CN120642745A - Method for improving quality and yield of winter rape planted in saline-alkali soil - Google Patents

Abstract

The invention discloses a method for improving the quality and yield of winter rape planted in saline-alkali soil, which belongs to the technical field of crop planting and comprises the following steps of preparing soil and applying base fertilizer before rape is planted in 11 months in the same year, applying urea after emergence, applying straw fermentation biofertilizer 10-15 days before overwintering, applying urea after spring in the next year and harvesting in 4 months in the next year. According to the invention, different fertilizers are scientifically and reasonably applied to winter rape in different periods, especially, the straw fermentation biological fertilizer is applied before overwintering, so that the method plays roles in improving the soil environment, regulating the soil nutrients, promoting nutrient absorption and conversion and the like, effectively reduces the nitrate content of winter rape, simultaneously improves the vitamin C content, improves the yield of rape, and achieves the purpose of improving the quality and the yield of winter rape planted in saline-alkali soil.

Description

Method for improving quality and yield of winter rape planted in saline-alkali soil

Technical Field

The invention belongs to the technical field of crop planting, and particularly relates to a method for improving quality and yield of winter rape planted in saline-alkali soil.

Background

Saline-alkali soil is a special soil type, and has high salinity, low fertility and poor physicochemical properties, and is challenging to the growth and development of crops. The rape has remarkable advantages in the restoration and utilization of the saline-alkali soil, and the problems of slow growth, low yield, poor quality and the like of the conventional winter rape planting are common, so that the effective utilization of the saline-alkali soil agricultural resources and the development of the winter rape industry are restricted.

At present, technical researches on planting winter rape in saline-alkali soil have been advanced to some extent, but the technical researches still have the defects. For example, the traditional fertilization method ignores the soil specificity of the saline-alkali soil, so that the fertilizer utilization rate is low, even the salinization of the soil is aggravated, and meanwhile, the precise fertilization technology aiming at the growth cycle of the winter rape in the saline-alkali soil is lacking, so that the nutrient requirements of different growth stages of the winter rape cannot be met. In addition, the recycling of agricultural wastes such as straw is not fully paid attention to in saline-alkali soil agriculture, and resource waste and environmental pollution are caused.

Therefore, the development of the planting method aiming at the characteristics of the saline-alkali soil and capable of improving the quality and the yield of the winter rape has important significance.

Disclosure of Invention

The invention aims to provide a method for improving the quality and yield of winter rape planted in saline-alkali soil, so as to solve the problems in the prior art.

A method for improving quality and yield of winter rape planted in saline-alkali soil comprises the following steps of preparing soil and applying base fertilizer before rape is planted in 11 months of the current year, applying urea after emergence of seedlings, applying straw fermentation biofertilizer 10-15 days before overwintering, applying urea after spring of the next year, and harvesting in 4 months of the next year.

Further, the base fertilizer is applied by layered fertilization, the organic fertilizer is applied to the ground before plowing, the organic fertilizer is turned in along with deep plowing, and the ammonium bicarbonate, the calcium superphosphate, the potassium chloride and the boron fertilizer are applied to a shallow soil layer during shallow plowing.

In the invention, the organic fertilizer is rich in organic matters, and can increase the aggregate structure of soil after being ploughed into soil with deep ploughing. The good aggregate structure can loosen and porous soil, and improve the air permeability and water permeability of the soil. The good air permeability can promote the leaching of salt in soil, reduce the accumulation of salt in the rape root system, provide a relatively suitable soil environment for the growth of the rape root system, be favorable for the absorption of moisture and nutrients by the root system, and further improve the yield and quality of rape.

Sufficient nitrogen fertilizer supply can promote the growth of rape leaves, increase leaf area, improve photosynthesis efficiency, and provide sufficient substances and energy for the growth and development of rape. The phosphorus element plays an important role in the root system development, flower bud differentiation and seed formation of the rape, and can enhance the cold resistance and drought resistance of the rape. The potassium element can improve the disease and pest resistance and lodging resistance of the rape, promote the synthesis and transportation of carbohydrate and improve the quality of the rape. Boron element is one of trace elements necessary for rape growth, and has important influence on rape pollen germination, pollen tube elongation and fertilization process. And in shallow cultivation, the superphosphate, the potassium chloride and the boron fertilizer are applied to a shallow soil layer, so that the fertilizer is more similar to the root system distribution area of the rape, and the quick absorption and utilization of the rape in the seedling stage and the early growth stage are facilitated. The nutrients of the saline-alkali soil are often unbalanced, and nutrient elements lacking in the soil can be supplemented by shallow application of the fertilizers, so that the soil nutrient balance is regulated, and a good nutrient environment is provided for rape growth.

