Seedling raising substrate based on rice straws and biogas residues as well as preparation method and application of seedling raising substrate

Abstract

The invention provides a rice straw and biogas residue-based seedling raising substrate and a preparation method thereof, the substrate is composed of a basic raw material and an additive, the basic raw material comprises, by weight, 50% of decomposed rice straw, 20% of biogas residue and 30% of vermiculite, and the additive is an additive; the additive is prepared by adding 1% of ferrous sulfate, 1% of calcium superphosphate, 1% of ammonium sulfate and 0.5% of amino acid fertilizer according to the total weight of the basic raw materials. According to the seedling raising substrate, the content of alkali-hydrolyzable nitrogen is 1204 mg / kg, the content of available phosphorus is 730 mg / kg, the content of available potassium is 2841 mg / kg, the pH value is 7.19, the conductivity is 3.23 mS / cm, the total porosity is 82%, the volume weight is 0.30 g / cm < 3 >, the seedling raising substrate can be suitable for mechanical transplanting seedling raising of rice, the seedling quality is high, the seedling slowing capacity is high, the seedling raising cost is low, the resource utilization process of rice straw and biogas residues can be promoted, environmental pollution is reduced, and the economic benefit is increased. And the method also has better economic, ecological and social benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of straw, and in particular relates to a rice straw and biogas residue-based seedling raising substrate, and a preparation method and application thereof. Background Art

[0002] Caofeidian District is located in the central area of ​​the Bohai Sea Rim and belongs to the Tangqin coastal saline-alkali area of ​​eastern Hebei. It is the main rice producing area in Hebei Province, with a rice planting area of ​​about 320,000 mu. It requires about 9.6 million 9-inch machine-transplanted seedlings each year, and produces about 250,000 tons of straw after harvest. According to investigations and visits, some farmers use natural soil and seedling-strengthening agents to mix and make homemade nutrient soil for seedling cultivation, while seedling cooperatives purchase seedling cultivation substrates from other places. It is difficult to uniformly cultivate high-quality machine-transplanted seedlings on a large scale with homemade nutrient soil, which directly causes the uneven quality of machine-transplanted seedlings. In addition, natural soil resources are limited, and long-term uncontrolled excavation will damage the ecosystem. Although purchasing seedling cultivation substrates from other places can cultivate high-quality seedlings, the transportation cost and difficulty are high, which increases the cost of seedling cultivation and may delay the progress of farming. Therefore, the development of a localized, low-cost, and environmentally friendly rice machine-transplanted seedling cultivation substrate is an urgent task for the district.

[0003] Rice straw is rich in nutrients such as nitrogen, phosphorus and potassium, and is an important organic resource. Biogas residue is a biological fermentation product produced by anaerobic fermentation of organic matter such as livestock and poultry manure. It contains a large amount of humic acid, organic matter, and nutrients such as nitrogen, phosphorus and potassium. Both decomposed straw and biogas residue are agricultural solid wastes, and both are rich in nutrients. However, the structure of straw raw materials is complex. Its main components are cellulose, hemicellulose and lignin, and the three form a compact crystal structure in space, which affects their biodegradability, resulting in low degradation rate of fermentation raw materials, slow fermentation start-up, long fermentation time and other problems. At the same time, due to the low temperature in autumn and winter in the rice-growing areas of eastern Hebei, specific low-temperature-resistant microorganisms are required to quickly start composting under low temperature conditions. If the local rice straw and sludge are properly disposed of to develop a medium for rice machine-transplanted seedlings, it will not only solve the problems of large amounts of homemade nutrient soil, difficulty in obtaining soil, and serious damage to the plow layer, but also increase the high-value utilization of straw, solve the problem of idle agricultural waste from factories around Caofeidian, save the cost of rice seedling production, and realize the recycling of waste in rice production. It will have good economic, ecological and social benefits and be conducive to the sustainable development of agriculture. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a rice seedling raising substrate based on rice straw and biogas residue and a preparation method and application thereof in view of the deficiencies of the above-mentioned prior art. The present invention screens the mixing ratio of the basic raw materials of the rice seedling raising substrate, screens the acidifier, screens the nutrient element fertilizer, and performs field verification tests, and finally develops a rice machine-transplanted seedling raising substrate formula using agricultural waste such as decomposed rice straw and biogas residue.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A rice straw and biogas residue-based seedling raising substrate, the rice straw and biogas residue-based seedling raising substrate consisting of basic raw materials and additives, the basic raw materials comprising 30-80% of decomposed rice straw, 10-30% of biogas residue and 10-50% of vermiculite in weight ratio, the additives comprising 1-5% of ferrous sulfate, 0.5-5% of superphosphate, 0-5% of ammonium bicarbonate, 0-5% of monoammonium phosphate, 0.5-5% of ammonium sulfate and 0.5-2% of amino acid fertilizer in accordance with the total weight of the basic raw materials.

