AU2020104314A4

AU2020104314A4 - Composition with Effects of Prevention and Control of Nitrogen and Phosphorus Loss and Improvement of Soil Fertility of Facility Vegetable Fields

Info

Publication number: AU2020104314A4
Application number: AU2020104314A
Authority: AU
Inventors: Luji Bo; Yongping Jing; Bing Li; Yan Li; Cuiping SUN; Ming Sun; Rongquan Zhang; Ziwen ZHONG
Original assignee: Shandong Provincial Geo Mineral Engineering Exploration Inst; Institute of Agricultural Resources and Environment of Shandong Academy of Agricultural Sciences
Current assignee: Shandong Provincial Geo-Mineral Engineering Exploration Institute; Institute of Agricultural Resources and Environment of Shandong Academy of Agricultural Sciences
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-03-18
Anticipated expiration: 2028-12-24

Abstract

The present invention provides a composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields, comprising the following components: 30-50 parts of modified straw powder, 20-30 parts of charcoal, 15-25 parts of shell powder, 10-15 parts of bentonite, 5-10 parts of chitosan oligosaccharide and 10-15 parts of edible fungi residue. The present invention improves the effective utilization of nitrogen and phosphorus by using the strong adsorption of modified straw powder, the chemical fixation of shell powder on phosphorus, the fixation of bentonite on ammonium nitrogen, and the denitrification transformation and microbial transformation of denitrifying bacteria on nitrate nitrogen in soil at a high carbon-nitrogen ratio, and effectively prevents and controls the nitrogen and phosphorus loss under the synergistic effect. The present invention also can improve physical and chemical properties of soil and soil fertility, activate soil microorganisms, improve the availability of nitrogen and phosphorus in soil, increase the utilization rate of nitrogen and phosphorus, reduce the application of fertilizer, and save cost.

Description

Description Composition with Effects of Prevention and Control of Nitrogen and Phosphorus Loss and Improvement of Soil Fertility of Facility Vegetable Fields Technical Field The present invention relates to a composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields, and belongs to the technical field of prevention and control of agricultural non-point source pollution. Background In the past 40 years, due to human factors, the nitrate concentration of shallow groundwater has been increasing continuously, and the problem of underground water pollution has attracted special attention in many countries. Intensive facility vegetable planting areas are the main areas of nitrate pollution in groundwater. In order to increase the yield of vegetable crops, the management mode of excessive application of fertilizer and frequent watering adopted by vegetable growers causes the accumulation of soil nutrients and the deterioration of groundwater environment. The average nitrogen application amount of greenhouse vegetables is 1382 kg N-hm-2, which is about 6-7 times that of wheat and core. With the extension of planting years, the nitrate concentration of groundwater shows an increasing trend and increases very rapidly. The higher the density of vegetable fields is, the more serious the groundwater pollution is. On the other hand, the traditional and laggard land use mode destroys the basic structure - granular structure of soil fertility and reduces the content of organic matters, and the long-term application of fertilizers will also cause soil acidification and soil hardening as well as poor physical and chemical properties, which results in decline in vegetable yield, thus forming a vicious circle. At present, to solve the contradiction between vegetable demand and ecological environment, an important aspect is to face up to the reality and objective need of high rate of fertilizer application, solve the problem of nitrogen and phosphorus environmental pollution under the condition of applying a large amount of chemical fertilizers, reduce and control the nitrogen and phosphorus content in soil of facility vegetable fields, reduce the risk of nitrogen and phosphorus leaching into groundwater, promote soil nutrient balance of vegetable fields, increase the resource utilization efficiency, improve the physical and chemical properties of soil and soil fertility and increase the vegetable yield. Therefore, the research of methods and measures for reducing nitrogen and phosphorus pollution and improving soil fertility has important practical significance for promoting sustainable development of facility vegetable industry and agricultural environmental protection.

