Preparation method and application of straw granular fertilizer

Abstract

The invention belongs to the technical field of renewable resource utilization, and discloses a preparation method and application of a straw granular fertilizer. The preparation method comprises the steps of straw collection, straw stirring and melting, composting fermentation, secondary stirring and melting and extrusion granulation. According to the preparation method disclosed by the invention, a straw fibrosis treatment method is simplified, the efficiency is improved, straw field-leaving treatment is realized, and the pollution of straw combustion to the environment is reduced; waste gas, waste water and solid waste are not generated during straw treatment, the environment is not polluted, and the straw recycling, fertilizing and matrix utilization level can be improved. The prepared straw granulated fertilizer is rich in organic matter, contains N, P and K nutritional ingredients required by plant growth, can promote crop growth and increase the yield, and also can play a role in improving soil and improving soil fertility.

Description

Technical Field

[0001] The invention belongs to the technical field of renewable resource utilization, and in particular relates to a preparation method of straw granular fertilizer and application thereof. Background Art

[0002] Straw is a byproduct of crops and an important biological resource that can be comprehensively utilized. It can be used as fertilizer, feed, fuel for daily life, and raw materials for industrial and sideline production. my country is a large agricultural country with abundant straw resources, with an annual output of hundreds of millions of tons. The main ways to utilize agricultural straw resources are returning straw to the field (green manure), energy (biomass energy), raw material (used in construction, printing and other industries), feed, and base material. Fertilizer utilization, mainly returning straw to the field, has become the main channel for straw utilization. However, in actual production, straw is large in volume, difficult to utilize, and has a low fertilizer utilization rate. Due to excessive turning over, insufficient soil moisture, insufficient nitrogen fertilizer supplementation, and poor turning over quality, it often hinders farming, affects seedling emergence, burns seedlings, and increases pests and diseases. In severe cases, it will also cause a reduction in the yield of subsequent crops. Due to factors such as the scattered distribution of resources, large areas, difficult storage, and high cost of returning to the field, the comprehensive utilization level of straw is not high. In some areas, open-air burning of straw still exists, causing air pollution and other problems.

[0003] The first prerequisite for all of the above-mentioned resource utilization methods is that straw is crushed. The crushing process for crop straw resource utilization is generally to use a grass cutter to chop it and then pile it up for fermentation, or to directly pile up the straw for fermentation. Due to the complexity of the substances contained in the straw, in terms of industrial utilization, it is not a simple matter of crushing or cutting it, stirring it evenly, adding certain chemical products, and then extruding or pressing it to produce a product. At present, the commonly used industrial equipment for straw crushing includes feed grinders and kneading machines, and the crushed straw still has the defect of low resource utilization efficiency. In addition, due to the difficulty in straw utilization and the low fertilizer utilization rate, in the prior art, when straw is applied as a fertilizer, other fertilizers or inorganic nutrients are often added to meet the growth needs of plants.

[0004] Therefore, it is very important to explore a method for preparing straw pellet fertilizer that can improve straw composting efficiency, increase straw utilization rate, and facilitate mechanized production and application, so that the prepared straw pellet fertilizer can promote crop growth and increase yield without the need for additional inorganic nutrients. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing straw pellet fertilizer, which simplifies the straw fiberization treatment method, improves the composting efficiency, and facilitates mechanized production and application. The prepared straw pellet fertilizer has rich organic matter, does not require additional inorganic nutrients, can promote crop growth and increase yield, and can also improve soil and enhance soil fertility.

[0006] Another object of the present invention is to provide a straw granule fertilizer and its application in promoting crop growth and increasing crop yield.

[0007] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0008] The present invention provides a preparation method of a straw granule fertilizer, comprising the following steps:

[0009] Harvest straw, stir and melt the straw, add a fermentation inoculant during the stirring and melting process to obtain fibrillated straw; stack and ferment the fibrillated straw to obtain a matured material; perform secondary stirring and melting treatment on the matured material and extrude into granules.

[0010] Preferably, the straw includes any one or more of rice, corn, and wheat.

[0011] Preferably, the fermentation inoculant includes one or more of RW enzyme agent, ditch and pond bottom mud, or paddy field soil.