[0007] Preferably, the seedling raising matrix is ​​composed of basic raw materials and additives, the basic raw materials include 50% decomposed rice straw, 20% sludge and 30% vermiculite in weight ratio, and the additives are 1% ferrous sulfate, 1% superphosphate, 1% ammonium sulfate and 0.5% amino acid fertilizer added according to the total weight of the basic raw materials.

[0008] Preferably, the decomposed rice straw is obtained by soaking the rice straw harvested in autumn in a 1% calcium hydroxide solution for 36 to 60 hours, then transferring it to a 1% ferrous sulfate solution for soaking for 12 to 36 hours, and then adding 1% of a self-developed HT20 decomposing bacteria agent and 1% of urea according to the dry weight of the rice straw for composting after calcium hydroxide-ferrous sulfate combined pretreatment, and the rice straw can be completely decomposed after 30 to 50 days.

[0009] The self-developed HT20 decomposition bacteria agent is composed of the following raw materials in parts by weight: 20 to 50 parts of Isoptericola sp., 2 to 50 parts of Trichoderma longibrachiatum, 20 to 50 parts of Streptomyces finlayi, 20 to 50 parts of Staphylococcus sp., 10 to 30 parts of Bacillus subtilis and 10 to 30 parts of Bacillus mucilaginosus.

[0010] Preferably, the biogas residue comes from agricultural waste produced by a biomass energy company.

[0011] The present invention also provides a method for preparing the rice straw and biogas residue-based seedling raising substrate, which comprises weighing basic raw materials and additives according to a formula ratio and mixing them evenly.

[0012] The present invention also provides an application of the rice straw and biogas residue-based seedling raising substrate, wherein the seedling raising substrate is used for raising rice seedlings by machine transplanting.

[0013] The present invention has significant technical effects due to the adoption of the above technical solution:

[0014] 1. The present invention provides a localized, low-cost, environmentally friendly rice seedling raising matrix, which not only solves the problem of uneven quality of rice seedlings transplanted by machines in the rice-growing areas of eastern Hebei, but also develops a diversified utilization technology of rice straw. At the same time, it finds a reasonable way for the resource utilization of biogas residue agricultural waste. It can not only promote the resource utilization process of rice straw and biogas residue, reduce environmental pollution, and protect the ecological environment, but also has good economic, ecological and social benefits, which is conducive to the green and sustainable development of agriculture.

[0015] 2. The present invention utilizes rice straw harvested in autumn and accelerates the straw composting progress by adding a self-developed HT20 composting bacteria agent that can be started at low temperature, thereby promoting rapid composting of the rice straw in autumn and winter, and can be used as a raw material for rice seedling substrate in the spring of the following year. This not only realizes the green recycling of rice straw, but also provides a new technical method for the diversified utilization of rice straw.

[0016] 3. The alkaline nitrogen content of the seedling medium of the present invention is 1204 mg / kg, the available phosphorus content is 730 mg / kg, the available potassium content is 2841 mg / kg, the pH is 7.19, the conductivity is 3.23 mS / cm, the total porosity is 82%, and the bulk density is 0.30 g / cm 3 Compared with the nutrient soil prepared by farmers themselves, the present invention uses decomposed rice straw and biogas residue mixed with vermiculite as the basic raw materials, which reduces the bulk density of the rice machine-transplanted seedling medium, reduces the burden of transportation in actual production, and adds ferrous sulfate, amino acid fertilizer, etc. as acidifiers for the seedling medium, which can not only adjust the pH value of the seedling medium, but also increase the chlorophyll content of the leaves and improve the quality of the seedlings.