The Chinese patent document CN 104230606 A (with the application No. 201410403856.3) discloses a special organic compound fertilizer for vegetable fields. The compound fertilizer is prepared in the form of granulation, the outer layer is Chinese herbal medicine residue organic fertilizer and the inner layer is Chinese herbal medicine residue and straight chemical fertilizer. Then organic compound fertilizers with different proportions of sludge and Chinese herbal medicine residue are produced by using the two-step method and the high-temperature and constant-temperature composting process. The patented product has the effect of reducing nitrogen loss but belongs to the field of fertilizer products. The Chinese patent document CN 103804051 A (with the application No. 201410037689.5) discloses a compound fertilizer for reducing nitrogen and phosphorus loss of soil for planting fruits and vegetables, which is an organic fertilizer composed of 10 part of N, 6.6-7.5 parts of K 2 0 and feces or an organic fertilizer composed of 4-5 parts of P 2 05 and feces, the inner layer is inorganic fertilizer, and the outer layer is granular fertilizer prepared from organic fertilizer, for reducing nitrogen and phosphorus loss of soil for planting fruits and vegetables. The patented product is a slow release fertilizer product and belongs to the field of fertilizer products. The Chinese patent document CN 105001024 A (with the application No. 201510437628.2) discloses a preparation with functions of nitrification inhibition and urease inhibition, which increases the nitrogen fertilizer utilization rate by reducing ammoniation of amide nitrogen and nitrification of ammonium nitrogen in ammonium nitrate urea and belongs to the field of stabilized fertilizer products. Summary In view of the defects in the prior art that the existing patents reduce nitrogen and phosphorus loss through source control from the point of fertilizer, the present invention develops a composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields from the point of prevention and control during nitrogen and phosphorus loss. The key point of the present invention is that the composition provides medium trace elements such as high carbon, calcium, magnesium, copper, zinc, iron and manganese for soil to improve soil fertility without bringing nitrogen and phosphorus nutrients into soil, and the nitrogen and phosphorus retention ability of soil can be improved through the synergistic effect of the components to reduce nitrogen and phosphorus loss. The first aspect of the present invention provides a composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields, which comprises the following components in parts by weight:

30-50 parts of modified straw powder, 20-30 parts of charcoal, 15-25 parts of shell powder, 10-15 parts of bentonite, 5-10 parts of chitosan oligosaccharide and 10-15 parts of edible fungi residue. Preferably according to the present invention, 35-45 parts of modified straw powder, 22 28 parts of charcoal, 18-22 parts of shell powder, 12-15 parts of bentonite, 5-8 parts of chitosan oligosaccharide and 10-15 parts of edible fungi residue. Wherein a modification method for straw powder (refer to the paper Research on Absorption Effect of Modified Agricultural Straw on Nitrate Radical and Phosphate Radical in Water) is provided: Pretreatment of straw: cleaning straw with distilled water first, drying at 60°C for 12 h, then crushing, and screening with a sieve of about 500 m to obtain straw powder which is sealed in a dryer for preservation. Modification of straw powder: (1) activating reaction stage: measuring 2-5 g of pretreated straw powder, placing in a mixed solution of 100-150 mL of N,N dimethylformamide (DMF) and 50-100 mL of epichlorohydrin, and heating and stirring in a water bath of 70-100°C for 0.5-2 h; (2) catalytic bridging reaction stage: adding 10-30 mL of pyridine solution as a catalyst to continue heating and stirring in the water bath of 70-100°C for 0.5-2 h; and (3) ring grafting reaction stage: adding 30-50 mL of dimethylamine (33%) solution to continue heating in the water bath of 70-100°C for 2-4 h to obtain grafted corn stalk powder (preliminary product); Cleaning of straw powder: a) cooling the grafted straw powder to the normal temperature, rinsing with 0.1 mol/L NaOH solution for 2-3 times, transferring into a glass beaker, pouring 500 mL of 0.1 mol/L NaOH solution, and heating and stirring strongly in a water bath of 30 °C for 5-10 min to remove ash, residues, part of polysaccharide and other substances; b) rinsing with 0.1 mol/L HCl solution for 2-3 times, transferring into a glass beaker, pouring 500 mL of 0.1 mol/L HC solution, heating and stirring strongly in the water bath of 30-40°C for 5-10 min, and adjusting the pH value to neutrality; c) rinsing with an ethanol aqueous solution with a concentration of 50% for 2-3 times, then placing in 500 mL of ethanol aqueous solution with a concentration of 50%, and heating and stirring strongly in the water bath of 30-40°C for 8-10 min to remove the residual organic reactants and the catalyst pyridine; and d) rinsing with 0.1 mol/L NaCl solution for 2-3 times, placing in 500 mL of 0.1 mol/L NaCl solution, and heating and stirring strongly in the water bath of 30-40°C for 5-10 min to obtain cleaned straw powder; Drying for use: drying the successfully grafted straw powder at 60-65°C for 10-12 h, sieving and grading to prepare anionic adsorbents with different particle diameters for use. According to the need of the present invention, preferably: the usage amounts of components in the preparation process of the modified straw powder are: 4 g of straw powder,