[0012] Preferably, based on the weight of the straw, the dosage of the RW enzyme agent is 0.5 - 1.5 kg / ton, and the dosage of the ditch and pond bottom mud or paddy field soil is 40 - 60 kg / ton.

[0013] Preferably, the time for the stirring and melting treatment of the straw is 30 - 50 min.

[0014] Preferably, the stacking and fermentation process includes turning the pile once after natural fermentation for 25 - 35 days and then fermenting for another 10 - 15 days.

[0015] Preferably, the water content during the stacking and fermentation process is controlled at 30 - 40%.

[0016] Preferably, the time for the secondary stirring and melting treatment is 10 - 30 min.

[0017] The present invention also provides a straw granule fertilizer prepared by the above preparation method.

[0018] The present invention also provides the application of the above straw granule fertilizer in promoting crop growth and increasing crop yield.

[0019] Advantages of the present invention:

[0020] After the crop straws of the present invention are collected, they directly enter the mechanical flow operation without going through sun drying or drying, reducing the operation steps of straw treatment and lowering the energy consumption and labor costs; the crop straw fiberization treatment technology of the present invention is conducive to killing harmful microorganisms in the straws, increasing the number of decay-promoting bacteria, shortening the process of straw decay and temperature rise, and improving the decay efficiency; no waste gas, waste water or solid waste is generated during the treatment process of the present invention, and the environment is not polluted; after granulation, the straw fertilizers are convenient for mechanical application, reducing the labor costs and improving the labor efficiency. At the same time, the straw pellet fertilizers prepared by the present invention have simple raw materials, rich organic matter, contain N, P, K nutrient components required for plant growth, do not require additional addition of inorganic nutrients, can promote crop growth and increase the yield, and can also play a role in improving the soil and enhancing the soil fertility.

[0021] The preparation method of the straw pellet fertilizer of the present invention simplifies the straw fiberization treatment method, improves the efficiency, is suitable for pipeline operation, scale and commercialization, and provides convenience for subsequent utilization such as resourceization, fertilization and matrix formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The influence of adding different fermentation inoculants on the temperature change during the straw composting process;

[0023] Figure 2 The morphological characteristics of different straw treatment methods, where the upper figure is the straw stirring and melting treatment, the left figure in the upper figure is the baled straw, the middle figure is the fiberized straw after straw stirring and melting treatment, and the right figure is the matured material after composting fermentation; the lower figure is the straw crushing treatment, the left figure in the lower figure is the crushed rice straw, the middle figure is the crushed wheat straw, and the right figure is the crushed corn straw;

[0024] Figure 3 The morphological characteristics of different straw treatment methods, where the left figure is the material after the rice straw is stirred and melted, and the right figure is the material after the fresh rice straw is crushed;

[0025] Figure 4 The influence of the stirring and melting treatment on the change of the number of fungi and bacteria carried by the straw;

[0026] Figure 5 The rice straw pellet fertilizer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention provides a preparation method of a straw pellet fertilizer, comprising the following steps:

[0028] Harvest the straws, perform a stirring and melting treatment on the straws, and add a fermentation inoculant during the stirring and melting process to obtain fiberized straws; perform composting fermentation on the fiberized straws to obtain matured materials; perform a secondary stirring and melting treatment on the matured materials and extrude and granulate them.

[0029] In the present invention, the straw can be selected from crop straws commonly used in the field for preparing organic fertilizers, preferably including any one or several of rice, corn, and wheat, and more preferably rice straw. After the straw is harvested, a feed (grass) harvesting machine (such as a straw pick-up baler, a straw baler, etc.) can be used to collect and bale the straw, which is then stacked at the edge of the field or along the tractor path for standby use. There is no special limit on the stacking time. After the crop straw is collected, it directly enters the mechanical flow operation without going through drying or baking, reducing the operation steps of straw treatment and lowering the energy consumption and labor cost.

