[0054] The skilled person can follow the hygienization / sanitation process, e.g. by taking samples at various time points from a test run and analyse the samples for the number of the relevant microorganisms. Alternatively, and suitable for most compost processes, it can be assumed that the hygienization / sanitation process is sufficient when the temperature has been maintained within the range of 70°C -90°C for a period of at least 60 minutes.

[0055] In some embodiments it may be desirable to add nitrogen-fixing bacteria to the material in the container and continue air supply for a further period in order to increase the nitrogen content of the organic fertilizer even further. In case that the selected nitrogen-fixing bacteria is not a thermophilic or thermoresistant organism it may be required to let the composting material cool to an optimal temperature for the nitrogen-fixing bacteria before adding these nitrogen fixing bacteria to the container.

[0056] As opposed to an open system where nitrogen will partly evaporate as ammonia, in a closed system nitrogen will be conserved, alternatively precipitated in the aqueous phase or in the evaporation which precipitates in the air filter cleaning. Naturally the atmosphere contains 78 % nitrogen and 21 % oxygen. The method of composting may comprising air being sucked into an airtight container, wherein the nitrogen rich air is assimilated by microbes of Azotobacter family during a composting process catalyzed by high temperature -producing compost with nitrogen levels as high as 4 %.

[0057] After the hygienization / sanitation step the air supply is discontinued and the obtained organic fertilizer can be removed from the container.

[0058] If desired, the content of a selected nutrient, preferably one or more of N, P and K; can be measured in order to confirm that the content is as expected based on the measurements made before the composting process.

[0059] In some embodiments the starting materials and optional boosters are selected to obtain a fertilizer with a NPK blending of 2:4:1 which is preferred at planting for Coffee, a NPK blending of 4:1:2 which is preferred for coffee in a vegetative state 2-4 months from planting or a NPK blending of 2:1:4 which is preferred for coffee for the fruiting state 10-15 months after planting.

[0060] Container / device:

[0061] The container for use in the method of the invention can in principle be any container suitable for composting processes as known in the area.

[0062] In a preferred embodiment the container is made with the dimensions of a standard transport container size, such as a 20 ft or a 40ft container. This is particularly beneficial because well-established transport systems for such containers are available almost everywhere, meaning that such composting containers easily can be transported to the desired areas.

[0063] In a preferred embodiment the container is a 20 ft container which allows for easy transportation and scalability by adding extra container units to the system.

[0064] It must be provided with means for air supply and means for letting out exhaust air. The means for air supply may be any such means such as a ventilator, or an air pump that can force a sufficient amount of air through the container. Examples of means for air supply are duct ventilators or other kinds of pressure fans.

[0065] The means for exhaust air may be provided simply as outlets where the exhaust air can escape the container. It may be provided with a net or grill to prevent escape of material from the container, or it may be provided as one or more chimneys provided on the container.

[0066] In some embodiments the means for exhaust air may be provided with a filter that can remove ammonia and / or foul-smelling compounds from the exhaust air.

[0067] The container is further provided with means to measure the temperature in the organic material being treated. The means to measure temperature is preferably provided as a probe that can be injected in the material being treated and measure the temperature at some distance from the surface of the container.

[0068] Preferably, the means to measure the temperature in the material is provided as three or more probes that can be inserted at different positions of the material, even more preferred, one is inserted and measures the temperature in the lower part of the material, one is inserted and measures the temperature in the middle of the material and one is inserted and measures the temperature in the upper part of the material.

[0069] It has been found that measuring the temperature at three or more different locations provides a better monitoring of the process.

[0070] The container may also be provided with a probe that can be inserted in the material and measure oxygen content. If such a probe is available it can be used to provide a better control of the process e.g. the air supply can be adjusted based on oxygen measurements, e.g. the air supply can be increased if oxygen content is low and reduced if oxygen content is high. The container may also be provided with a control system with technology that regulates and monitors the temperature and humidity of the biomass, thereby controlling the heat composting process. The control system comprises a Personal Logical Controller (PLC), aerator and sensors. PLC monitors and controls the composting process and can be operated at location or using remote control (cloud) making the technology very user friendly. PH determines the efficiency of the composting process. Microbes responsible for decomposition require a suitable pH range. The pH may be monitored throughout the process. The samples may be measured using a suspension of 1:2.5 (sample to water). The pH values of organic wastes suitable for composting is recommended in the range from 5-12. The pH of coffee husk is averagely 5.98 given the lower concentration of soluble salt.

[0071] Use of the fertilizer:

[0072] The organic fertilizer of the invention can be used as part of agricultural plant production.

[0073] The organic fertilizer can be spread on the fields at various times during the growth period of the plant, depending on the needs of the plant and the soil.

[0074] The organic fertilizer of the invention can be spread using equipment well known in the area, as no special procedures are required.

[0075] The organic fertilizer of the invention can be pelleted and packaged in moisture proof bags.

[0076] Benefits of invention:

[0077] The method of producing organic fertilizer of the invention has the benefit that it provides a method for producing an organic fertilizer with a desired N, P, K content.

[0078] It can process locally generated organic materials, thereby reducing the need for transportation and facilitate a circular economy, where waste materials can be processed and find new use in a different process. The method further provides optimal recirculation of nutrients (minimal loss) and improves uptake in plants.

[0079] The method is very time efficient and can provide compost from the desired material in 3-10 days.

[0080] The compost according to the invention has a very limited content of pathogens and the use of the compost for cultivating various crops may result in an improved growth of the plant and low incidence of plant diseases.

[0081] Figures

[0082] Fig. 1 shows schematic design of a container system for the method of the invention.

[0083] All cited references are incorporated by reference.

[0084] The accompanying Figures and Examples are provided to explain rather than limit the present invention. It will be clear to the person skilled in the art that aspects, embodiments, claims and any items of the present invention may be combined.

[0085] Unless otherwise mentioned, all percentages are in weight / weight. Unless otherwise mentioned, all measurements are conducted under standard conditions (ambient temperature and pressure). Unless otherwise mentioned, test conditions are according to European Pharmacopoeia 8.0.

[0086] Examples

[0087] Example 1, The composting / sanitization technology:

[0088] For this example two versions of a composting container were used, namely a container model with a reactor volume of 25 m3 and a silo model with a reactor volume of 6 m3. The two models used the same principle as well as hardware steering components, control- and monitoring software system. Both systems comprised inlets for air supply in the top and the bottom of the container, and outlet for exhaust air in the opposite end of the container. The exhaust air from the process was cleaned in a subsequent biological air cleaning filter based on rockwool, compost and straw. The air cleaner treated the exhaust gases from the composts process.

[0089] Further, the containers contained inlets where either temperature or oxygen probes could be inserted for measurements during test runs.

[0090] In operation, biomass was loaded into a composting chamber which was closed and controlled. Oxygen concentration and temperature were monitored during the composting process, and air was blown from the bottom or top of the chamber and through the biomass. The biological process developed heat, whereby the temperature in the material (biomass) rose to above 70°C in less than 48 hours, ensuring that the biomaterial was sanitized. Process parameters could be adjusted to the same level, e.g., the air flow per m3 of biomass.

[0091] The process was constantly monitored via a sensor system that continuously measured temperature and oxygen content throughout the entire process.

[0092] Temperature monitoring:

[0093] Temperature development during composting was measured by three PT100 sensors, which were placed at three different heights in the composting unit. In the container model, the sensors were placed 0.20, 0.85 and 1.50 m above the bottom of the container, with a total height of biomass at the beginning of the test run being 1.80 m. In the silo model, the sensors were placed 0.30, 0.75 and 1.20 m above the bottom of the silo, with a total height of biomass at the beginning of the test run being 1.50 m. Temperature was measured and logged every 2 minutes throughout each test run. Based on the obtained temperature data for each test run, the time to reach minimum 70°C for at least one hour for all three sensors was calculated. Also, the cumulative duration at >70°C was calculated for each of the three sensors. The same three sensors were used in the container model and in the silo model.

[0094] Oxygen monitoring

[0095] 02 concentration was measured in the air outlet of the composting chamber. The concentration of O2 in the air in the biomass was measured by the composting system. A perforated probe of minimum 0.5 m length was inserted horizontally in the side of the composting chamber, and by suction, air was sampled to the oxygen sensor with a range from 0 to 21% and logged every two minutes by the control system of the composting technology. Oxygen data were delivered by the proposer after the test runs.

[0096] The air flow in the air outlet of the composting chamber was measured by fan wheel anemometer in combination with registered ventilator performance.