A

140 mL of N,N-dimethylformamide, 70 mL of epichlorohydrin and 20 mL of pyridine solution. The second aspect of the present invention provides a preparation method and an application method for the composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields. The preparation method comprises the following steps: (1) weighing modified straw powder, charcoal, shell powder, bentonite, chitosan oligosaccharide and edible fungi residue in parts by weight; (2) mixing the raw materials by a dry powder mixer for 10 min; (3) extruding and granulating, wherein the granulation conditions are that: the preheating time of the raw materials is 30 min, the temperature is 50-60°C, and the flow is 500 kg/h; and the particles are columnar and have a diameter of 3-5 mm and a length of 15-20 mm. The dry powder mixer is a newly developed high-efficiency and energy-saving machine for mixing putty cream and other chemical raw materials, which has simple structure, firmness, durability, small matched power, high efficiency, low energy consumption, simple operation, time saving, labor saving, and dispersing power up to 18000 and thus is ideal equipment for making putty powder cream and mixing chemical raw materials. The application method for the composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility is that: when the land of a greenhouse is tilled rotatably, the composition is applied into the soil together with the base fertilizer, the application depth is 0-30 cm, and the application amount of the composition is 500-1500 kg/mu. Preferably according to the present invention, the application amount of the composition is 1000-1500 kg/mu. Straw, as an absorption material, has the characteristics of large specific surface area, good adsorption performance and strong stability, and is often used for removing nitrate radical and phosphate radical in water but rarely used in soil to reduce nitrogen and phosphorus leaching loss; and moreover, the nutrient effect of straw returning to field and the effect of improving the farmland ecological environment are used to increase crop yield. In the present invention, the specific surface area of the modified straw powder is increased by more than 30%, and the decomposition rate and the mineralization ability of organic matter are also enhanced. Charcoal is a highly aromatic and stable organic material rich in carbon, which is produced by high-temperature pyrolysis (usually less than 700°C) of organic materials under the condition of complete or partial oxygen deficiency, providing a comprehensive solution for global climate change, food crisis and ecological pollution remediation. Charcoal can significantly improve the physical and chemical properties of soil: first, the porosity characteristic and the high specific surface area thereof are beneficial for soil to gather water, increase porosity and reduce bulk density; and the high-quality charcoal can contain more than 50% of humic acid which can promote the formation of soil granular structure, and can improve the structural characters when being applied together with straw, thus providing a good environment for plant growth. Meanwhile, charcoal can increase the content of soil organic carbon, and the charges and functional groups on the surface of charcoal are also conducive to retention of soil nutrients. Shell powder is powder formed by crushing shells, which is mainly composed of calcium carbonate, and contains abundant magnesium, a small amount of trace elements such as copper, iron, manganese and zinc, and amino acid. As an animal waste, shell powder can provide a certain guarantee for plant growth. With the development of greenhouse vegetables, calcium fertilizer receives more and more attention. Calcium is an important component of cytoplasmic membrane and cell wall, which influences the formation of new cells; and is also an activator of amylase and protease, which can promote the absorption of plant nutrients. Bentonite is a non-metallic mineral mainly composed of montmorillonite which has a 2:1 crystal structure composed of a layer of aluminum-oxygen octahedron sandwiched by two silicon-oxygen tetrahedra. The layered structure formed by montmorillonite unit cells has cations such as Cu, Mg, Na and K which have unstable effect with montmorillonite unit cells and are easy to be exchanged by other cations, thus having good ion exchangeability. Bentonite can form molecular grids of moist soil so as to fix ammonium nitrogen and also can reduce the volatilization of water molecules and save water. Chitosan