[0030] In the present invention, the fermentation inoculant can be selected from fermentation inoculants commonly used in the field. Preferably, the fermentation inoculant includes one or several of RW enzyme agent, ditch pond bottom mud, or paddy field soil. The ditch pond bottom mud is one or a mixture of paddy field ditches and fish pond bottom mud, which is dug and stacked for draining and standby use during dredging; the paddy field soil is dug after rice harvest. The ditch pond bottom mud and the paddy field soil can be used alone or mixed in a certain mass ratio, such as a mass ratio of 1:1. Based on the weight of the straw, the dosage of the RW enzyme agent is 0.5 - 1.5 kg / ton, and the dosage of the ditch pond bottom mud or the paddy field soil is 40 - 60 kg / ton; preferably, the dosage of the RW enzyme agent is 0.75 - 1.25 kg / ton, and the dosage of the ditch pond bottom mud or the paddy field soil is 45 - 55 kg / ton; more preferably, the dosage of the RW enzyme agent is 1 kg / ton, and the dosage of the ditch pond bottom mud or the paddy field soil is 50 kg / ton. The effective viable count in the fermentation inoculant is preferably above 5 billion cfu / g. The stirring and melting treatment can use a mature straw stacking, pressing, stirring, and melting machine on the market. The time for the straw stirring and melting treatment is 30 - 50 min, preferably 35 - 45 min, and more preferably 40 min. The fermentation inoculant is added 20 - 40 min after the start of the straw stirring and melting treatment, preferably 25 - 35 min, and more preferably 30 min. After the crop straw is cut, torn, stirred, and rubbed by the stacking, pressing, stirring, and melting machine, more than 80% of the straw becomes flocculent short fibers, realizing the fiberization and reduction of the straw, without generating waste gas, waste water, and solid waste, and without polluting the environment; after 10 minutes of stirring and melting, the viable count of fungi in the straw significantly decreases, and the number of bacteria shows an exponential increase 30 minutes after the treatment (the reason is that a large amount of nutrients are released after the straw is broken, providing suitable nutrients and environment for the heat-resistant bacteria carried in the straw, enabling their numbers to rise rapidly), which is beneficial to killing harmful microorganisms in the straw and increasing the number of decay-promoting bacteria, providing conditions for rapid decomposition.

[0031] In the present invention, a conveyor belt can be used to transport the fibered straw to a transport vehicle or a tipping truck and then to a composting site. The composting height is 1.5 - 2 meters, or the composting height can be adjusted according to the actual situation. The composting fermentation process includes turning the pile once after natural fermentation for 25 - 35 days, then fermenting for another 10 - 15 days, and controlling the water content at 30 - 40%; preferably, turning the pile once after natural fermentation for 30 days, then fermenting for another 10 - 15 days, and controlling the water content at 30 - 40%. The moisture of the granulated material can be controlled by adding water or increasing the frequency of turning the pile. Since fermentation inoculants are added during the straw fiberization process, the composting fermentation process can utilize the finished fermentation inoculants or the indigenous probiotics inherent in the bottom mud of ditches or ponds or the soil of paddy fields to promote the decomposition of straw. Among them, the indigenous probiotics are local adaptable probiotic populations with good growth advantages; by using the heat generated during the stirring and friction process, the temperature-rising process of straw decomposition can also be shortened (the temperature rises above 60 °C after 1 day), improving the decomposition efficiency; the flocculent straw fibers can promote the material transformation during the fermentation process, shorten the fermentation time, and improve the fertilizer efficiency.

[0032] In the present invention, the decomposed material is subjected to stirring and melting treatment again. The stirring and melting time is 10 - 30 min, preferably 15 - 25 min, and more preferably 20 min. After being stirred and melted by a stacking and stirring and melting machine, the decomposed material is broken into small granular shapes, becoming high-quality raw materials for straw organic fertilizers.

[0033] In the present invention, for the extrusion granulation, a mature biomass granulator or feed granulator on the market can be used to roll press (extrude) the material after the second stirring and melting through a die hole roller press. The present invention has no special limitation on the particle shape after granulation, and bar-shaped particles are preferred. As an implementable way, the particle size of the straw granule fertilizer is 10 mm - 20 mm in length and 8 mm - 10 mm in diameter, preferably 15 mm in length and 9 mm in diameter. After granulation, it is convenient for mechanized application, reducing the labor cost and improving the labor efficiency.

[0034] The present invention also provides a straw granule fertilizer prepared by the above preparation method.