Further, the application amount of the organic fertilizer is 150-180 kg/mu, the application amount of the ammonium bicarbonate is 20-25 kg/mu, the application amount of the superphosphate is 15-20 kg/mu, the application amount of the potassium chloride is 10-15 kg/mu, and the application amount of the boron fertilizer is 0.8-1.0 kg/mu.

Further, the application amount of the urea after emergence is 8-10 kg/mu, and the application amount of the urea after next spring is 10-15 kg/mu.

Further, the application amount of the straw fermentation bio-fertilizer is 50-80 kg/mu.

Further, the preparation method of the straw fermentation biological fertilizer comprises the following steps:

Crushing straw and adding water to mix uniformly to obtain a fermentation raw material, inoculating a decomposed mixed bacterial liquid into the fermentation raw material, regulating the water content of the material to 50-60%, carrying out composting fermentation to obtain a decomposed material, adding waste residues of a starch mill, sodium humate and sodium alginate into the decomposed material, mixing uniformly, regulating the pH value of the mixture, regulating the water content of the material to 50-60%, carrying out enzymolysis, adding a trace element fertilizer and a compound regulating bacterial liquid into the obtained enzymolysis liquid, regulating the water content of the material to 50-60%, carrying out secondary fermentation, drying the obtained secondary fermentation material, and granulating to obtain the straw fermentation biological fertilizer.

The decomposed mixed bacterial solution comprises 3 parts of lactobacillus plantarum solution, 1.5 parts of bacillus subtilis solution, 1 part of trichoderma viride solution, 2 parts of thermophilic bacillus licheniformis solution and 2 parts of candida utilis solution in parts by mass;

Further, the mass ratio of the straw to the water is (3-5) to 1, and/or the decomposed mixed bacterial liquid is 1-3% of the mass of the fermentation raw material, and/or the temperature of the composting fermentation is 50-60 ℃ for 7-15 days.

Further, the mass ratio of the humic acid to the sodium alginate is (30-40) to (10-15) to (6-8) to (2-5), and/or the temperature of the enzymolysis is 40-55 ℃ for 1-2 days.

Further, the mass ratio of the enzymolysis liquid to the microelement fertilizer to the composite regulating bacterial liquid is (90-100) to (2-4) to 1.

The compound regulating bacterial liquid consists of the following substances in parts by mass: 2 parts of bacillus megatherium liquid, 1 part of paenibacillus polymyxa liquid and 2 parts of lactobacillus plantarum liquid;

further, the temperature of the secondary fermentation is 40-50 ℃ and the time is 3-5 days.

The invention provides a method for improving the quality and yield of winter rape planted in saline-alkali soil, which is characterized in that the basis for applying different fertilizers in different periods is as follows:

The soil preparation and the base fertilizer application are carried out before 11 months of planting in the same year, the layered fertilization mode is adopted, the organic fertilizer is applied to the ground before the soil cultivation, the soil is turned over along with deep cultivation, and the ammonium bicarbonate, the calcium superphosphate, the potassium chloride and the boron fertilizer are applied to shallow soil layers during shallow cultivation. The layered fertilization mode can lead the fertilizer to be distributed more reasonably in the soil and meet the requirements of different growth stages of rape on nutrients. The organic fertilizer can improve the soil structure, increase the organic matter content of the soil and provide long-acting nutrients for the growth of the rape, and the ammonium bicarbonate, the superphosphate, the potassium chloride, the boron fertilizer respectively provide necessary elements such as nitrogen, phosphorus, potassium, boron and the like for the rape, promote the seedling growth of the rape and lay a foundation for the subsequent growth.

After seedling emergence, the rape grows rapidly, the requirement for nitrogen is increased, at the moment, urea can be applied in time to supplement nitrogen, the growth of rape seedlings is promoted, the number of leaves and the leaf area are increased, the photosynthesis efficiency is improved, the accumulation of more organic substances of the rape is facilitated, and a material foundation is provided for the later growth and yield formation. The straw fermentation biological fertilizer contains rich organic matters and beneficial microorganisms.