[0097] Process data were collected and processed via a PLC, which then automatically controlled and optimized the process by regulating and controlling the oxygen supply. All process data was registered and saved continuously (log file). Real-time graph / curve of the process was monitored via SCADA Software (Supervisory control and data acquisition).

[0098] At oxygen levels below 8% air was supplied. The amount of air supply was approximately 2X container volume or until the oxygen level was above 18%. Alternatively, air supply was adjusted every hour. The air supply was reduced in case that the temperature reached 90C.

[0099] Example 2, Test runs with digested fiber fraction:

[0100] This example comprises two test runs conducted in the container model composting system described in example 1.

[0101] The tested organic starting material was a degassed fiber fraction from a biogas plant. The feedstock used in the biogas plant was approx. 90% slurry and deep litter from animal production with the remaining feedstock being mainly organic waste from dairy production. The fiber fraction was separated from the digestate by means of a screw press and a decanter centrifuge.

[0102] The digested fiber fraction was delivered from the biogas plant in two containers with one container being used for each of the two runs. The containers were weighed on a truck with weighing cells before and after unloading biomass to the composting chamber. The difference in weight corresponded to the weight of biomass loaded into the composting chamber. The biomass was loaded into the composting chamber with a truck grab, and 10 samples (approximately 1 kg each) of biomass samples were done for each at three stages during the filling. After filling, the chamber was closed, the three temperature sensors were inserted, and the test run was started. The test run was terminated, when the temperature had exceeded 70°C for at least one hour for all three temperature sensors.

[0103] Depending on the time of the day and week when the target temperature was reached, the chamber was opened and unloaded within 1-3 days. When the chamber was opened, the biomass was unloaded with a truck grab into a container. The final weight of the compost was determined by weighing the container before and after unloading. During unloading, biomass sampling was done as described for initial samples during filling of the compost chamber, i.e., with small samples taken 10 different places at three stages during the unloading process. In addition to three samples for analysis of nutrients, three samples of at least 30 L were sampled into perforated bags for later use in the trials related to fertilizer effect, suppression of plant diseases and effect on water-holding capacity. During storage, the bags were placed in one layer to avoid further heat generation and allow some drying and stabilization.

[0104] During the first test run, it was observed that the air flow through the air filter was insufficient and prevented sufficient aeration of the biomass in the composting chamber. Therefore, the air filter was removed during the test run, after which the composting process progressed as planned.

[0105] Consequently, the measurement of emissions during composting was only measured directly after the composting chamber and after the air filter. The temperature was > 70 for all three probes as can be seen in table 1:

[0106] Table 1: Key parameters for temperature development during the six composting test runs of examples 2-4.

[0107] Example 3, Test runs with sludge, garden waste and ash:

[0108] This example comprises two test runs conducted in the composting system described in example 1, wherein the composting system was a silo system.

[0109] The sludge was from municipal wastewater and the ash was Fly ash from combustion of straw delivered from a combined heat and power plant.

[0110] Garden waste was delivered from private gardens one or a few days before starting the test runs and consisted of leaves and branches from hedge cutting, lawn grass etc. Sludge was delivered in containers from a sludge depot.

[0111] Ash was delivered as dry material in barrels. In order to reduce the particle size of the garden waste and to obtain a homogeneous mixture of all three components, the components were loaded into a 1.5 m3 feed mixer which ran for approx. 20 minutes before loading into the composting reactor. This was done for four separate batches to achieve sufficient biomass mixture to fill the composting chamber. The feed mixer was placed on weighing cells, and the weight contribution from each component was recorded for each batch, and the total weight per component was calculated. In both test runs, the fresh mass distribution between the three biomasses was 85.4 % garden waste, 12.2 % sludge and 2.4 % ash. The mixing process resulted in a particle size of the garden waste of approx. 20-40 mm. For the second test run, the garden waste was lightly irrigated before chopping / mixing with the other components. The biomass mixture was loaded into the composting chamber with a truck grab. During filling of the chamber, three replicate samples were taken for nutrient analyses as described for test runs with degassed fiber, i.e., with each sample representing 30 subsamples. After filling, the chamber was closed, the three temperature sensors were inserted, and the test run was started. The test run was terminated, when the temperature had exceeded 70°C for at least one hour for all three temperature sensors. At this point, the aeration was terminated. Depending on the time of the day and week when the target temperature was reached, the chamber was opened and unloaded within 2 days. When the chamber was opened, the biomass was unloaded by turning the whole chamber with a truck crane and pouring the compost onto a concrete site. Samples for analysis of pathogenic bacteria and nutrient content were sampled by taking 30 subsamples per replicate sample from different locations in the biomass pile. In addition to three samples for analysis of nutrients, three samples of at least 30 L were sampled into perforated bags for later use in the trials related to fertilizer effect, suppression of plant diseases and effect on waterholding capacity. To achieve a more homogeneous compost product for these trials, the compost was run for 15 minutes in the feed mixer before sampling the 3*30 L. During storage, the bags were placed in one layer to avoid further heat generation and allow some drying and stabilization.

[0112] The time and temperatures for this example can be seen in table 1.

[0113] Example 4, Test runs with food waste and horse manure

[0114] This example comprises two test runs conducted in the composting system described in example 1, wherein the composting system was a silo system.

[0115] Food waste was collected from private households on Sealand.

[0116] The use of food waste (category 3 kitchen and food waste) for the experiment was approved by the Danish Food Authority (approval nr. DK-3-STP1251163). The food waste was processed into a biopulp by Gemidan, using the Gemidan Ecogi technology, (Hoisted Denmark) where process water is added, and the final pulp has a dry matter content of 17- 18%. The food waste for both test runs 1 and 2 was collected and processed and delivered to the test site in three IBC (Intermediate Bulk Container) of 1.000 L. The horse manure was delivered via private horse keepers, and the biomass contained a large proportion of straw. Food waste biopulp and horse manure were mixed in a Fimaks feed mixer (Bursa, Turkey) as described for the test runs with garden waste + sludge + ash. The weight of both food waste and horse manure was determined when loading into the feed mixer, and seven batches were mixed for each of the test runs to achieve enough material to fill the compost silo. Food waste constituted 27.6% and 24.1% of the initial fresh weight in test run 1 and 2, respectively. After mixing in the feed mixer, the particle size of the straw was typically 20-40 mm but with some particles both being larger and smaller. Since the food waste biopulp was rather wet, no water was added to the biomass before composting. The biomass was loaded into the compost silo with a truck grab as for the test runs with garden waste + sludge + ash. The silo was closed and insulated to minimize heat loss during the composting process. The aeration of the biomass was terminated when the temperature had exceeded 70°C for at least 12 hours for all three temperature sensors which was achieved within 1-2 days. For both test runs, however, the silo was first opened after a total of 7 days. After opening the silo, compost was removed from the silo by use of a truck grab.

[0117] Sampling before and after composting was done as described for test runs with garden waste + sludge + ash.

[0118] The time and temperatures for the experiments in this example are shown in table 1.

[0119] Example 5, Changes in nutrient concentration during composting

[0120] Changes in nutrient concentration and loss of total N during composting

[0121] For both test runs for all three biomasses, two replicate samples were taken for analyses of nutrient concentration before and after composting, leading to a total of 24 samples. The samples were analysed by Eurofins Agro Testing (Vejen, Denmark) for the following parameters:

[0122] • Dry matter content (DR109, EU 152 / 2009 mod., gravimetric method)

[0123] • Total N (DHN13, EF 152 / 2009 mod. / Kjeldahl, titrimetric)

[0124] • NH4-N (DHA07, EF 152 / 2009 mod / Kjeldahl, titrimetric)

[0125] • NO3-N + NO2-N (CAH66, DS 230:1998 / titremetric) • Total K (CA504, DS 259:2003, DS / EN ISO 11885:2009 / ICP-OES)

[0126] For the two test runs with degassed fiber fraction, the total weight of biomass was determined before and after composting. Based on these weights and the analyses of nutrient concentration, a mass balance was calculated for dry matter and total N during composting. The loss of dry matter and total N during composting was calculated as percentage of the initial quantity of dry matter and total N, respectively, in the biomass before composting.

[0127] Measurement of emissions and ammonia loss during composting

[0128] Emissions were measured in the two sanitization / composting runs with degassed fiber. A 6 mm PTFE tube was placed in the inlet and outlet of the sanitization / composting container as well as in the outlet of the biofilter for air cleaning, (see figure 1). Air was drawn through a heat-traced tube by a membrane pump (Capex L2 SE AC) (Reciprotor, Kpge Denmark), and into a Picarro G2508 cavity ringdown spectrometer (Santa Clara, CA, USA), that continuously measured the ammonia concentration. The system alternated between the measuring points using a multiplexer. At each measuring point the system measured for approximately 10 minutes, to ensure proper flushing of the tubing. Only the last few measurements were used, to ensure that no ammonia stuck in the tubing affected the results. The tube was heated from the membrane pump and into the Waste to Value system, to prevent condensation. Background concentration was determined by using an outdoor sampling line.