oligosaccharide is an oligosaccharide composition with a degree of polymerization of 2-20 obtained by degrading chitosan by a special biological enzyme technology (also reported to use chemical degradation and microwave degradation technologies), which has a molecular weight less than or equal to 3200 Da, is a low molecular weight product with good water solubility, great effect and high biological activity and has many unique functions such as being easily absorbed by organisms. In the agricultural field, chitosan oligosaccharide can change soil flora, promote the growth of beneficial microorganisms, induce the disease resistance of plants, and become immune to and kill various fungi, bacteria and viruses, and can be developed into biological pesticides, growth regulators and fertilizers. Edible fungi residue refers to solid wastes left after cultivation of various edible fungi, for example, mushroom residue, pleurotus eryngii residue, shiitake mushroom residue, oyster mushroom residue, straw mushroom residue and needle mushroom residue, or mixtures of various residues. Edible fungi residue has the physical property of porosity and contains abundant organic matters, bioactive components and various soluble organic nutrients. Edible fungi residue also contains medium nutrient elements such as calcium, magnesium and sulfur, trace elements such as copper, zinc, iron and manganese, various microorganisms, and other active substances such as enzyme, which can provide abundant organic and inorganic nutrients for soil. Beneficial mycelium and active biological enzyme which are contained can significantly increase the number of beneficial microorganisms in soil, improve the soil microbial community structure and enhance soil biological activity, and plays a positive role in improving the physical and chemical properties and microecological environment of soil. The application of residues into soil is not only conducive to formation of soil granular structure, improvement of soil water retention ability, increase of soil permeability, improvement of soil physical properties and promotion of plant growth, but also can improve soil fertility, increase the content of soil organic matters and nutrients as well as the availability thereof, and improve soil microbial activity. The mechanism by which the composition of the present invention prevents and controls nitrogen and phosphorus loss and improves soil fertility is that: a) In the composition, the modified straw powder has strong interception and adsorption effects on nitrate nitrogen and phosphate radical in soil; calcium ions in the shell powder can form calcium phosphate precipitation with phosphate radical, which can be temporarily stored in soil; bentonite can adsorb fixed ammonium nitrogen ions; and the synergistic effect is used to keep the balance of nitrogen and phosphorus nutrient content in soil and nitrogen and phosphorus absorbed by crops, slow down nitrogen and phosphorus leaching loss and increase the utilization of nitrogen and phosphorus; b) The straw powder, the charcoal, the residue and the chitosan oligosaccharide in the composition can continuously provide carbon sources at all levels, activate denitrifying bacteria in the hypoxia environment of subsoil, and convert NO3- into NH4+ and N 2 through denitrification, NH4+ is fixed by bentonite and the like, and the charcoal can reduce the release of gases such as N 2 and N 2 0 and reduce the loss of nitrogen sources and the leaching loss of NO3- in soil; c) The application of the composition as a high carbon material can effectively regulate the conversion of nitrogen by using the high carbon nitrogen promotion principle, and the composition can be used as a regulating agent for the availability of phosphorus; and under the high carbon permeability environment of surface soil, the composition can activate soil microorganisms, increase the nutrient conversion rate, improve the availability of nitrogen and phosphorus in soil, and increase the nutrient utilization rate; d) The straw powder can increase the content of organic cementing substance in soil, abundant humus in the charcoal is a good cementing agent for granular structure, the application of the residue is also beneficial to the formation of granule structure, and through the exchange of cell structure and inorganic salt in soil, the bentonite can make soil have water retentivity, nutrient preserving capability and permeability, improve the physical structure of soil, and provide a good growth environment for crops.