[0017] 4. The present invention uses a rice seedling raising substrate mixed with decomposed rice straw, biogas residue and vermiculite, and the cost of raising rice seedlings is about 0.7 yuan / tray; the commercialized rice seedling raising substrate purchased on the market has a cost of about 2 yuan / tray, which has the risk of long-distance transportation; the cost of raising rice seedlings with nutrient soil made by farmers is about 0.3 yuan / tray, and the resources of natural soil are limited and cannot be mined without limit. At the same time, the homemade nutrient soil has a large volume, which not only increases the labor, but also increases the degree of wear on the rice transplanter. The present invention provides a green, pollution-free and low-cost rice seedling raising substrate for rice seedling raising, which can replace the rice seedling raising substrate made by farmers using natural soil and the commercialized rice seedling raising substrate purchased on the market, which can not only ensure the quality of rice seedlings, but also reduce the cost of raising rice seedlings, reduce mechanical wear, and improve the economic value of rice.

[0018] The present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a dynamic diagram of tillering of rice seedlings of different varieties cultivated with different seedling raising substrates under field conditions in Example 3 of the present invention;

[0020] Figure 2 It is a dynamic diagram of plant height growth of rice seedlings of different varieties cultivated with different seedling raising substrates under field conditions in Example 3 of the present invention. DETAILED DESCRIPTION

[0021] Example 1

[0022] This embodiment is about the screening of basic raw materials for the substrate of rice seedlings transplanted by machine.

[0023] Composting rice straw: Use the rice straw harvested in autumn, soak it in a 1% calcium hydroxide solution for 48 hours, then transfer it to a 1% ferrous sulfate solution and soak it for 24 hours. After pretreatment with calcium hydroxide and ferrous sulfate, add 1% of the self-developed HT20 composting agent and 1% of urea according to the dry weight of the rice straw. Start to treat the straw and compost it in mid-November. After 50 days, the straw can be completely decomposed. Among them, the self-developed HT20 composting agent is composed of the following raw materials in parts by weight: 20 parts of Isoptericola sp., 20 parts of Trichoderma longibrachiatum, 20 parts of Streptomyces finlayi, 50 parts of Staphylococcus sp., 30 parts of Bacillus subtilis and 30 parts of Bacillus mucilaginosus.

[0024] The sludge comes from agricultural waste produced by biomass energy companies in eastern Hebei Province and has high nutritional value.

[0025] 1. Basic physical and chemical properties of basic raw materials

[0026] The basic physical and chemical properties of decomposed rice straw, biogas residue raw materials and commercial rice seedling substrate (Jiangsu Chaimihe Co., Ltd.) are shown in Table 1. It can be found from the table that the pH of decomposed rice straw, biogas residue, etc. is relatively high, significantly higher than the acid standard of rice seedling substrate, the conductivity of decomposed rice straw and biogas residue is higher than that of commercial substrate, and the potassium ion and sodium ion content are significantly higher than that of commercial substrate, the organic matter content is as high as 700g / kg-1100g / kg, and it has rich fast-acting potassium nutrients, but the alkaline nitrogen content is slightly lower than that of commercial substrate. In the later stage of raw material ratio process, attention should be paid to the adjustment of substrate formula pH, the influence of ions on seedling quality, insufficient nitrogen content and other issues.

[0027] Table 1 Basic physicochemical properties of commercial matrix and raw materials of the present invention

[0028]

[0029] 2. Screening of the formula for the medium for rice seedlings transplanting by machine

[0030] The commercial seedling medium was used as the control group (CK-base), and the rest were treated groups. The specific raw material ratios of each treatment are shown in Table 2. 3 ) Add 50g of commercial soil acidifier to the substrate.