[0129] The hourly ammonia emissions were calculated based on the airflow and measured concentration of ammonia in the exhaust air. Calculated hourly ammonia emissions were used to calculate cumulated ammonia emission.

[0130] Loss of nitrogen during sanitization / composting was calculated based on the cumulative NH3 emission and calculated as a percentage of total N in the initial biomass. The loss of total N was 6.9%, from the 2. run, where the airfilter was bypassed. The composting process resulted in ammonia emission of no more than 10% of the total N content in the initial biomass.

[0131] Changes in nutrient concentration during composting and measurement of emissions of CChe and ammonia loss.

[0132] Changes in nutrient concentration and loss of total N during composting Dry matter content and content of N and K in biomass before and after composting is shown in table 2 for each of the six test runs.

[0133] Table 2: Concentration of N in biomass before and after composting of three different biomass mixtures in two test runs. For total N, the concentration is both calculated on fresh matter basis and dry matter basis. Values represent the mean and standard deviation of two replicate samples per biomass, test run and sampling time.

[0134]

[0135] Table 3: Concentration of K in biomass before and after composting of three different biomass mixtures in two test runs. For total K, the concentration is both calculated on fresh matter basis and dry matter basis. Values represent the mean and standard deviation of two replicate samples per biomass, test run and sampling time.

[0136] For the two test runs with degassed fiber fraction, the weight of dry matter and total N before and after composting was calculated by multiplying the fresh weight of the biomass with the concentration of dry matter and total N, respectively. The loss of dry matter and total N during composting was calculated as percentage of the initial quantity of dry matter and total N in the biomass before composting. The total weights and the loss of dry matter and total N is shown in table 4.

[0137] Table 4: Mass loss of fresh matter, dry matter and total N during composting test runs with digested fiber fraction:

[0138] Dry matter loss was 24.1% in test run 1 and 6.1% in test run 2. The loss of total N was 24.1 and 6.9%, respectively. The larger loss during test run 1 may partly be related to the longer duration of test run 1 (113.5 hours) compared to test run 2 (73.0 hours) and due to lack of sufficient aeration during the initial part of the first test run. Due to this, the estimated loss of N is not representative for test run 1.

[0139] Example 6, Analysis of plant nitrogen value

[0140] A growth experiment was performed in pots in a greenhouse to test the fertilizer effect of the three compost types. Initial analyses of compost:

[0141] For each biomass type, compost from test run 1 and test run 2 were mixed in equal proportions by volume to achieve a representative compost for the experiments with plant nitrogen value, suppression of plant diseases and water-holding capacity. For initial characterization of the three compost types, a sample of approx. 1 kg of each compost type was analysed by Eurofins for the following parameters:

[0142] • Dry matter content (DIN EN 13040: 2008-01 / Gravimetric, JYOBK)

[0143] • Total N (EF 152 / 2009 mod / Kjelda h I, titrimetric, DHN13) • Ammonium N (EF 152 / 2009 mod / Kjeldahl, titrimetric, DHA07)

[0144] • Nitrite + nitrate N (DS 223 / DS 230:1988 mod. / Titrimetry, CAH66)

[0145] • Total P (DS 259:2003, DS / EN ISO 11885:2009 / ICP-OES, CA503)

[0146] • Total K (DS 259:2003, DS / EN ISO 11885:2009 / ICP-OES, CA504) • Total Mg (DIN EN 13650:2002-01, JYOBT)

[0147] • Total Ca (DIN EN 13650:2002-01, JYOBS)

[0148] • Total S (DIN EN 13650:2002-01, JYOHK)

[0149] • Density (Methodenbuch zur Analyse organischer Dungemittel, / Gravimetric, JY08Y)

[0150] • Total C (ISO 10694 / Dumas, TCD, CAH0M) • C / N ratio (calculated, DR323)

[0151] • pH (Internal Method Radiometer, GLP / Potentiometric, DHR01)

[0152] • Electrical conductivity and salt (EC) (DIN EN 13038: 2012-01 / Conductometric, JY07A)

[0153] The analyses of the three compost types used in the experiment are shown in table 5.

[0154] Table 5: Analysis of compost prior to various plant tests regarding nitrogen fertilizer effect and disease suppression effect.

[0155] Soil / growth substrate:

[0156] The sand mixture 'Dansand® Topdressing 50V' was used as the basic growth substrate. This has a large proportion of coarse sand (approx. 99%) and a low content of organic matter and nutrients, and the texture resembles that of coarse sandy soil type (JB1) in the Danish soil classification system.

[0157] Plant species: The experiment was performed with tomato (Solanum Lycopersicum) grown from small seedlings of the cultivar Money Maker. The tomato seeds were sown in peat-based substrate from Pindstrup, DK and then transferred to the following treatments.

[0158] Experimental design

[0159] Each of the three types of sanitized compost were mixed into the sand at two different proportions. As reference, plants were grown in pure sand with no fertilization or full fertilization with chemical fertilizer suitable for tomatoes. The experiment included the following 8 treatments:

[0160] 1. 100% Sand without N fertilization

[0161] 2. 100% Sand + full nutrient solution with N

[0162] 3. 75% sand + 25% compost 1 without N fertilization

[0163] 4. 50% sand + 50% compost 1 without N fertilization

[0164] 5. 75% sand + 25% compost 2 without N fertilization

[0165] 6. 50% sand + 50% compost 2 without N fertilization

[0166] 7. 75% sand + 25% compost 3 without N fertilization

[0167] 8. 50% sand + 50% compost 3 without N fertilization

[0168] The proportion was set based on analyses of the nutrient content and electric conductivity (EC) of the three specific compost batches. To ensure the N from the composts can be comparable with the N from full nutrient solution, the proportion of compost were increased from 15% to 25% and from 30% to 50%. The same proportions were applied for all three sanitized composts.

[0169] Each treatment was done in six replicate pots of about 0.5 L volume, giving a total of 48 pots.

[0170] Duration and fertilization: The plants were grown for 8 weeks. In the treatments, 100% without N fertilization (1) and with full nutrient solution (2) were controls. Chemical fertilizer was added continuously to ensure non-limiting conditions in each substrate. Each substrate had their respective tank to provide nutrition solution in case there is any interference between substrates.

[0171] Irrigation: The pots were drip irrigated to keep an optimal irrigation.

[0172] Light and temperature: Tomatoes were grown in state-of-the-art greenhouses, under optimal conditions for aboveground part. Supplemental light was given when light level reached values bellow 300 pmol per square meter; temperature was set at 25 / 20°C Day / night; and relative humidity of 65%.

[0173] Measurements of the fertilizer effect of N in sanitized compost: At the end of the experiment, plant height and total above ground biomass production (fresh matter and dry matter) were measured for six plants per treatment.

[0174] Analysis of total N was performed by AgroLab. Total uptake of N was calculated based on analysis of 3 plants.

[0175] Data analysis: The average plant weight (fresh weight and dry weight) was calculated from the replicate pots and the mean and standard deviation was calculated. A linear doseresponse relationship was calculated for plant dry weight for the treatments with no fertilization and full fertilization with mineral fertilizer. The mineral nitrogen fertilizer efficiency of the sanitized compost types and doses were estimated by use of the doseresponse relationship for mineral N fertilization: Based on the applied dose of total mineral nitrogen (sum of ammonium-N, nitrite-N and nitrate-N) with the compost, the predicted plant dry weight was calculated for each of the compost types and doses, and the measured plant dry weight was calculated as a percentage of the predicted plant dry weight. This results in a measure of mineral nitrogen fertilizer efficiency.

[0176] A mixture of 25% compost / sand for compost 1 and 2 had a higher plant dry weight than predicted for the given dose of fertilizer. The mineral N fertilizer efficiency was 112% at a dose of 25% compost in the mixture whereas it was 83-84% at a dose of 50% compost in the mixture. For compost 3, the mineral N fertilizer efficiency was considerably lower with 50 and 34% in mixtures with 25 and 50% of compost, respectively. 25% compost / sand mixture of compost 1 and 2 is verified as corresponding to at least 90% of the plant growth obtained by equivalent quantities of N from conventional chemical fertilizer.