e) The application of the composition into soil can prevent and control nitrogen and phosphorus loss, return nitrogen and phosphorus to the field, fix carbon, reduce discharge, supplement high carbon nutrients and medium trace elements, increase the content of soil organic matters, and continuously improve soil fertility. The present invention has the following beneficial effects: 1. The nitrogen and phosphorus loss is prevented and controlled, and the effect is significant: the present invention improves the effective utilization of nitrogen and phosphorus by using the strong adsorption of modified straw powder in the composition, the chemical fixation of shell powder on phosphorus, the fixation of bentonite on ammonium nitrogen, and the denitrification transformation and microbial transformation of denitrifying bacteria on nitrate nitrogen in soil at a high carbon-nitrogen ratio, and effectively prevents and controls the nitrogen and phosphorus loss under the synergistic effect, and the effect is significant. The specific results are shown in Table 2. 2. The physical and chemical properties of soil and soil fertility are improved: the composition has strong property of fertilizer and water retention, increases the polymerization stability of soil, improves the soil granular structure, improves the porosity and permeability of soil, and provides a good growth environment for crops; and the application of the composition as a high carbon material can improve the soil microbial community structure, increase the content of soil organic matters, and improve soil fertility. The continuous cropping obstacle is broken, and continuous cropping yield is almost unaffected. 3. Labor and materials are saved: when the land of a greenhouse is prepared, the application of the composition together with the base fertilizer avoids single labor input; and the composition is suitable for various fertilizing habits and planting patterns, and is applied on the basis of not changing the fertilizing methods of farmers, with strong practicability. 4. The raw materials are environment-friendly and easy to obtain, and the cost is saved: the composition can activate soil microorganisms at a high carbon-nitrogen ratio, improve the availability of nitrogen and phosphorus in soil, increase the utilization rate of nitrogen and phosphorus, reduce the application of fertilizer, and save cost. The raw materials of the composition are cheap and easy to obtain, and can fix carbon and reduce discharge after being returned to the field, which realizes the reuse of waste resources and reduces the cost while improving the agricultural environment. Detailed Description The technical solution of the present invention and the technical effect produced thereby are further described below in combination with the specific test methods. The description below is only intended to explain the present invention but not to limit the present invention in any way. Any alternation or replacement made on the basis of the present invention belongs to the protection scope of the present invention. The methods described in the present invention are conventional methods in the art unless otherwise specified. Description of raw materials: straw powder is prepared by crushing straw with a straw crusher; and the preparation method for the modified straw powder is as mentioned above. The charcoal, the shell powder, the bentonite and the chitosan oligosaccharide in the embodiments are common commercial products. Embodiments The usage amounts of components in the compositions of the embodiments are shown in Table 1 below, in parts by weight: Table 1 Usage Amounts of Components in Embodiments (in part by weight)

The preparation method comprises the following steps: (1) weighing modified straw powder, charcoal, shell powder, bentonite, chitosan oligosaccharide and edible fungi residue in parts by weight; (2) mixing the raw materials by a dry powder mixer for 10 min; (3) extruding and granulating, wherein the granulation conditions are that: the preheating time of the raw materials is 30 min, the temperature is 50°C-60°C, and the flow is 500 kg/h; and the particles are columnar and have a diameter of 3-5 mm and a length of 15-20 mm. Test example 1: The using effects of the compositions of the above embodiment and the reference example in new greenhouses are compared in 2016. Application examples 1-4 respectively adopt the compositions of the above embodiments 1-4. When the land of a greenhouse is tilled rotatably, the composition is applied into the soil together with the base fertilizer, the application depth is 0-30 cm, and the application amount is 1000 kg/mu. The reference example adopts the composition comprising the following components: 40 parts of modified straw powder, 25 parts of charcoal, 20 parts of shell powder, 10 parts of bentonite, 7 parts of chitosan oligosaccharide and 13 parts of edible fungi residue, which is prepared according to the same method as the present invention. The application method is also that when the land of a greenhouse is tilled rotatably, the composition is applied into the soil together with the base fertilizer, the application depth is 0-30 cm, and the application amount is 1000 kg/mu. The control example CK is a blank control group where the above composition is not applied. When cucumber is planted in the facility vegetable field of a new greenhouse, the application examples, the reference example and the control example have the same planting areas and identical fertilization levels and field management measures. After the cucumber is harvested, the nitrogen and phosphorus leaching amount in soil is determined. The results are shown in Table 2 below:

Table 2 Influence of Composition of the Present Invention on Control of Nitrogen and Phosphorus Loss in Facility Cucumber Field Total Nitrogen Total Phosphorus Application Example Treatment Leaching Amount Leaching Amount kg/hm2 kg/hm2 Control Example CK No application 115.80+3.82 3.95±0.51

Application Example 2 Composition of 67.682.27 2.15±0.36 Embodiment 2 6.822 503 Application Example 3 Composition of 74.251.26 3.05±0.42 Embodiment 3 .512 .504 Application Example 4 Composition of 77.292.42 2.98±0.58 Embodiment 4 7.924 805 Reference Example Compositionof 81.05+2.18 3.56±0.29 Reference Example

It can be concluded from Table 2 that: (1) After the composition of the present invention is applied into the facility vegetable field, the nitrogen and phosphorus leaching loss in soil can be significantly reduced, the maximum (application example 2) total nitrogen (TN) leaching amount is reduced by 41.6%, and the total phosphorus (TP) leaching amount is reduced by 45.6%. (2) The usage amounts of the components used in the compositions of the application example 2 and the reference example are the same, except that modified straw powder is used in the application example 2 and straw powder is directly used in the reference example. The difference between the application example 2 and the reference example in reducing the nitrogen and phosphorus leaching loss is significant. In the application example 2, the total nitrogen (TN) leaching amount is reduced by 41.6%, and the total phosphorus (TP) leaching amount is reduced by 45.6%. In the reference example, the total nitrogen (TN) leaching amount is reduced by 30%, and the total phosphorus (TP) leaching amount is reduced by 9.8%. This indicates that the modified straw powder is more effective in reducing nitrogen and phosphorus loss in soil. Test example 2: cucumber is continuously planted for three crops in the planting areas of the application examples, the reference example and the control example in the above test example 1 in 2016-20167. The application amount and the yield statistics of facility cucumber in 2016-2017 are shown in Table 3. The field management and others are the same as those of the conventional facility cucumber cultivation. After continuous planting for three crops, the soil nutrients are analyzed, and the results are shown in Table 4. Table 3 Application Amount and Yield of Cucumber after Continuous Planting for Three Crops

Application First Crop Second Crop Third Crop

1 n\

Example Yield Application Yield Application Yield ApplicationAmount/mu kg/mu Amount/mu kg/mu Amount/mu kg/mu Control 16 m3 of organic fertilizer, Thesameas Thesameas Example 45 kg of N, 30 kg of P 2 05 , 12001 first crop 11259 first crop 10136 CK 50 kg of K2 0 Application 15 m 3 of organic fertilizer, The same as 12154The same as 11948 N,25kgOfP 0 , 12254 first crop first crop Examle11 40 kgof Example 45kgof K2O 2 5 Application The same as application 12366 The same as 12200 The same as 12008 Example 2 example 1 first crop first crop Application The same as application 12342 The same as 12071 The same as 11927 Example 3 example first crop first crop Application The same as application 12351 The same as 12206 The same as 11979 Example 4 example 1 first crop first crop Reference The same as application 12102 The same as 11555 The same as 11246 Example example first crop first crop

It can be seen from Table 3 that the application examples 1-4 using the composition of the present invention have higher yield than the control group with the application amount lower than the control group. Especially after continuous planting for three crops, the yield of the control group is reduced by 15.5%. The yield of the application group using the composition of the present invention is almost unaffected. After continuous planting for three crops, the nutrients of surface oil are analyzed, organic matters, alkali-hydrolyzable nitrogen, rapidly available phosphorus, rapidly available potassium and pH value are determined, and the results are shown in Table 4. Table 4 Measurement Results of Soil Nutrients