[0035] The present invention also provides the application of the above straw granule fertilizer in promoting crop growth and increasing crop yield.

[0036] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0037] In the following embodiments, unless otherwise specified, all are conventional methods.

[0038] In the following embodiments, the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0039] The forage (grass) harvesting machine used in the following examples was the YF-1.6 straw pick-up baler. The stacking, pressing, stirring and melting machine was the "ZHD-5 horizontal stirring and melting machine" produced by Qingdao Zhonghengda Machinery Co., Ltd. The granulator was the "250 type energy-saving and high-efficiency feed granulator" produced by Zhangqiu Xiuhui Ruide Machinery Factory.

[0040] The Rujin probiotics used in the following examples were purchased from Kangyuan Oasis Biotechnology (Beijing) Co., Ltd. The RW enzyme agent was purchased from Hebi Renyuan Biotechnology Development Co., Ltd. The Qunlin fermentation agent was purchased from Beihai Qunlin Biological Engineering Co., Ltd.

[0041] Example 1

[0042] A preparation method of straw granular fertilizer includes the following steps:

[0043] After the rice straw is harvested, use the forage (grass) harvesting machine to collect and bale the straw, stack it for standby, with the water content being 20% - 80%; convey the straw to the stacking, pressing, stirring and melting machine for stirring, melting and pulverizing, with the stirring and melting time being 40 min. Add 1 kg of RW enzyme agent per ton of straw after stirring and melting for 30 min, and pulverize (fibrize) it into flocculent materials, with the water content controlled at 50% - 70%; stack and ferment the fibrillated straw, turn the pile once after 30 days, and ferment for another 15 days, with the water content controlled at 30% - 40% to obtain the matured materials; perform the stirring and melting treatment on the matured materials again for 20 min; convey it to the granulator for rolling and granulation.

[0044] Example 2

[0045] Add 50 kg of paddy field soil per ton of straw, and the other steps are the same as in Example 1.

[0046] Example 3

[0047] Add 50 kg of ditch and pond bottom mud per ton of straw, and the other steps are the same as in Example 1.

[0048] Example 4

[0049] Add 25 kg of paddy field soil and 25 kg of ditch and pond bottom mud per ton of straw, and the other steps are the same as in Example 1.

[0050] Example 5

[0051] Change the first straw stirring and melting treatment time in Example 1 to 30 min, add 1 kg of RW enzyme agent per ton of straw after stirring and melting for 20 min, and the other steps are the same as in Example 1.

[0052] Example 6

[0053] Change the first straw stirring and melting treatment time in Example 1 to 50 min, add 1 kg of RW enzyme agent per ton of straw after stirring and melting for 40 min, and the other steps are the same as in Example 1.

[0054] Example 7

[0055] A preparation method of straw granular fertilizer, comprising the following steps:

[0056] After the rice straw is harvested, use a forage (grass) harvesting machine to collect and bale the straw, stack it for standby, with a water content of 20% - 80%; the straw is subjected to stirring and melting and pulverizing by a stacking and pressing stirring and melting machine, and the stirring and melting time is 50 min. After stirring and melting for 30 min, add 50 kg of paddy field soil per ton of straw, and pulverize (fibrize) it into flocculent materials, with the water content controlled at 50% - 70%; stack and ferment the fibrillated straw, turn the pile once after 30 days, and ferment for another 10 days, with the water content controlled at 30% - 40% to obtain matured materials; perform stirring and melting treatment on the matured materials for 20 min; convey them to a granulator for roll granulation.

[0057] Example 8

[0058] A preparation method of straw granular fertilizer, comprising the following steps:

[0059] After the rice straw is harvested, use a forage (grass) harvesting machine to collect and bale the straw, stack it for standby, with a water content of 20% - 80%; the straw is subjected to stirring and melting and pulverizing by a stacking and pressing stirring and melting machine, and the stirring and melting time is 50 min. After stirring and melting for 30 min, add 1 kg of RW enzyme agent per ton of straw, and pulverize (fibrize) it into flocculent materials, with the water content controlled at 50% - 70%; stack and ferment the fibrillated straw, turn the pile once after 30 days, and ferment for another 10 days, with the water content controlled at 30% - 40% to obtain matured materials; perform stirring and melting treatment on the matured materials for 20 min; convey them to a granulator for roll granulation.