[0177] Plant height was measured for, plant fresh and plant dry weight at termination of the experiment. Generally, the plants grown in 100% sand with full N showed the highest biomass accumulation, while that grown in 100% sand with no N showed the least. However, when the compost was added to the sand, the biomass accumulation was increased, no matter if it was compost 1, 2 or 3. Moreover, for compost 1 and 2, the mixture with 50% compost gave a stronger plant response than the mixture with 25% compost, indicating the effect of dose of compost on plant growth. Moreover, the leaf nitrogen content in full nutrient solution was higher than that of the other treatments, but that of the other 7 treatments were at similar level.

[0178] The experiment showed that two of the compost treatments had higher plant dry weight than the value predicted for the given dose of mineral nitrogen per pot which indicates a mineral nitrogen fertilizer efficiency above 100%. The calculated mineral nitrogen fertilizer efficiencies are shown in table 6.

[0179] Tabel 6: Calculated mineral N use efficiency for the mineral N applied with the compost in the growth experiment with tomato plants. The N fertilizer efficiency was calculated based on the dose-response relationship for plant dry weight for mineral fertilizer.

[0180] For all three compost types, the mineral N fertilizer efficiency was highest for the mixtures with 25% compost compared to the mixtures with 50% compost. For both compost 1 and 2, the mineral N fertilizer efficiency was 112% at a dose of 25% compost in the mixture whereas it was 83-84% at a dose of 50% compost in the mixture. For compost 3, the mineral N fertilizer efficiency was considerably lower with 50 and 34% in mixtures with 25 and 50% of compost, respectively.

[0181] The reason why 25% mix results in a higher mineral N use efficiency could be explained with some kind of inhibition at higher mineral concentrations. Immature compost with high levels of nitrogen and salts can burn seedling roots. The growth of tomato plants was improved in substrate mixtures with compost compared to pure, unfertilized sand, and the plant dry weight increased with increasing dose of mineral nitrogen (ammonium+ nitrite + nitrate) applied per pot with the compost which proves the N fertilizer effect of the compost.

[0182] Example 7, Analysis of availability of P in ash before and after composting:

[0183] In order to test the effect of composting on plant availability of P in biomass enriched with ash, biomass samples were analyzed before and after the sanitization / composting process. This was done for the two test runs with the biomass mixture of garden waste + sludge + ash which was sanitized / composted in the silo model of the sanitization / composting system. Two samples were taken from the biomass just before and just after each of the two composting test runs as described previously, resulting in a total of 2*4 = 8 samples. The samples were frozen until analysis. Analysis was done by Eurofins Agro Testing Denmark. The P content was analyzed by extraction with nitric acid, neutral ammonium citrate and water, respectively, by use of the following analyses:

[0184] • Total P (DS 259:2003, DS / EN ISO 11885:2009 / ICP-OES, CA503)

[0185] • Citrate soluble P (Metode for jordforb. dell: 3.1.4: 1978, SM 3120, ICP-OES, A142+CAI31+CAI33)

[0186] • Water soluble P (DS 259:2003, SM 3120, ICP-OES, CAE49+CAA26)

[0187] Data analysis: For each of the 8 samples, the fractions of citrate-extractable P and water- extractable P, respectively, were calculated as percentage of total P. The effect of composting on phosphorus availability in the biomass was evaluated by analysis of variance. Separate data analyses were performed for the parameters total N, total K, total P, citrate soluble P, water soluble P, all expressed as kg per ton dry matter, as well as the fraction of citrate-extractable P and water-extractable P. In the analysis, composting was included as a systematic effect whereas test runs and replicates within test runs were not included in the model. The concentration of N, K and P as well as the fraction of citrate-extractable and water- extractable P in the biomass before and after composting of garden waste + sludge + ash is shown in table 7.

[0188] Table 7: Concentration of N, P and K in biomass before and after composting of garden waste + sludge + ash in two test runs. For phosphorous, the content was both analysed as total P, water soluble P and citrate soluble P. Values represent the mean of two replicate samples per test run and sampling time. The P value is given for the effect of composting on the mean value of each of the parameters, and letters indicate significant differences; within a parameter, mean values with the same letter are not significantly different. For both N, P and K, there was a tendency towards higher concentration in dry matter after composting than before composting, indicating an up-concentration effect of the composting process on the nutrient content. This was most pronounced for K and P with an increase of 19.8 and 14.5%, respectively, however, none of the increases were statistically significant (P = 0.473, 0.190 and 0.101 for N, K and P, respectively). The concentration of citrate-extractable P in DM was significantly higher after composting than before composting (P=0.045), corresponding to an increase of 5.7%. The concentration of water- extractable P was 9.3% higher after composting but the difference was not significant (P = 0.423). The fraction of citrate-extractable and water-extractable P as percent of total P was slightly decreased during composting with 5.9 and 1.3 percentage points, respectively, but with no significant difference before and after composting (P = 0.281 and 0.803, respectively). Therefore, the example did not demonstrate that the plant availability of P in the biomass was increased by the composting process.

[0189] Example 8, Test of effect of compost on fungal diseases

[0190] A disease suppression experiment was performed in pots in a greenhouse to test the effect of the three sanitized compost types. The three types of sanitized compost consisted of a mixture from the two individual test runs for each of the three biomasses, as described for the test of fertilizer effect.

[0191] Plant species: The experiment was performed with tomato (Solanum Lycopersicum) grown from small seedlings of the cultivar Borsalina.

[0192] Pathogen species: The experiment was performed with two fungal plant diseases Fusarium and Rhizoctonia. Fusarium oxysporum f. sp. lycopersici causes wilting of tomato, and Fusarium oxysporum is amongst the most important and diverse phytopathogenic fungi infecting almost 150 plant species, the specific pathogen of each species is described as a 'formae speciales (f. sp.)'.

[0193] The fungal species Rhizoctonia represents one of the many phytopathogenic genera that compromise root development of many different plants and thus the growth rate of seedlings as well as the productivity of plants that reach maturity. In cases where root compromising pathogens become prominent, the plants may die and require extensive sanitation of production facility, losing valuable production time.

[0194] Soil / growing medium: As basic growing medium was used potting soil from Weibulls Horto AB. The growing medium was fully fertilized and supplemented with 10% (by volume) of Dansand® Topdressing 50V (as described in the N fertilizer effect experiment), Braedstrup, DK.

[0195] Experimental design: The experiment was designed as a split-plot design with soil type as whole-plot factor, plant disease as sub-plot factor and with three replicate blocks, each consisting of three pots per combination of soil type, plant disease and replicate.

[0196] The soil factor consisted of the following 4 treatments:

[0197] 1. 100% soil

[0198] 2. 85% soil + 15% sanitized compost 1

[0199] 3. 85% soil + 15% sanitized compost 2

[0200] 4. 85% soil + 15% sanitized compost 3

[0201] Each of the three types of sanitized compost was mixed into the mixture of potting soil and sand (90% Weibull Horto + 10% Dansand Topdressing, referred to below as 'soil') by use of a concrete mixer. As reference, plants were grown in pure soil without addition of compost. The analyses of the three compost types used in the experiment are shown in table 5.

[0202] The plant disease factor consisted of the following three treatments:

[0203] 1. Uninfected, i.e., no plant disease added.

[0204] 2. Infection with Fusarium

[0205] 3. Infection with Rhizoctonia

[0206] For each of the 4*3=12 combinations of soil type and plant disease, 9 tomato plants were grown in individual pots leading to a total of 12*9=108 plants in the experiment. The 9 plants per combination were allocated to three replicates, each consisting of three plants. Preparation of tomato plants:

[0207] Tomato seeds were sown in Eazyplugs which were soaked in water (pH 6.) the day before. After sowing, the plugs were placed in a mini-greenhouse in a growth cabinet at 23-24°C. After a week, the temperature was changed to 15-16°C and 6-7 hours light per day. After 28 days from sowing, the tomato seedlings were transplanted to 5 L pots with the 4 different soil types.

[0208] Cultivation of plant pathogens and infection of plants:

[0209] The two fungal species Fusarium and Rhizoctonia were grown on PCA agar for 4 months before the start of the experiment. All work was carried out sterile. At start-up, 4 Petri dishes (9 cm) were inoculated with Fusarium and Rhizoctonia respectively (2 dishes per species). After 2-3 weeks, the fungi were transferred to new plates with fresh medium by cutting plugs of each fungus. 2 plugs with the fungus were placed on each Petri dish. New plates were made regularly for both fungi for 4 months.