The organic matters are applied before overwintering, so that the soil structure of the saline-alkali soil can be improved, the soil porosity is increased, the water and fertilizer retention capacity of the soil is improved, the stress effect of the saline-alkali soil on rape root systems is relieved, a good soil environment is created for the growth of the rape root systems, and the absorption of the root systems to nutrients is facilitated. The beneficial microorganisms in the fertilizer can decompose organic substances in soil and release various nutrients such as nitrogen, phosphorus, potassium, medium trace elements and the like, so that the nutrient requirements of the rape growing in winter and spring in the next year are met. Meanwhile, the microbial activity can also adjust the balance of soil nutrients, so that adverse effects on the growth of rape caused by excessive or insufficient single nutrient are avoided. Microorganisms in the straw fermentation biofertilizer can promote the conversion of nitrogen in soil and reduce the accumulation of nitrate in the soil. Through the nitrification-denitrification of microorganisms, ammonium nitrogen in the soil is converted into nitrate nitrogen, and then part of the nitrate nitrogen is converted into nitrogen and released into the atmosphere, so that the nitrate content in the soil is reduced, the nitrate absorption of rape is reduced, and the nitrate content in the rape is reduced. The beneficial microorganisms in the fertilizer can generate growth regulating substances and secondary metabolites in the metabolic process, and the substances can stimulate physiological metabolism of rape plants, promote synthesis and accumulation of nutrient components such as vitamin C and the like, and improve the quality of rape.

The rapes enter the rapid growth and reproductive growth stages in spring of the next year, and the demand for nitrogen is greatly increased. At the moment, urea is applied to supplement nitrogen in time, so that the growth of rape stems and leaves, the differentiation of flowers and buds and the development of seeds are promoted, and the yield of rape is increased.

The invention has the beneficial effects that:

According to the invention, different fertilizers are scientifically and reasonably applied to winter rape in different periods, especially, the straw fermentation biological fertilizer is applied before overwintering, so that the method plays roles in improving the soil environment, regulating the soil nutrients, promoting nutrient absorption and conversion and the like, effectively reduces the nitrate content of winter rape, simultaneously improves the vitamin C content, improves the yield of rape, and achieves the purpose of improving the quality and the yield of winter rape planted in saline-alkali soil.

Detailed Description

Various exemplary embodiments of the invention will now be described in detail, which should not be considered as limiting the invention, but rather as more detailed descriptions of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In addition, for numerical ranges in this disclosure, it is understood that each intermediate value between the upper and lower limits of the ranges is also specifically disclosed. Every smaller range between any stated value or stated range, and any other stated value or intermediate value within the stated range, is also encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the application described herein without departing from the scope or spirit of the application. Other embodiments will be apparent to those skilled in the art from consideration of the specification of the present application. The specification and examples of the present application are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are intended to be inclusive and mean an inclusion, but not limited to.

In the embodiment of the invention, the parts are parts by weight unless special description is made.

The Lactobacillus plantarum liquid, the Bacillus subtilis liquid, the Trichoderma viride liquid, the Bacillus licheniformis liquid, the candida utilis liquid, the Bacillus megaterium liquid, the Paenibacillus polymyxa liquid and the Lactobacillus plantarum liquid required in the embodiments 1-3 are obtained by activating the purchased strains, inoculating the strains into a culture medium for expansion culture and fermenting, wherein the effective viable count of single strains in the mixed bacterial liquid after expansion culture and the composite regulating bacterial liquid is not lower than 3 hundred million/mL. The decomposed mixed bacteria liquid consists of 3 parts of lactobacillus plantarum liquid, 1.5 parts of bacillus subtilis liquid, 1 part of trichoderma viride liquid, 2 parts of thermophilic bacillus licheniformis liquid and 2 parts of candida utilis liquid in parts by mass, and the composite regulating bacteria liquid consists of 2 parts of bacillus megaterium liquid, 1 part of paenibacillus polymyxa liquid and 2 parts of lactobacillus plantarum liquid in parts by mass.

The straw used in examples 1-3 of the present invention was wheat straw.

Example 1 preparation method of straw fermented biofertilizer

Mixing crushed wheat straw and water according to a mass ratio of 3:1 to obtain fermentation raw materials, adding decomposed mixed bacteria liquid according to 1% of the mass of the fermentation liquid raw materials, adding water to adjust the water content of the materials to 50%, composting and fermenting for 7 days at 50 ℃ to obtain decomposed materials, adding starch plant waste residues, sodium humate and sodium alginate into the decomposed materials, wherein the mass ratio of the decomposed materials to the starch plant waste residues, the sodium humate to the sodium alginate is 30:10:8:3, uniformly mixing, adding a calcium carbonate solution to adjust the pH to 7.0, adding water to adjust the water content of the materials to 55%, performing enzymolysis for 1 day at 40 ℃ to obtain enzymolysis liquid, adding a trace element fertilizer and a compound adjusting bacteria liquid into the enzymolysis liquid, wherein the mass ratio of the enzymolysis liquid, the trace element fertilizer and the compound adjusting bacteria liquid is 90:4:1, adding water to adjust the water content of the materials to 60%, performing secondary fermentation for 5 days at 40 ℃, drying the secondary fermentation products until the water content is 5%, and preparing the granular straw fermentation biofertilizer through a granulator.