[0060] Comparative Example 1

[0061] Add 1 kg of Rujin probiotics per ton of straw, and the other steps are the same as in Example 1.

[0062] Comparative Example 2

[0063] Add 1 kg of Qunlin fermenting agent per ton of straw, and the other steps are the same as in Example 1.

[0064] Comparative Example 3

[0065] Do not add fermenting agent, and the other steps are the same as in Example 1.

[0066] Comparative Example 4

[0067] In Example 1, the straw is not subjected to stirring and melting treatment, but is pulverized using an RC-8 straw pulverizing and rubbing machine, and the other steps are the same as in Example 1.

[0068] Comparative Example 5

[0069] Change the first straw stirring and melting treatment time in Example 1 to 20 min, add 1 kg of RW enzyme agent per ton of straw after stirring and melting for 10 min, and the remaining steps are the same as in Example 1.

[0070] Comparative Example 6

[0071] Change the first straw stirring and melting treatment time in Example 1 to 60 min, add 1 kg of RW enzyme agent per ton of straw after stirring and melting for 50 min, and the remaining steps are the same as in Example 1.

[0072] Test Example 1 Influence of Different Fermentation Bacterial Agents on Straw Composting Temperature

[0073] 1.1 Test Method

[0074] Test site: Production base of Huli Grain and Oil Cooperative in Yushan Township, Fuyang District.

[0075] Test grouping: Four fermentation bacterial agents were added respectively in the test for straw fiberization treatment to compare the effects of the composting temperature of the materials, namely Rujin probiotics (about 20 billion viable bacteria / ml) (prepared by the method of Comparative Example 1), RW enzyme agent (more than 5 billion viable bacteria / gram) (prepared by the method of Example 1), Qunlin fermentation agent (more than 8 billion viable bacteria / gram) (prepared by the method of Comparative Example 2), and self-made indigenous probiotics (mixture of local fish pond bottom mud and paddy field soil (1:1), using its own indigenous probiotics, more than 5 billion viable bacteria / gram, prepared by the method of Example 4). The control CK was without adding fermentation bacterial agent (prepared by the method of Comparative Example 3).

[0076] Record the temperature changes during the composting fermentation process of each group respectively, and measure the time required for the composting fermentation temperature to reach 60 °C, the duration at 60 °C, the highest temperature of the composting fermentation, and the duration of the highest temperature in different treatment groups respectively.

[0077] 1.2 Result Analysis

[0078] The results are as Figure 1As shown in Table 1. Compared with the control, under the treatment of four kinds of fermentation inoculants, the temperature of straw fiber compost increased rapidly, reached a higher maximum temperature, and the high-temperature duration was longer. Comparing the four kinds of fermentation inoculants, the temperature increased fastest under the treatment of RW enzyme agent, reaching 60 °C in only 1 day, and the high-temperature duration above 60 °C was the longest, reaching 26 days. It also only took 1 day for the self-made indigenous probiotics treatment to reach the highest temperature, but the highest temperature reached was slightly lower than that of the RW enzyme agent; followed by Rujin probiotics and Qunlin fermenter, and high temperatures above 60 °C also continuously appeared during the whole composting process, but the effects such as the time to reach high temperature and the duration at 60 °C were slightly worse than those of the RW enzyme agent and the self-made indigenous probiotics. Thus, it can be seen that during the straw fiber fermentation process, the use of different fermentation inoculants has a great impact on temperature changes, and with different added inoculants, the temperature of straw compost also shows different changing trends.

[0079] Table 1 Temperature change characteristics in straw compost inoculated with different fermentation inoculants

[0080]

[0081] It can be seen that after adding the RW fermenter, the temperature of straw compost increased fastest, and the high-temperature duration was also long, which could effectively decompose the organic matter in the compost and shorten the time to reach maturity. During the straw fiber treatment process, paddy field soil and fish pond bottom mud were added, and the indigenous probiotics inherent in the soil and bottom mud were used to promote the decomposition of straw. The indigenous probiotics were the local suitable probiotic groups and had good growth advantages. The self-made indigenous probiotics had low cost, were convenient for material collection and use. After adding, the temperature of straw compost increased relatively fast. Especially after adding fish pond bottom mud or paddy field soil, the density of the fiberized straw materials was increased, which was conducive to adjusting the fermentation moisture of the materials and promoting the decomposition of straw. It was also a kind of decay-promoting agent suitable for fiberized straw compost.