[0210] For infection of the tomato plants, a fungal solution was prepared. All plates with fungi were mixed and blended. Water was added to the mixture to end up with 8 L solution per fungal species. The concentration of fungal spores in the solutions were determined by cell count in a counting chamber. The potted tomato plants were infected with fungal diseases by adding either 2 dL of Fusarium solution + 2 dL of water or 2 dL of Rhizoctonia solution + 2 dL of water to each pot. For uninfected plants, 4 dL of water was added. The plants with various treatments were placed in trays on tables in a greenhouse as shown on the figure above with the experimental design.

[0211] Fertilization and irrigation: The pots were irrigated manually from the top when needed. Based on analyses of the nutrient content in the compost and soil mixtures, it was decided not to apply any extra fertilizer, as the nutrient level was considered to be adequate.

[0212] Light and temperature: Tomatoes were grown in state-of-art greenhouses under conditions optimal for tomato production. The tomatoes were grown at 16 hours of light and 8 hours of darkness with a temperature range of 18-30°C. The temperature was set to a minimum of 15-162C. Artificial light was switched on, so light was on for 6-7 hours (50-60 w / m2).

[0213] Measurements of disease suppression effect of the compost: The health status of the plants was assessed weekly throughout the experiment for Fusarium. Disease symptoms were scored according to the severity scale reported by (Rongai et al. 2017):

[0214] 0 = No symptoms

[0215] 1 = Slight yellowing of one or two leaves

[0216] 2 = More extensive yellowing of basal and medium leaves, with some leaves wilted

[0217] 3 = Severe yellowing of leaves, 50 % of leaves wilted and growth inhibited

[0218] 4 = Widespread symptoms, all leaves yellow, rot on roots, vascular discoloration in the stem, severe stunting

[0219] 5 = Plant dead

[0220] A disease severity index was calculated for each treatment combination based on the scoring on the severity scale and calculated as described by Chiang et al. 2017:

[0221] There were no disease symptoms until week 3 after infection of the plants, so disease severity index for Fusarium was only available after 3, 4, 5 and 6 weeks after the infection of the plants.

[0222] The experiment was terminated 43 days after infection with plant pathogens, and final evaluation was done of each individual plant. A score was given according to the severity disease index to each plant based on symptoms for Fusarium. For assessment of Rhizoctonia, the main stem was cut open to evaluate the occurrence of black rot. Height and weight of the above-ground biomass (fresh weight) was determined for each plant.

[0223] Data analysis: Data were analysed using the statistical software R version 2022.07.2 Build 576. Analysis of variance was carried out for each of the response variables: Disease severity index for Fusarium after 3, 4, 5 and 6 weeks and for Rhizoctonia after 6 weeks, plant height after 6 months as well as plant fresh weight after 6 weeks. The analyses of plant disease indices were based on 36 observations which were each calculated based on three plants.

[0224] The analysis of plant weight and plant height was based on 108 observations, corresponding to individual plants. For all response variables, the model included the main factors soil type and plant disease as well as their interaction. Moreover, a block factor was included. Normal distribution of data was checked by a Shapiro-Wilk normality test, and the model fit was evaluated from residual plot.

[0225] Infection of tomato plants with Fusarium and Rhizoctonia reduced plant height significantly with 14- 23% and plant weight significantly with 10-22% compared to uninfected plants. This indicates that infection of both fungal plant diseases reduced tomato plant growth significantly, although the infection was not reflected in the disease severity index.

[0226] Table 8: Estimated values for disease severity, plant height and plant weight in the plant disease suppression experiment which was running 6 weeks after infection. Letters indicate LSD groupings within soil type; within a parameter and within a soil type, values followed by the same letter are not significantly different (P=0.05).

[0227] Addition of 15% of compost 2 or compost 3 resulted in growth of infected plants that was not significantly different from the growth of uninfected plants. Addition of 15% of compost 1 also resulted in plant growth which did not differ significantly between plants infected with Fusarium and uninfected plants, whereas plants infected with Rhizoctonia had poorer growth. Overall, the results indicate that addition of the tested compost types can have a significant protection against the negative effect of the two fungal diseases on growth of tomato plants. It is verified that compost 1 and 2 has a statistically significant protection effect against the fungal plant diseases Fusarium and Rhizoctonia.

[0228] Example 9, Test of effect of compost on water-holding capacity

[0229] A pot experiment was carried out to determine the effect of three types of sanitized compost on the water-holding capacity of growth substrate (Tian et al., 2012). The three types of sanitized compost consisted of a mixture from the two individual test runs for each of the three biomasses, as described for the test of fertilizer effect.

[0230] Experimental design: Sand was used as the basic growth substrate, as described for the growth experiment with test of fertilization effect of sanitized compost. Each of the three types of sanitized compost was mixed into the sand at two different proportions, and pure sand served as a control. The experiment included the following 7 treatments:

[0231] 1. Sand without compost

[0232] 2. 75% sand + 25% sanitized compost 1

[0233] 3. 50% sand + 50% sanitized compost 1

[0234] 4. 75% sand + 25% sanitized compost 2

[0235] 5. 50% sand + 50% sanitized compost 2

[0236] 6. 75% sand + 25% sanitized compost 3

[0237] 7. 50% sand + 50% sanitized compost 3

[0238] The specific proportions of sand and sanitized compost were adjusted as mentioned for the growth experiment with N fertilization effect. Each treatment was done in three replicate pots of about 0.5 L volume, giving a total of 21 pots. The pots were filled with substrate and compacted equally by consolidating with the same mass on top of the substrate.

[0239] The pots were fully saturated with water and weighed and allowed to drain for 24 hours and then weighed again. Each pot was then placed on gravimetric scales (drought spotter, phenospex) in a controlled room with temperature set at 30°C. Evaporation rate (without plant growth) was calculated by the weight loss of the pots for 2 weeks. Pot weight was logged every 5 minutes. At the end of 2 weeks, pots were dried for 48 hours at 80°C in a drying oven to determine the residual water in the substrates.

[0240] Table 9: below shows the pot weight at full saturation, after draining for 24 hours and after evaporation for two weeks at 30°C. The pot weight with the fully saturated substrates were similar for 100% sand, 75% sand + 25% compost of type 2 and 3, while that of the other substrates were lower than for 100% sand. This reflects that the bulk density is lower for compost than for sand and addition of compost decreases the bulk density of the mixtures. Generally, the pot weight of fully saturated substrates and substrates drained for 24 h were at the same level, whereas the pot weight was considerably lower after evaporation for two weeks. After two weeks, the pot weight of 100% sand and 75% sand + 25% compost of type 2 and 3 were similar, which were higher than the other substrates.

[0241] The range of the decrease in pot weight after 2 weeks was bigger, ranging from 17% to 24%. A higher weight loss during the two weeks indicates a larger content of plant-available water. Here, addition of either 25% and especially 50% of compost 3 resulted in a higher relative weight loss compared to pure sand. However, the actual weight loss per pot indicates the actual content of water - available water per pot, and this was generally lower for substrates with compost compared to pure sand, except for addition of 25% of compost 3, where the weight of plant-available water was 173.7 g per pot compared to 166.1 g for pure sand, corresponding to an increase in 4.6 volume percent.

[0242] Data analysis: The full turgidity (calculated 24 hours after full saturation of pots) was used to calculate the air volume at field capacity. The difference in weight between field capacity and oven-drying at 30°C divided by the volume was used to calculate the amount of plant available water present in the substrate mix. The average value and standard deviation were calculated.

[0243] Addition of compost to sand decreased the bulk density and increased the air volume of the substrate mixture at field capacity. The content of plant-available water per pot was increased by 4.6 volume percent when adding 25% compost 3 to sand whereas other treatments with compost reduced the content of plant-available water.

[0244] Example 10: Organic fertilizer product: Table 10 shows the composition of a formulation of a biofertilizer:

[0245] Table 10: The composition of raw material for formulation of a biofertilizer.

[0246] A biofertilizer was produced using a composting system according to example 1. The system is designed as a closed container with controlled aeration system. Biomass was loaded in the composting chamber that doubled as a sanitization chamber as well, which was closed and controlled with automated system for monitoring temperature and oxygen concentration. The biological process developed heat as microbes acted on the biomass raising temperature above 70 °C in less than 48 hours. The increased temperature sanitized biomass against germs and helped to inactivate weed seeds present in the compost. The moisture level was kept at around 60 %. Co-composting of coffee husks with high organic carbon content with readily bio-degradable organic material accelerated the shift from mesophilic to thermophilic phase attaining a temperature of 70 °C in two days.