[0031] Table 2 Specific raw material ratios for different treatments

[0032]

[0033]

[0034] The results of the investigation of seedlings with different treatments are shown in Table 3. Except for the CK-base, the seedlings in the other treatments were yellow-green in color, with narrow and short leaves. The seedlings in some treatments were uneven and the heights of the seedlings were different. From the overall quality of the seedlings in treatments A1, A2, and A3, it is not the case that the larger the proportion of decomposed rice straw, the more conducive it is to the growth of seedlings. The use of 50% of decomposed rice straw in the formula can not only meet the normal growth of seedlings, but also reduce the inhibition of seedling growth by certain elements in the decomposed rice straw. Therefore, 50% of decomposed rice straw was finally selected, and some other raw materials were used to ensure the normal growth of seedlings.

[0035] Biogas residue is rich in nutrients, and vermiculite can maintain the permeability and water holding capacity of the substrate, so biogas residue and vermiculite are mixed with decomposed rice straw to prepare the seedling substrate. From the quality of the seedlings in treatments B4 and B5, the seedlings in treatment B5 have 4 leaves, and the stem base width and leaf width are slightly higher than B4, and the overall color of the seedlings is slightly greener than that of other treatments. Therefore, the B5 formula was finally used as the basis for the research on the seedling substrate formula.

[0036] Table 3 Survey results of seedling quality under different treatments

[0037]

[0038] Through the above experiments, it was determined that the basic raw material ratio of the medium for rice machine transplanting seedlings is 50% decomposed rice straw + 20% biogas residue + 30% vermiculite.

[0039] Example 2

[0040] This embodiment is about the screening of substrate acidifiers and nutrient fertilizers for rice seedlings transplanted by machine.

[0041] 1. Indoor test

[0042] 5 g of seedling substrate base material (50% decomposed rice straw + 20% biogas residue + 30% vermiculite) was added to a 100 mL conical flask. At the same time, ferrous sulfate, superphosphate, ammonium bicarbonate, monoammonium phosphate and ammonium sulfate were added to the conical flask according to different concentrations. 50 mL of distilled water was added. After shaking and filtering, the pH and conductivity were measured. The results are shown in Table 4. It can be seen from Table 4 that as the concentration of ferrous sulfate increases, the pH value becomes lower and lower, the matrix gradually becomes acidic, but the conductivity increases; as the concentration of superphosphate increases, the pH and conductivity increase at a low rate, and the overall trend is stable; the pH of the matrix with ammonium bicarbonate added is alkaline, which may be due to the fact that after ammonium bicarbonate is dissolved in water, the main free ions are bicarbonate ions and ammonium ions, and the degree of hydrolysis of bicarbonate ions is greater than that of ammonium ions, resulting in a higher concentration of hydroxide ions, which ultimately leads to an alkaline solution; as the concentration of monoammonium phosphate increases, the pH decreases slightly, the decrease is not large, about 6, but the conductivity increases significantly, when the concentration of monoammonium phosphate added is 5%, the pH is about 5.92, and the conductivity is 4.36mS / cm; as the concentration of ammonium sulfate increases, the pH changes slightly, about 7, and ammonium sulfate is a typical acidic fertilizer that can provide nitrogen fertilizer for plants.

[0043] Table 4 Effects of adding different acidic fertilizers on pH and conductivity of seedling substrate

[0044]

[0045]

[0046] After compounding different acid-adjusting fertilizers, the effects on the pH and conductivity of the rice seedling medium were measured. The results are shown in Table 5. When the concentration of ferrous sulfate is constant, increasing the concentration of superphosphate can only slightly reduce the pH, but increase the conductivity. Therefore, in the compounding process, the concentration of superphosphate can be 1%. As the concentration of monoammonium phosphate and ammonium sulfate increases, the conductivity will increase. Therefore, when selecting acidic fertilizers of different concentrations, it is best to ensure that the pH is reduced while the conductivity is not increased.