[0082] Test Example 2 Effects of different treatment methods on the decomposition effect of straw

[0083] 2.1 Test method

[0084] Test site: Production base of Huli Grain and Oil Cooperative in Yushan Township, Fuyang District.

[0085] The straw was treated by a stacking, pressing, stirring and melting machine and an RC-8 straw crushing and rolling machine respectively. After the stirring and melting machine stirred and melted for 40 minutes, the material was discharged for composting, and the crusher directly discharged the material for composting, and no decay-promoting agent was added.

[0086] 2.2 Result analysis

[0087] 2.2.1 Morphological characteristics of different treatment methods of straw

[0088] The results are as Figure 2 、 Figure 3As shown in the figure. Through the cutting, tearing, stirring and friction of the crop straw by the stacking and stirring machine, more than 80% of the straw becomes flocculent short fibers. The main components on the surface, namely lignin and hemicellulose, are partially removed and degraded, resulting in the exposure of the underlying internal structure, which is conducive to accelerating the composting process and realizing the fiberization and reduction of straw. However, the straw crushed by the straw crushing and silk rubbing machine only shortens the length of the straw and becomes granular, with a hard and rough texture, which is not conducive to the composting process.

[0089] 2.2.2 Composting characteristics of different straw treatment methods

[0090] During the straw fiberization process, the heat generated during the auger stirring and friction shortens the straw composting temperature rising process (the temperature rises above 60 °C after 1 day), improving the composting efficiency; the flocculent straw fibers can promote the material conversion during the fermentation process, shorten the fermentation time, and improve the fertilizer efficiency. Tests show that the core temperature of the fibrous straw compost reaches about 62 °C after 24 h of composting, while the core temperature of the crushed straw compost can only reach about 55 °C after 24 h of composting. It can be seen that the stirring treatment has a good effect on promoting straw composting.

[0091] 2.2.3 Influence of stirring treatment on the change of the number of microorganisms carried by straw

[0092] The results are as Figure 4 shown in the figure. Through the cutting, tearing, stirring and friction of the crop straw by the stacking and stirring machine, more than 80% of the straw becomes flocculent short fibers, realizing the fiberization and reduction of straw. After stirring for 10 minutes, the viable fungal count in the straw decreases significantly, and the number of bacteria shows an exponential surge after 30 minutes of treatment (the reason is that a large amount of nutrients are released after the straw is broken, providing suitable nutrients and environment for the heat-resistant bacteria carried in the straw, enabling their numbers to rise rapidly), which is conducive to killing harmful microorganisms in the straw and increasing the number of compost-promoting bacteria, providing conditions for rapid composting.

[0093] Experimental Example 3 Influence of different stirring times on the composting effect of straw

[0094] 3.1 Experimental method

[0095] Experimental site: The production base of Huli Grain and Oil Cooperative in Yushan Township, Fuyang District.

[0096] Experimental process: According to different stirring times during the straw stirring process, 5 treatments were set, namely 20 min, 30 min, 40 min, 50 min, and 60 min. Referring to the preparation methods of Comparative Example 5, Example 5, Example 1, Example 6, and Comparative Example 6 respectively, straw granular fertilizers were prepared, and the bulk density of fibrous straw, the core temperature after 24 h, and the energy consumption efficiency of each treatment group were measured respectively.

[0097] 3.2 Result analysis

[0098] The results are shown in Table 2. The bulk density of the fibered straw of different materials increases with the prolongation of the stirring and melting time. After composting for 24 h, the core temperature of the compost increases with the prolongation of the stirring and melting time, and the bulk density of the straw and the core temperature of the compost after 24 h of composting reach relative stability when the stirring and melting time is 40 min. Considering the energy consumption efficiency at different times, the optimal stirring and melting time is preferably 40 min.