Alkali- Rapidly Organic Hydrolyzable Available Rapidly Available pH Value Matter Nitrogen(ppm) Phosphorus Potassium(ppm) Nitrogen((ppm) Control Example 3.66+0.25 126.4 16.3 69.9+8.5 186.2±20.5 6.62 CR1 Application 4.01 0.86 149.5 10.2 79.6 7.5 200.4 24.8 7.64 Example 1 Application 4.25+0.59 156.8+14.6 82.2+ 10.6 221.8+16.8 7.66 Example 2 Application 4.43+0.38 140.7+12.3 76.9±5.8 216.6 21.5 7.61 Example 3 Application 4.39±0.47 142.9 15.4 80.3±12.7 207.8±23.7 7.59 Example 4 Reference 3.99±0.39 137.6±20.3 79.4±6.9 197.3±18.4 7.50 Example

It can be seen from Table 4 that after continuous planting for three crops, the application examples 1-4 using the composition of the present invention have higher soil nutrient content than the control group with the application amount lower than the control example CK. Compared with the control example, the organic matter is increased by up to 21.0%, and

1 1 alkali-hydrolyzable nitrogen, rapidly available phosphorus and rapidly available potassium are respectively increased by up to 24.1%, 17.6% and 19.1%. The pH value is apparently higher than that of the control example, which indicates that the application of the composition of the present invention can alleviate soil acidification caused by continuous fertilization. It can be seen from the above test that the present invention has significant effect in preventing and controlling nitrogen and phosphorus loss and can activate soil microorganisms, improve the availability of nitrogen and phosphorus in soil, increase the utilization rate of nitrogen and phosphorus, reduce the application of fertilizer, improve soil fertility and physical and chemical properties of soil, and avoid yield loss caused by continuous cropping. The present invention makes full use of waste raw materials, which can not only effectively prevent and control nitrogen and phosphorus loss and reduce non-point source pollution of soil, but also have the effect of improving soil fertility in all aspects, thus being especially practical for vegetable growers.

Claims

Claims 1. A composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields, characterized by comprising the following components in parts by weight: 30-50 parts of modified straw powder, 20-30 parts of charcoal, 15-25 parts of shell powder, 10-15 parts of bentonite, 5-10 parts of chitosan oligosaccharide and 10-15 parts of edible fungi residue.
2. The composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields according to claim 1, characterized by comprising the following components in parts by weight: 35-45 parts of modified straw powder, 22-28 parts of charcoal, 18-22 parts of shell powder, 12-15 parts of bentonite, 5-8 parts of chitosan oligosaccharide and 10-15 parts of edible fungi residue.
3. The composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields according to claim 1 or 2, characterized in that the usage amounts of components in the preparation process of the modified straw powder are: 4 g of straw powder, 140 mL of N, N-dimethylformamide, 70 mL of epichlorohydrin and 20 mL of pyridine solution.
4. A method for preparing the composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields according to claim 1 or 2, characterized by comprising the following steps: (1) weighing modified straw powder, charcoal, shell powder, bentonite, chitosan oligosaccharide and edible fungi residue in parts by weight; (2) mixing the raw materials by a dry powder mixer for 10 min; (3) extruding and granulating; granulation conditions: the preheating time of the raw materials is 30 min, the temperature is 50-60°C, and the flow is 500 kg/h; and the particles are columnar and have a diameter of 3-5 mm and a length of 15-20 mm.
5. An application method for the composition with effects of prevention and control of nitrogen and phosphorus loss and improvement of soil fertility of facility vegetable fields according to claim 1 or 2, characterized in that when the land of a greenhouse is tilled rotatably, the composition is applied into the soil together with the base fertilizer, and the application depth is 0-30 cm.
6. The application according to claim 5, characterized in that the application amount of the composition is 10000-1500 kg/mu.