[0047] Table 5 Effect of adding compound acidic fertilizer on pH and conductivity of seedling substrate

[0048]

[0049]

[0050] 2. Greenhouse test

[0051] According to the results of the indoor test on pH and conductivity, single acidification and compound acidification treatments were selected, which could reduce the pH of the substrate and have a slightly lower impact on conductivity. The effects of adding different acidification treatments on the basic physical and chemical properties of the substrate for machine-transplanted rice seedlings were measured. At the same time, the quality of rice seedlings was measured in a certain period through greenhouse seedling experiments, and the effects of adding different acidification agents on rice seedlings were evaluated, and relatively suitable acidification treatments were selected. The experimental scheme is shown in Table 6.

[0052] Table 6 Experimental scheme of adding different acid regulators

[0053]

[0054] The results of adding different acidifiers on the basic physical and chemical properties of the rice machine transplanting seedling substrate are shown in Table 7. It can be seen from Table 7 that the addition of ferrous sulfate and superphosphate cannot increase the content of alkaline nitrogen in the substrate, but the treatment of monoammonium phosphate and ammonium sulfate increases. The content of alkaline nitrogen increases with the increase of the added concentration, but monoammonium phosphate will greatly increase the content of available phosphorus in the substrate, and excessive phosphorus has a certain toxic effect on rice seedlings; the content of alkaline nitrogen also increases significantly with the increase of the added concentration of ammonium sulfate, but the increase in conductivity is large. Therefore, the selection of low concentration of ammonium sulfate can not only increase the content of alkaline nitrogen in the substrate, but also solve the problem of excessive conductivity. Although superphosphate cannot increase the content of alkaline nitrogen in the substrate, the addition of calcium ions has a promoting effect on improving the quality of rice seedlings. Similarly, the iron ions in ferrous sulfate can promote the synthesis of leaf chlorophyll.

[0055] Table 7 Effects of adding different acidifiers on basic physical and chemical properties of rice seedling medium

[0056]

[0057]

[0058] The results of the effects of adding different acidifiers on rice seedlings are shown in Table 8. When ferrous sulfate and ammonium sulfate were added, the SPAD value of the seedlings was relatively high and the leaves were greener. When ammonium sulfate was added at the same time, the maximum leaf width could reach 4.2-4.6cm, and the leaves were wide and green. However, the seedlings treated with only superphosphate were narrow and thin, and the leaves were yellow. Therefore, ferrous sulfate and ammonium sulfate can improve the quality of rice seedlings, and the leaves of rice seedlings are dark green, wide and thick.

[0059] Table 8 Effects of different acid treatments on rice seedlings

[0060] deal with SPAD value Maximum leaf width / cm Stem diameter / cm CK base 32.28±2.61 4.54±0.07 2.48±0.15 A1 22.95±1.26 3.61±0.10 1.77±0.10 A2 20.99±1.74 3.52±0.06 1.89±0.01 A3 22.95±1.85 3.49±0.12 1.86±0.08 A4 22.43±1.75 3.52±0.11 1.83±0.12 B1 14.97±1.44 3.54±0.11 1.68±0.05 B2 19.99±2.85 3.51±0.09 1.67±0.19 B3 18.99±3.71 3.81±0.14 1.89±0.21 B4 15.79±2.37 3.41±0.08 1.74±0.08 B5 16.41±1.92 3.47±0.20 1.87±0.10 C1 18.85±0.97 3.98±0.08 2.06±0.06 C2 19.14±1.49 4.26±0.01 2.07±0.03 C3 17.99±0.76 4.22±0.09 2.00±0.03 C4 17.48±0.56 4.28±0.11 1.97±0.05 D1 22.39±1.84 4.24±0.13 2.15±0.11 D2 23.62±2.90 4.48±0.10 2.02±0.09 D3 26.12±1.09 4.64±0.34 2.12±0.26 D4 26.31±1.02 3.35±0.04 2.35±0.10

[0061] Amino acid fertilizer can stimulate and regulate the rapid growth of plants, promote the absorption of nutrients, enhance the metabolic function of plants, improve photosynthesis, promote the development of plant root systems, and accelerate plant growth and reproduction. By setting up an amino acid fertilizer addition test and measuring the basic physical and chemical properties of the rice machine transplanting seedling substrate and the quality of rice seedlings, the effect of amino acid fertilizer was evaluated. Its formula is shown in Table 9.