[0247] Total organic carbon, nitrogen and phosphorus were determined in filtered extract using a spectrophotometer at 600 nm, 650 nm and 880 nm respectively. Potassium (K), Calcium (Ca), Magnesium (Mg) and other minor elements were determined by spectral method, using x-ray fluorescent (XRF) analyzer. The nutrient composition of the biofertilizer is shown in table 11.

[0248] Table 11: The nutrient composition of the biofertilizer. Efficacy of the biofertilizer was demonstrated at farm level on beans, coffee and maize.

[0249] Beans:

[0250] Beans were subjected to four treatments: control (Tl); 1 kg per plot (T2); 2 kg per plot (T3); and 3 kg per plot (T4). The plot size was 16 M2. The biofertilizer increased plant height, canopy width, number of pods per plant and yield in general (Table 12 below). The optimum performance was noted at 2 kg per plot.

[0251] Table 12: Efficacy of biofertilizer on beans:

[0252] Maize:

[0253] Maize was subjected to five treatments: control (Tl); 1 kg (T2); 2 kg (T3); 3 kg (T4); 4 kg (5); and 5 kg (T6) Each plot was 16 square meters. The biofertilizer enhanced maize plant height, stem width and number of leaves per plant. There was increased number of seeds per plant, seed weight and yield per acre (Table 16 below). Optimum yield was attained at a treatment of 3 kg per 16 M2plot.

[0254] Table 13: Efficacy of biofertilizer on maize: Coffee:

[0255] On coffee, there were four treatments: no fertilizer (control); 1 kg (Tl); 2 kg (T2); and 3 kg (T3). There was an increase in the number of leaves per plant, enhanced chlorophyll pigmentation and development of new branches (Table 17 below). Optimum response was noted in T3 Table 14: Efficacy of biofertilizer on (young) Coffee

[0256] The recommended application rates based on the results above were beans: 500 kg / acre; maize: 750 kg / acre; and young coffee: 3 kg / coffee tree. This confirms that crop wastes such as coffee husk, kitchen peels and market refuse can be transformed into valuable organic fertilizer by using the composting method according to example 1.

[0257] Coffee husk, if unattended to, becomes potential threat for proliferation of Fusarium wilt.

[0258] Composting thus provides a sanitization treatment to ensure the risk of exposure of crops to disease inoculum is curtailed. Secondly, composting enables farmers to minimize pile-up of husk. It breaks down coffee by-products through oxygen-driven biological process.

[0259] Example 11, Effects of enriched market-waste compost on crop productivity

[0260] Zea Mays L. (Maize) and Phaseolus vulgaris (common bean) were used as test crops. Two separate experiments were conducted, one for each crop. The study was carried out in Uganda, where the crop yield is 1.5 tons per hectare (t / ha) and 500-800 kg / ha for maize and beans respectively. The experimental plot design was based on a split-plot with main plots arranged as Randomized Complete Block Design (RCBD) in four replicates. Each treatment was applied on an individual plot of 4.0 m x 4.0 m.

[0261] The main plots were compost mixed with Rock Phosphate (RP), Volcanic ash, Urea, Diammonium Phosphate (DAP), Muriate of Potash (MOP), all mixed with and no fertilizer (Control)) applications.

[0262] The beans experiment

[0263] For every 100 kg of compost, 6 kg of volcanic ash, 6 kg of rock phosphate, 12 kg of urea, 4 kg of DAP, and 4 kg of MOP were added. The treatments were: No fertilizer 0 kg (Control), 0.987 kg(T2), 1.975 kg (T3), 2.963 kg (T4), 3.950 kg (T5), 4.935 kg (T6) in 0.00395 acres. This means that in an acre, T1 = 0 kg, T2 = 250 kg, T3 = 500 kg, T4 = 750 kg, T5 = 1,000 kg, and T6 = 1,250 kg.

[0264] Beans (variety NABE 12), were planted at a spacing 50 cm x 20 cm (MAAIF (Ministry of Agriculture, Animal Industry and Fisheries, Uganda), n.d.-a)

[0265] The maize experiment

[0266] For every 100 kg of compost, 15 kg of volcanic ash, 15 kg of rock phosphate, 15 kg of urea, 5 kg of DAP, and 5 kg of MOP were added. The treatments were: No fertilizer 0 kg (Control), 0.987 kg (T2), 1.975 kg (T3), 2.963 kg (T4), 3.950 kg (T5), 4.935 kg (T6).

[0267] Maize (variety Longe 5), was planted at a spacing of 75cm x 25 cm (MAAIF, n.d.-b).

[0268] For both Maize and beans planting was done at the onset of rainfall in September 2021. The plots were weeded twice.

[0269] Field management and harvesting were done following standard agronomic practices.

[0270] Compost for use in this evaluation was randomly obtained from various batches of compost. The compost used was generated at a biofertilizer plant using a method according to a container model composting system described in example 1. The compost was oven-dried at 65-70 C for 48 hours for constant weight and ground ready for analysis. The results of the analysis can be seen in table 15.

[0271] Table 15. Analysis of compost:

[0272] Crop growth was monitored by measuring the plant height of 6 plants in the center of each plot. The crop was harvested once it had completed its physiological maturity, and its dry matter content was about 30%. At harvest, 6 whole plants were randomly selected from each plot and were harvested by hand.

[0273] Crop above-ground dry matter (DM) yield was determined by drying maize cobs and bean seeds at 60°C until constant weight, and the rest of the plants at 105°C for 26 hours.

[0274] The effect of compost application was assessed in the laboratory by measuring crop yield through weighing. The results for beans can be seen in table 16 and the results from maize in table 17

[0275] Table 16: Response of bean seed yield to application of compost:

[0276] Plant height: It was seen that the compost had an effect on plant height at 6 weeks after planting (WAP), as shown by an increase in plant height in all treatments compared to the control, Tl. The greatest plant height (22cm) obtained from treatments T3 (5OOKg / acre), T4 (750kg / acre), and T6 (l,250kg / acre). The control Tl had the shortest plants. (Table 16).

[0277] Number of leaves: It was also seen that the compost had an effect on the number of leaves on the maize plant at 6 WAP, as shown by the increase in the number of leaves in all treatments compared to Tl. Treatment T6 (l,250kg / acre) had the greatest number of leaves followed by T4 (750kg / acre) with the control and T5 (l,000kg / acre) having the least number of leaves

[0278] Weight of shoots and roots: Plants in treatment T6 had the heaviest shoots (343g) and control, treatment Tl had the lightest shoots (252g). Treatment T6 had the heaviest roots (24g) while Tl had the lightest roots (18g).

[0279] Number of pods and seeds per pod: Treatment T5 had the highest number of pods (15 pods) but also had the least number of seeds per pod (2 seeds per pod) while treatment Tl had the least number of pods (7 seeds per pod). Treatments Tl, T2, T3, T4, and T6 the same number of seeds per pod (3 seeds per pod).

[0280] Yield: There was a difference in all treatments compared to the control, Tl. Treatment T3 had the highest yield (1.3 tons / acre), followed by treatment T5 (1.2 tons / acre). The control had the lowest yield (0.8 tons / acre). Compared to the control treatment, bean yield was increased by 34% in treatment T2 62% in treatment T3, 41% in treatment T4, 51% in treatment T5 and 35% in treatment T6.

[0281] Table 17: Response of maize grain yield to application of compost:

[0282] Plant height: The compost had an effect on plant height at 6 weeks after planting (WAP), with the greatest plant height (104cm) obtained from treatments T5. Treatment T3 had the shortest plants (85cm). Number of leaves: the compost had an effect on the number of leaves on the maize plant at 6 WAP, with all treatments having the same number of leaves except treatment T5 with an average of 6 leaves.

[0283] Yield: there was a difference in the yield of maize when the compost was applied to maize. Treatment T4 had the highest yield (5 t / acre), followed by treatments T6, and T3 (4.9 t / acre). The control had the lowest yield (4.1 t / acre). The percent increase in yield in T2, T3, T4, T5, and T6, over absolute control was around 17, 19, 23, 11, and 20 percent, respectively.

[0284] The bean yield obtained from all treatments was above the average bean yield obtained from smallholder farmer gardens (0.25t / acre) while the maize yield obtained from all treatments was well above the average maize yield of Uganda, which is between 0.89 - 1.0 t / acre (MAAIF, n.d).

[0285] The study indicates that compost generated from the Biofertiliser plant is a valuable fertilizer whose use needs to be encouraged. An application rate of 0.5 t / acre was capable of increasing bean yields by more than 63% over the control. The application rate of 0.75 t / ha increased maize yield by 21% over the control.