[0099] Table 2 Test results of the stirring and melting fibrosis of rice straw

[0100]

[0101] Test Example 4 Application test of straw granule fertilizer in dry land

[0102] 4.1 Materials and methods

[0103] 4.1.1 Tested soil

[0104] The test plot is located in Nanshan Village, Pingyao Town, Yuhang District, Hangzhou City, at the Hangzhou Manshanhong Fruit and Vegetable Professional Cooperative. The soil at the test site is muddy sand paddy field, with a texture of clay loam. The physical and chemical properties of the soil before the test are as follows: pH 4.42, organic matter 32.2 g / kg, total N 0.241%, available phosphorus 396.5 mg / kg, available potassium 427 mg / kg.

[0105] 4.1.2 Types of fertilizers

[0106] The straw granule fertilizer made from rice straw is processed by Wang Yunfeng Family Farm in Daicun, Xiaoshan, and is prepared by the preparation method of Example 1. The prepared rice straw granule fertilizer has an organic matter content of 65.3%, a pH value of 8.5, total nitrogen (N) 1.77%, phosphorus (P2O5) 1.28%, and potassium (K2O) 2.07%.

[0107] The commercial organic fertilizer is produced by Hangzhou Greenbao Organic Chemical Fertilizer Co., Ltd. (Yuhang), with an organic matter content of 38.6%, a pH value of 8.4, total nitrogen (N) 1.70%, phosphorus (P2O5) 2.66%, and potassium (K2O) 1.79%.

[0108] 4.1.3 Test design

[0109] Five treatments are set, namely, applying 250 kg, 500 kg, and 750 kg of straw granule fertilizer as base fertilizer per mu before transplanting Chinese cabbage, 300 kg of commercial organic fertilizer, and using no base fertilizer as the control. According to the field plot test design, each treatment has one plot with an area of 20 m 2, Randomly arranged, repeated three times. The crop is green vegetables, the variety is Shanghaiqing, and the previous crop is leafy vegetables. Except for the amount of base fertilizer applied, other field management measures are the same for different treatments. The straw pellet fertilizer and organic fertilizer are applied as base fertilizer at one time and plowed after application; the chemical fertilizer is applied as topdressing after the green vegetables are transplanted. The application amounts of N, P, and K in the chemical fertilizer are determined according to the soil testing and formulated fertilization technology and combined with the requirements of the chemical fertilizer quota for green vegetables.

[0110] When collecting plants in each plot, soil (5 - 20 cm) is collected at the same time, and the organic matter content is determined by the external heating method of potassium dichromate oxidation.

[0111] 4.2 Result Analysis

[0112] 4.2.1 Influence of Base Fertilizer Application on Green Vegetable Production

[0113] (1) Influence of base fertilizer application on green vegetable yield:

[0114] The results are shown in Table 3. Compared with the control without applying organic fertilizer, the treatments with organic fertilizer as base fertilizer all showed a certain yield increase effect, with the yield increase range of 73.8 kg / mu - 178.2 kg / mu and the increase rate of 4.21% - 10.15%. Especially the treatment (T3) with 750 kg of straw pellet fertilizer applied per mu had the most obvious yield increase, with a 10.15% increase compared to the blank control. It can be seen that applying 750 kg of straw fertilizer per mu as base fertilizer before transplanting green vegetables is beneficial to green vegetable production and can increase crop yield.

[0115] (2) Influence of base fertilizer application on the plant traits of green vegetables:

[0116] The results are shown in Table 3. Compared with the control without applying organic fertilizer, the single-plant weight of green vegetables showed a certain positive effect in the treatments with organic fertilizer as base fertilizer, and the increase rate of plant height was 7.70% - 27.90%. Especially the treatment (T3) with 750 kg of straw pellet fertilizer applied per mu had the most obvious increase rate, and the single-plant weight increased by 27.87% compared to the blank control. Except for a slight decrease in the treatment with 250 kg of straw pellet fertilizer applied per mu, the average single-plant height in other treatments also had a certain increase rate, among which the increase rate of the treatment with 750 kg of straw pellet fertilizer applied per mu was 8.47%. It can be seen that applying 750 kg of straw pellet fertilizer per mu as base fertilizer before transplanting green vegetables is beneficial to green vegetable production and can increase crop yield.