[0062] Table 9 Experimental formulas for adding different amino acid fertilizers

[0063]

[0064] The effects of adding different amino acid fertilizers on the physical and chemical properties of the rice machine transplanting seedling substrate are shown in Table 10. After adding amino acid fertilizer, the content of alkaline nitrogen increased with the increase of amino acid fertilizer concentration, but the conductivity and available potassium also increased, and the effect on pH and available phosphorus was not significant. When ammonium sulfate and amino acid fertilizer were added at the same time, the conductivity value reached 2.6-3.95mS / cm, and the conductivity increase was slightly higher. However, when ammonium sulfate and amino acid fertilizer were added at the same time, the content of alkaline nitrogen reached more than 1000mg / kg, which can increase the nitrogen content in the substrate.

[0065] Table 10 Effects of adding different amino acid fertilizers on the physical and chemical properties of the medium for rice machine transplanting seedlings

[0066]

[0067]

[0068] The effects of adding different amino acid fertilizers on the quality of rice seedlings are shown in Table 11. When the amount of amino acid fertilizer added is above 1%, the SPAD value of rice seedlings increases, and the leaves are dark green. When the amount of amino acid fertilizer added is 2%, from the various indicators of seedling quality, the quality of seedlings is not much different from that of the CK matrix treatment, but from the results of the physical and chemical properties in the above table, its conductivity content reaches 3.52mS / cm, and the conductivity is too high, which has a slight impact on the early emergence. When amino acid fertilizer and ammonium sulfate are added in combination, the SPAD value of rice seedlings is greatly improved, and the maximum leaf width, stem thickness, and plant height are all higher than those of single amino acid fertilizer. Among them, the seedling quality of the B4 treatment group is not much different from that of the commercial matrix, and the alkaline nitrogen content is the highest, reaching 1750mg / kg, but the conductivity reaches 3.95mS / cm, which is slightly higher. The seedling effect of the B3 treatment group is second only to that of the B4 treatment group. At the same time, its conductivity value is 2.88mS / cm, which has little effect on the early emergence of seedlings. The seedlings emerge in an orderly manner. After emergence, the leaves are dark green, the stems are thick and the leaves are wide, which meets the standards for machine-transplanted rice seedlings.

[0069] Table 11 Effects of adding different amino acid fertilizers on rice seedlings

[0070]

[0071]

[0072] Superphosphate fertilizer can improve soil aggregate structure and soil environment. Therefore, different concentrations of superphosphate fertilizer addition experiments were set up to further improve the formula of rice machine transplanting seedling matrix by measuring the physical and chemical properties of the matrix and the quality indicators of the seedlings. The treatments of adding different superphosphate fertilizers are shown in Table 12.

[0073] Table 12 Experimental formulas with different superphosphate fertilizers

[0074]

[0075] The effects of adding different superphosphate fertilizers on the physical and chemical properties of the rice machine transplanting substrate are shown in Table 13. Adding 1% superphosphate will increase the content of available phosphorus compared to adding 0.5% superphosphate, but has no effect on available potassium. After adding superphosphate to a certain extent, the substrate pH will appear neutral, but because ammonium sulfate will be absorbed along with ammonium ions, sulfate ions will appear acidic. The alkaline nitrogen and conductivity of the C3 treatment group are the highest among all treatment groups, with a conductivity of 4.10mS / cm. Due to its high conductivity, it is not suitable as a substrate formula.

[0076] Table 13 Effects of adding different superphosphate fertilizers on the physical and chemical properties of the medium for rice machine transplanting seedlings

[0077]

[0078]

[0079] The effects of adding different superphosphate fertilizer treatments on the quality of rice seedlings are shown in Table 14. The C3 treatment group with the highest alkaline nitrogen content had the highest SPAD value, dark green leaves, wide and thick leaves, and thick stems. The seedling quality was the same as the CK substrate treatment, but due to the high conductivity of its substrate, the early emergence of seedlings was uneven. The SPAD value of the C2 treatment group was 28.94, with green leaves, wide leaves and thick stems, dense and strong root systems, and neat emergence. Therefore, the final formula for machine-transplanted seedlings was the C2 treatment group, that is, 50% decomposed rice straw + 20% biogas residue + 30% vermiculite + 1% ferrous sulfate + 1% superphosphate + 1% ammonium sulfate

[0080] +0.5% amino acid fertilizer.