[0286] The results showed that an increase in quantities of compost does not necessarily increase the yields of beans and maize. It is therefore important to understand the actual component ratios (rock phosphate, urea, tithonia, volcanic ash) required to get maximum crop yield.

[0287] The results obtained in this experiment are of significant importance for low-input farming systems where access to mineral fertilizers is a major production constraint.

[0288] Example 12 Biomass input and biofertilizer output

[0289] A 20-foot container customized to the method of example 1 has the capacity to compost 20 MT of sorted organic waste to produce 17 MT of biofertilizer. The process takes place in a closed and controlled environment, whereby microorganisms are degraded transforming biomass into a mixture of mineralized and organic composition: compost. The technology is reducing production time, giving farmers access to cost effective and reliable biofertilizers. The aerobic process was activated by blowing in oxygen over the biomass using an aerator. After 24-48 hours the biomass reached 70 °C and this temperature was kept for the next 24 hours whereby pathogenic bacteria, protozoa and weed seed were destroyed. This process also started the chemical breakdown of the biomass. The composting process was constantly monitored by a control system monitoring and controlling temperature and oxygen content. Within another 3 days the material had become a dark brown colored and sweet smelling humus with high organic matter.

[0290] The available biomass used was crop residues and plant sections such as stems and fruits wastes, but also other locally available biodegradable wastes. The fertilizer will contain four major components: Compost, Tithonia, Rock Phosphate and volcanic ash for organic matter, nitrogen, phosphorus and potassium respectively. The different ratios in which the constituents of the fertilizer was mixed depended on the growth stage of the plants on which the fertilizer was intended to be used. Indeed, plants have different nutrient requirements at different growth stages. It is important to also note that the soil in which the plants are growing is also a factor to be considered when preparing the fertilizer mixture because different soils have different nutrient requirements depending on how nutrient-rich the soil is to begin with. Also because of the denitrifying nature and acidifying nature of nitrogen decomposition, the nutrient is the most susceptible to be lost during the process of decay. Therefore, in order to keep the level of nitrogen in the fertilizer sufficient for the plants it is vital to replace the nitrogen by adding urea or other nitrogen boosting compounds. Considering all the factors above, below is an averaged representation of the typical ratios for the fertilizer formulation specific for coffee production.

[0291] At planting stage:

[0292] • 70 kg Compost

[0293] • 6 kg Urea

[0294] • 10 kg Rock phosphorus + 2 Kg SSP (Single super Phosphate)

[0295] • 4 kg Volcanic Ash + 5 kg KCL (MOP; Potassium Chloride)

[0296] At vegetative stage:

[0297] • 70 kg Compost

[0298] • 10 kg Urea

[0299] • 10 kg Rock Phosphate + 2 kg SSP

[0300] • 3 kg Volcanic Ash + 5 kg KCL

[0301] At flowering and fruiting stage:

[0302] • 70 kg Compost • 7 kg Urea

[0303] • 6 kg Rock Phosphate + 2 kg SSP

[0304] • 10 kg Volcanic Ash + 5 kg KCL Total Organic Compost-NPK Ratio was therefore 70% Compost, 10% Nitrogen, 10% Phosphorus and 10% Potassium.

[0305] Since the biofertilizer contains both organic matter and a high nutrient content, the yield is expected to increase significantly. The yield is expected to increase between 20% - 25% for each harvest. The increase is measured from the average yield of a coffee tree in Uganda, where the experiment will take place, which is 0.6 kg. In Table 18, the expected increase in yield is calculated, for a 20% and 25% increase. It is expected that in a 4-year period the coffee production will reach around 2 kg per tree. After 2 years of biofertilizer application (including 5 harvest), the yield is expected to have increased by over 100 %. Unpredictable external factors such as floods or pest damages are not taken into account, although they can negatively impact the expected yield.

[0306] Table 18: Overview of the expected increase in yield:

[0307] In table 19 the expected increase in yield is calculated for the mean: 3.5 kg.

[0308] Table 19: Expected increase in yield: Example 13: Investigation of the effect of biofertilizer application on soil properties and coffee yields:

[0309] The study was conducted in an area in Uganda with tropical-savanna climate, in an area characterized by low rainfall, long dry spells and less fertile soils. This experiment was focused on mainly coffee grown under monoculture as a major cash crop grown. The biofertilizer, obtained using the technology according to example 1, was applied at different rates / ratios that is Control (without fertilizer), Treatment 1 (1.5 kg per tree) & Treatment 2 (3.0 Kg per tree) to three different stages of coffee i.e. Young (newly planted) and the Old (stumped) coffee received Organic NPK 4:7:4 mean while Mature / productive Coffee received the Organic NPK 7:4:4. The above treatments were subjected to 10 different trees each and treatments separated by a buffer coffee line where data was not collected, this was to minimize error. This was to monitor the impact of the biofertilizer on the coffee productivity at different stages of plant growth as well as determining the suitable application rate.

[0310] The experimental plot design was a Randomized Complete Block Design with the experimental plots randomly distributed among the three different districts with each plot being subjected to three treatments that is; Control (Co-OKg), Lower application rate (Tl- 1.5Kg) and the Higher application rate (T2-3.0Kg). For the three different stages of coffee that is: Young, Productive and Stumped coffee received the similar treatments above in the same season and were replicated as follows; Young and Stumped coffee three times each while Productive coffee was replicated six times. Every trial plot comprised of a total of 30 coffee trees with each treatment subjected to 10 coffee trees forming a block with a buffer line separating one treatment from another.

[0311] Soil data:

[0312] Soil analysis was carried out at the beginning of the project (before use of Organic NPK fertilizer) and a year after the establishment of the trial experiments (application of fertilizers). Different parameters were investigated: Organic carbon levels, soil pH, and Nutrient s (N, P, K). Other soil properties were also investigated: the soil temperature and moisture retention capacity. The findings obtained were as follows;

[0313] The soil temperature was measured at 30 cm depth and was ranging between 27-31 °C.

[0314] Soil parameters:

[0315] There was a significant difference in the soil pH realised after the application of the biofertilizer in comparison to the baseline pH level. The low Soil pH improved in most of the trial plots especially in the productive coffee from as low as 5.2 to 5.6- 6.0 in T1 and T2 respectively. The biofertilizer being 60 % organic matter could have contributed to the increase in soil pH due to its buffering capacity. Meanwhile amidst treatments; there was no significant difference between the control and the baseline soil pH instead it had the likelihood of getting low (acidity increase) whereas at T1 in comparison with control, the soil pH increased making it more suitable for nutrient availability and uptake for plant growth.

[0316] Initially the soil was generally infertile, acidic, high in clay content (Ferralsols), low pH at 5.3 and less Organic matter at 1.3 % below the critical level for tropics of 3 %. The biofertilizer was able to boost the nutrients as well as the physical and biological properties of the soil. It was able to raise the soil pH to a suitable level of 5.5 and above. The Organic carbon level improved though it was still below the recommended critical level especially in the stumped and young coffee. This could have been due to undeveloped tree canopy thus direct exposure of soil to the sun radiations that trigger oxidation of carbon to carbon dioxide. For nutrients like Nitrogen, during the baseline study, it was fairly good at 1.2g / Kg of soil which decreased to 1 g / Kg in the Control plot. It was maintained at 1.2 g / Kg at T1 plot and it slightly increased to 1.4 g / Kg at T2 plots. For Phosphorus, just as the Organic carbon, it remained below the critical level of 20 mg / kg but it was evident that addition of Organic fertilizer caused an increase from 7.7 mg / kg to 9.4 mg / kg at T1 and to 11.8 mg / kg at T2 which is a 22% and 53% increase respectively which is impressive, bearing in mind that this is a slow release nutrient.

[0317] Unlike all the above parameters which were initially low, potassium was high at the start of this experiment, but it greatly decreased in the Control and T1 meanwhile T2 had a slight increase by 16%. It is important to note that Potassium is not only a very mobile nutrient, it is also absorbed by plants as a luxury.

[0318] Plant health / Vigor and yield:

[0319] Addition of the biofertilizer facilitated good plant health by increasing the number of new twigs in the young and stumped coffee. The new clusters formed in the young coffee with fertilizer (T1 &T2) were more and closer to one another compared to those in the Control (without fertilizer). This would have an impact on the coffee yields afterwards. Meanwhile in the Productive coffee, there was a significant decrease in the number of trees affected by the Red blister disease (RBD) by 50 % with the use of the organic fertilizer whereby the in the control, 6 out of 10 trees had RBD compared to the plots with fertilizer i.e.; T1 &T2 with 3 out of 10 trees.