[0117] Table 3 Influence of Base Fertilizer Application on the Plant Traits and Yield of Green Vegetables

[0118] Treatment group Base fertilizer treatment Single plant weight (g) Single plant height (cm) Yield per mu (kg) T1 250 kg of straw granule fertilizer 125.5±36.6 23.8±2.7 1860.4 ± 171.5 ab T2 500 kg of straw granule fertilizer 135.8±30.0 26.1±0.8 1886.4 ± 76.0 ab T3 750 kg of straw granule fertilizer 149.0±16.2 26.9±1.5 1934.1±104.0a T4 300 kg of commercial organic fertilizer 136.9±13.1 24.9±1.7 1829.8 ± 109.9 ab T5 No base fertilizer applied 116.5±7.7 24.8±0.3 1755.9±68.5b

[0119] Note: Different lowercase letters in the same column indicate significant differences between different treatments (P < 0.05).

[0120] 4.2.2 Influence of Base Fertilizer Application on the Physical and Chemical Properties of Soil

[0121] After different basal fertilizer treatments, the data of the physical and chemical properties of the green vegetable field soil are shown in Table 4. Generally speaking, applying straw granule fertilizer and commercial organic fertilizer as basal fertilizers before transplanting green vegetables can increase the soil pH value, organic matter, total nitrogen and humus, playing a role in improving the soil and enhancing soil fertility. Due to the relatively high annual fertilization level in vegetable fields, available phosphorus and available potassium are relatively abundant. Therefore, different fertilization types and application rates have little effect on the changes in soil phosphorus and potassium after single-season green vegetable cultivation.

[0122] Table 4 Physical and Chemical Properties of Soil under Different Basal Fertilizer Treatments

[0123]

[0124] The straw granule fertilizer prepared from rice straw is rich in organic matter and contains the N, P, and K nutrient components required for plant growth, especially a relatively high potassium content, which can supplement the growth of crops in vegetable fields, playing a role in reducing the use of chemical fertilizers and promoting crop growth. Through the dryland application experiment of straw granule fertilizer, the influence of straw granule fertilizer on the physical and chemical properties of the soil was initially clarified, indicating that the straw granule fertilizer has a soil fertility improvement effect, which can increase the soil pH value, organic matter, total nitrogen and humus, playing a role in improving the soil and enhancing soil fertility.

[0125] Field experiments show that the fertilization mode of applying 750 kg of straw granule fertilizer per mu as basal fertilizer can achieve relatively stable crop yields on the basis of reducing chemical fertilizers, having a good effect of reducing chemical fertilizers and increasing efficiency, which is worthy of production promotion and application.

[0126] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing straw granular fertilizer, characterized in that, It includes the following steps: Harvest the straw, subject the straw to stirring and melting treatment, add a fermentation inoculant during the stirring and melting process to obtain fibrous straw; perform composting fermentation on the fibrous straw to obtain a matured material; subject the matured material to secondary stirring and melting treatment and extrusion granulation.

2. The preparation method according to claim 1, characterized in that, The straw includes any one or several of rice, corn, and wheat.

3. The preparation method according to claim 1, wherein The fermentation inoculant includes one or several of RW enzyme agent, ditch pond bottom mud, or paddy field soil.

4. The preparation method according to claim 3, characterized in that, Based on the weight of the straw, the dosage of the RW enzyme agent is 0.5 - 1.5 kg / ton, and the dosage of the ditch pond bottom mud or paddy field soil is 40 - 60 kg / ton.

5. The preparation method according to claim 1, wherein The time for the stirring and melting treatment of the straw is 30 - 50 min.

6. The preparation method according to claim 1, characterized in that, The composting fermentation process includes turning the pile once after natural fermentation for 25 - 35 days and then fermenting for another 10 - 15 days.

7. The preparation method according to claim 6, wherein During the composting fermentation process, the water content is controlled at 30 - 40%.

8. The preparation method according to claim 1, wherein The time for the secondary stirring and melting treatment is 10 - 30 min.

9. The straw granule fertilizer prepared by the preparation method according to any one of claims 1 - 8.

10. The application of the straw granule fertilizer according to claim 9 in promoting crop growth and increasing crop yield.

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