[0081] Table 14 Effects of adding different superphosphate fertilizers on rice seedlings

[0082] deal with SPAD value Maximum leaf width / cm Stem diameter / cm Plant height / cm Number of seedlings CK-based 32.39±2.27 4.6±0.11 2.58±0.25 16.73±1.33 3.20±0.35 C1 27.75±0.92 4.33±0.21 2.32±0.08 16.67±0.31 3.13±0.23 C2 28.94±1.20 4.69±0.61 2.40±0.35 15.93±0.50 3 C3 32.77±1.11 4.91±0.12 2.67±0.06 16.00±1.11 3.20±0.20 C4 27.38±3.95 4.12±0.32 2.18±0.10 16.80±1.22 3.20±0.20 C5 28.61±4.36 4.72±0.19 2.57±0.32 15.73±0.50 3

[0083] Example 3

[0084] This example is to conduct field test verification using the seedling raising substrate formula obtained after screening in Examples 1 and 2.

[0085] Four rice varieties with different grain shapes (7233, 979, Zhonghua No. 8 and Xiangnuo No. 9) were selected, and rice seedlings were raised using a seedling raising substrate (50% decomposed rice straw + 20% biogas residue + 30% vermiculite + 1% ferrous sulfate + 1% superphosphate + 1% ammonium sulfate + 0.5% amino acid fertilizer) of the present invention and a commercial seedling raising substrate (from Jiangsu Chaimihe Co., Ltd.), respectively. After one month of cultivation, the rice seedlings were transplanted into the field, and the tillering number and plant height, as well as the influence on the rice yield components were regularly observed to comprehensively evaluate the difference between the seedling raising substrate (self-developed) of the present invention and the commercial seedling raising substrate (CK-based).

[0086] Figure 1 and Figure 2These are the tillering and plant height of different varieties of rice seedlings cultivated in different seedling raising substrates under field conditions. The solid line is the tillering and plant height changes of seedlings cultivated in the self-developed seedling raising substrate in the field, and the dotted line is the tillering and plant height changes of seedlings cultivated in the commercial substrate in the field. It can be seen from the figure that the number of tillers and plant height of the four different varieties of rice seedlings cultivated in two different substrates are not much different during the entire growth period of rice. Among them, the maximum number of tillers of rice seedlings cultivated in the self-developed seedling raising substrate is greater than that of rice seedlings cultivated in the commercial seedling raising substrate, and the final number of effective tillers is also higher than that of the CK substrate control group. During the seedling acclimatization period, the number of tillers is not much different, indicating that the rice seedlings cultivated in the self-developed substrate have a certain acclimatization ability and their seedling quality is relatively high. From the perspective of rice plant height, the two treatment groups were not much different, but the plant height of the self-developed matrix treatment group of Zhonghua No. 8 was lower than that of the CK matrix control group in the early stage, which may have caused the difference in plant height during the seedling stage. At the final harvest stage, there was no significant difference in plant height between the two treatment groups. Through the investigation of the number of tillers and plant height of rice seedlings, it was found that there was no significant difference in the field performance between the seedlings cultivated by the self-developed seedling raising matrix and the seedlings cultivated by the commercial seedling raising matrix, and no significant difference was found in the critical seedling growth stage.