[0320] The coffee yield deteriorated in the plots where biofertilizer was not applied by 800 g / tree per harvest season while there was an increase observed in the plots where fertilizer was applied. At Tl, there was an increase of harvested coffee by 1.5 kg / tree while at T2 by 3 kg / tree per harvest season.

[0321] It is therefore recommended to use the biofertilizer at planting of coffee as a basal fertilizer and as a top dress to rejuvenate stumped and Productive coffee.

[0322] For Productive and Stumped coffee, it is recommended to apply 3 kg of the biofertilizer per tree per year as this seems to double the yields.

[0323] The biofertilizer was able to supplement not only nutrients but as well improve on the soil biological and physical health as stated in the above findings: it was able to improve on the soil pH, Organic carbon and nutrients.

[0324] Climate change can be mitigated by restoring carbon into the soil through the use of biofertilizers and ensuring maximum soil cover with minimum soil disturbance.

[0325] The impact of biofertilizer on the crop yields are long term and can be observed in the following harvest season after application because the nutrients are slowly released.

[0326] The biofertilizer being a slow release fertilizer with proper incorporation into the soil can reduce environmental pollution specifically Eutrophication of the surface waters.

[0327] Organic fertilizer being rich in micronutrients like Calcium and Magnesium was able to reduce coffee infestation with Red blister disease (RBD) by 50%. The application of 3kg / tree of the Organic fertilizer showed exceptional outcomes on the coffee yields. Considering the income levels of the small scale farmers, application of 1.5kg / tree of organic fertilizer per rain season would be recommended and they would be able to obtain the same high yields by the second harvest season and would as well reduce yield loss to RBD.

[0328] Example 14: Harvest data from demo gardens: The annual crops of Maize:

[0329] 6 cobs were collected from both the biofertilized and non biofertilized plots of a demo garden / demo hosts. These cobs were weighed and their weights taken. Then the maize seeds were removed from the cobs and weighed separately, so that the actual weight of the grain could be noted as shown in table 20.

[0330] Table 20: Yield (weight) of maize with or without fertilizer from 3 different demo hosts:

[0331] The results clearly shows that maize in biofertilized plots performed better than maize from non biofertilized plots. Example 15: Harvest data from demo gardens: The annual crops of Beans:

[0332] 10 dried bean plants were collected from both the biofertilized and non biofertilized plots of a demo garden. Then all the pods were removed and recorded separately. After complete drying, the pods were weighed and recorded. Then the bean seeds were removed from the pods and weighed separately and the actual weight of the bean seeds as seen notedin table Ff.

[0333] Table 21. Yield (weight) of beans with or without fertilizer from 2 different demo hosts

[0334] It can be seen that beans in biofertilized plots performed much better than beans from non biofertilized plots. Example 16: Efficacy in thermalization composting process in sterilization of coffee wilt disease and other pests in the husk.

[0335] The composting technology using the process disclosed in example 1 is used to document efficacy of the high-temperature composting process on: • Elimination of weed seeds and pathogens

[0336] • Suppression of Coffee wilt disease (CWD) and other plant diseases.

[0337] • Reduction of pest and parasite infections.

[0338] • Improvement of soil water retention and plant growth.

[0339] The experiment is a Completely Randomized Design (CRD) with at least 3 replicates, and comprises the following treatments:

[0340] • T1 -husk from local susceptible variety or inoculated prior to composting without thermalization;

[0341] • T2- husk from local susceptible variety or inoculated prior to composting using thermalization system;

[0342] • T3- husk from CWD resistant field or husk which is sanitized prior to composting without thermalization.

[0343] The experiment is monitored for a period of 2-4 weeks and is evaluated at 2, 3 and 4 weeks.

[0344] Parameters measured are:

[0345] • Nutrient content including organic carbon

[0346] • Live weed seeds

[0347] • Disease and pest incidence rates

[0348] • Other contaminants such as heavy metals.

[0349] Pathogen analysis is conducted using DNA / RNA sequencing on culture-based identification of CWD and fungal pathogens. Nutrient composition is evaluated for NPK, Ca, Mg, S, boron, Cu, Fe, Iodine, Mn, Zn and organic matter content, and microbial diversity using spectroscopy and culture technique as applicable.

[0350] Data is summarized and analyzed. Analysis of Variance and difference between means is conducted. Example 17: The amount of organic matter in compost and its effect on the moisture retention capacity in a field treated with the compost

[0351] The efficacy of the biofertilizer obtained in a process according to example 1 on field moisture retention is assessed.

[0352] The experiment is a Completely Randomized Design (CRD) comprising the following treatments:

[0353] • Tl- Compost applied at recommended application rate (according to the Uganda National Bureau of Standards);

[0354] • T2- Compost at half the recommended application rate (according to the Uganda National Bureau of Standards); and

[0355] • T3- Control (No compost)

[0356] The experiment is monitored for a period of 2 months preferable under irrigated system.

[0357] Parameters measured are:

[0358] • Moisture retention in soil following a known rate of irrigation water.

[0359] • Plant growth rate.

[0360] • Yield

[0361] Soil moisture retention is evaluated using gravimetric methods.

[0362] Example 18: Farmers experience regarding efficacy and user friendliness.

[0363] The farmers experiences using the biofertilizer obtained in a process according to example 1 is assessed.

[0364] The experiment is a Completely Randomized Design (CRD) comprising the following treatments:

[0365] Tl- Farmers trained during a dissemination meeting but not adopting the technology; • T2- Farmers trained during a dissemination meeting and using the technology; and

[0366] • T3- Control (neighbors who are not trained and do not use any compost technology).

[0367] The survey is conducted for 2 weeks.

[0368] Parameters measured are: • Nutrient content including organic carbon

[0369] • Moisture retention in soil capacity

[0370] • Plant growth rate / Yield

[0371] • Incidences of weeds.

[0372] • Incidences of coffee wilt disease and pests. • Incidences of contaminants such as heavy metals

[0373] Farmer observations and participatory assessments are done using on-farm visits based on a structured survey questionnaire and focus group discussions.

Claims

Claims1. A method for making organic fertilizer having a desired content of nutrients, such as N, P andK, by treating organic material in a container provided with means for air supply, means for temperature measurement and means for exhaust air comprising the steps of: a. Providing an organic starting material with an average particle size of < 20-40 mm b. Measuring the content of selected nutrients in the organic starting material c. Optionally adding 1 or more booster materials if the content of the selected nutrients is too low. d. Mixing and transferring the homogeneous organic starting material and any booster material to the container in an amount of 800 kg / m3 or less, e. Supplying air into the container to initiate a high heat composting process of the material in the container. f. Performing the composting, so the temperature exceeds a limit temperature of 70 C in a sufficient time for hygienization / sanitization of the organic material, g. Optionally adding nitrogen-fixing bacteria or enzymes while continuing air supply, for increase of N content. h. Discontinuing the air supply and removing the obtained organic fertilizer from the container i. Optionally measuring the content of selected nutrients in the organic fertilizer.

2. The method of claim 1, wherein the container is provided with: i. Means for supplying atmospheric air through the waste material ii. One or more sensors for measuring the temperature of the waste material, and iii. One or more sensors for measuring oxygen content within the waste material; iv. One or more outlets for exhaust air from the process3. The method of claim 1 or 2, wherein the organic starting material is selected among plant waste material such as coffee husks, avocado residual material, waste from rice, cereal, corn and cacao production, and waste from animal (manure), insect, or any organic residue from food manufacturing, hotels and resorts as well as sorted household and municipality organic waste including sludge from wastewater treatment.

4. The method according to any of the preceding claims, wherein the measurement of nutrients in the organic starting material includes measuring the content of N, P and K.

5. The method of claim 4, wherein the results of the measurements for N, P and K are compared to the desired content of nutrients6. The method of claim 5, wherein one or more booster materials are added if the measured content of N, P and / or K are / is below the desired content of N, P and / or K.

7. The method of claim 6, wherein the booster material to increase the N content is selected among manure in particular from poultry, water hyacinth, waste material from proteinaceous foods and sludge from waste water treatment facilities.

8. The method of claim 6, wherein the booster material to increase the P content is selected among manure in particular from feed stock, husks and mineral phosphates.

9. The method of claim 6, wherein the booster material to increase the K content is selected among ashes.

10. The method according to any of the preceding claims wherein hygienization / sanitization comprises maintaining the temperature in a range of 70-90 C for a period of at least 60 min.

11. The method according to any of the preceding claims, wherein the measurement of the organic fertilizer in step h includes measuring the content of N, P and K.

12. The method according to any of the preceding claims, wherein further nutrients are added.

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