[0087] The effects of different varieties of rice seedlings cultivated with different seedling raising substrates on the rice yield components are shown in Table 15. There is almost no difference in the thousand-grain weight and fruiting rate of the two treatment groups. The number of panicles of the rice seedlings in the self-developed treatment group is slightly higher than that of the CK matrix control group; for 7233 and Zhonghua No. 8, the number of panicles of the self-developed treatment group is slightly higher than that of the CK matrix control group, and its final theoretical yield value also increases accordingly, while the number of panicles of the self-developed treatment group of 979 and Xiangnuo No. 9 is slightly lower than that of the CK matrix control group, but the difference is not obvious. Although the rice seedlings cultivated with the self-developed seedling raising substrate may affect the rice yield components to a certain extent, there is no significant difference compared with the CK matrix control group. Therefore, the self-developed seedling raising substrate of the present invention can be applied to rice machine transplanting seedling raising, and its seedling quality is high, the seedling slowing ability is strong, and there is no significant effect on the rice yield components. It can completely replace the substrate with good performance on the market, and can reduce the cost of the seedling raising substrate in the region. At the same time, it realizes the resource utilization of waste in the region, and plays a pivotal role in the development of circular agriculture.

[0088] Table 15 Effects of rice seedlings grown in different seedling mediums on rice yield components

[0089]

[0090]

[0091] The seedling culture medium of the present invention has an alkali-hydrolyzed nitrogen content of 1204 mg / kg, an available phosphorus content of 730 mg / kg, an available potassium content of 2841 mg / kg, a pH of 7.19, an electrical conductivity of 3.23 mS / cm, a total porosity of 82%, and a bulk density of 0.30 g / cm 3 Compared with the nutrient soil prepared by farmers themselves, the present invention uses decomposed rice straw and biogas residue mixed with vermiculite as the basic raw materials, which reduces the bulk density of the rice machine-transplanted seedling medium, reduces the burden of transportation and mechanical wear in actual production, and uses ferrous sulfate, amino acid fertilizer, etc. as acidifiers for the seedling medium, which can not only adjust the pH value of the seedling medium, but also increase the chlorophyll content of the leaves and improve the quality of the seedlings.

[0092] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A rice straw and biogas residue-based seedling raising substrate, characterized in that: The seedling raising matrix is ​​composed of basic raw materials and additives. The basic raw materials include 30-80% of decomposed rice straw, 10-30% of biogas residue and 10-50% of vermiculite in terms of weight ratio. The additives are 1-5% of ferrous sulfate, 0.5-5% of superphosphate, 0-5% of ammonium bicarbonate, 0-5% of monoammonium phosphate, 0.5-5% of ammonium sulfate and 0.5-2% of amino acid fertilizer added according to the total weight of the basic raw materials.

2. The rice straw and biogas residue-based seedling raising substrate according to claim 1, characterized in that: The seedling raising matrix is ​​composed of basic raw materials and additives. The basic raw materials include 50% decomposed rice straw, 20% biogas residue and 30% vermiculite in weight ratio. The additives are 1% ferrous sulfate, 1% superphosphate, 1% ammonium sulfate and 0.5% amino acid fertilizer added according to the total weight of the basic raw materials.

3. The seedling raising substrate according to claim 1 or 2, characterized in that: The decomposed rice straw is prepared by soaking rice straw harvested in autumn in a 1% calcium hydroxide solution for 36 to 60 hours, then transferring the rice straw to a 1% ferrous sulfate solution for 12 to 36 hours, and then adding 1% of a self-developed HT20 decomposing bacteria agent and 1% of urea according to the dry weight of the rice straw for composting, and the rice straw can be completely decomposed after 30 to 50 days. The self-developed HT20 decomposition bacteria agent is composed of the following raw materials in parts by weight: 20 to 50 parts of Isoptericola sp., 2 to 50 parts of Trichoderma longibrachiatum, 20 to 50 parts of Streptomyces finlayi, 20 to 50 parts of Staphylococcus sp., 10 to 30 parts of Bacillus subtilis and 10 to 30 parts of Bacillus mucilaginosus.

4. The seedling raising substrate according to claim 1 or 2, characterized in that: The biogas residue comes from agricultural waste produced by a biomass energy company.

5. A method for preparing a rice straw and biogas residue-based seedling raising substrate according to any one of claims 1 to 4, characterized in that: The method is: weigh the basic raw materials and additives according to the formula ratio and mix them evenly.

6. An application of the rice straw and biogas residue-based seedling raising substrate according to any one of claims 1 to 4, characterized in that: The seedling raising substrate is used for raising rice seedlings by machine transplanting.

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