Example 2 preparation method of straw fermented biofertilizer

Mixing crushed wheat straw and water according to a mass ratio of 5:1 to obtain fermentation raw materials, adding decomposed mixed bacteria liquid according to 3% of the mass of the fermentation liquid raw materials, adding water to adjust the water content of the materials to 60%, composting and fermenting for 15 days at 60 ℃ to obtain decomposed materials, adding starch plant waste residues, sodium humate and sodium alginate into the decomposed materials, wherein the mass ratio of the decomposed materials to the starch plant waste residues, the sodium humate to the sodium alginate is 40:15:6:5, uniformly mixing, adding a calcium carbonate solution to adjust the pH to 7.0, adding water to adjust the water content of the materials to 50%, carrying out enzymolysis for 2 days at 55 ℃ to obtain enzymolysis liquid, adding a trace element fertilizer and a compound adjusting bacteria liquid into the enzymolysis liquid, wherein the mass ratio of the enzymolysis liquid, the trace element fertilizer and the compound adjusting bacteria liquid is 100:2:1, adding water to adjust the water content of the materials to 50%, carrying out secondary fermentation for 3 days at 50 ℃, drying the secondary fermentation products until the water content is 5%, and preparing the granular straw fermentation biofertilizer through a granulator.

Example 3 preparation method of straw fermented biofertilizer

Mixing crushed wheat straw and water according to the mass ratio of 4:1 to obtain fermentation raw materials, adding decomposed mixed bacterial liquid according to the mass ratio of 2% of the fermentation liquid raw materials, adding water to adjust the water content of the materials to 55%, composting and fermenting for 12 days at 55 ℃ to obtain decomposed materials, adding starch plant waste residues, sodium humate and sodium alginate into the decomposed materials, wherein the mass ratio of the decomposed materials to the starch plant waste residues, the sodium humate to the sodium alginate is 35:12:7:2, uniformly mixing, adding a calcium carbonate solution to adjust the pH to 7.0, adding water to adjust the water content of the materials to 60%, performing enzymolysis for 1 day at 40 ℃ to obtain enzymolysis liquid, adding a trace element fertilizer and a compound adjusting bacterial liquid into the enzymolysis liquid, wherein the mass ratio of the enzymolysis liquid, the trace element fertilizer and the compound adjusting bacterial liquid is 98:3:1, adding water to adjust the water content of the materials to 50%, performing secondary fermentation for 5 days at 45 ℃, drying the secondary fermentation products until the water content is 5%, and preparing granular straw fermentation biofertilizer through a granulator.

The land mass selected in the embodiments 4-6 of the invention has a pH value of below 9.2 and a salinity of 0.2-0.3g/kg;

among the fertilizers applied in examples 4 to 6 of the present invention, fertilizers other than straw-fermented biofertilizer were all commercially available.

Example 4a method for improving quality and yield of winter rape planted in saline-alkali soil,

The soil preparation and base fertilizer application are carried out before rape is planted in 11 months in the current year, a layered fertilization mode is adopted, namely, an organic fertilizer is applied to the ground before tilling, the organic fertilizer is turned over along with deep tilling, ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer are applied to shallow soil layers during shallow tilling, wherein the application amount of the organic fertilizer is 150 kg/mu, the application amount of the ammonium bicarbonate is 25 kg/mu, the application amount of the calcium superphosphate is 18 kg/mu, the application amount of the potassium chloride is 12 kg/mu, the application amount of the boron fertilizer is 0.9 kg/mu, the sowing amount of the direct seeding field mu is 400g, the urea is applied after emergence of seedlings, the application amount of the straw fermentation biofertilizer prepared in the embodiment 1 is applied for 15 days before winter, the application amount of the straw fermentation biofertilizer is 80 kg/mu, the last 3 months in the next year, the urea is applied for 13 kg/mu at 6-10cm height of the coating, and the harvesting time is 4 months.

During the period, weeding, pest control and watering irrigation before and after seeding and in seedling stage are carried out according to the conventional planting method.

Example 5a method for improving quality and yield of winter rape planted in saline-alkali soil,

The soil preparation and base fertilizer application are carried out before rape is planted in 11 months in the current year, a layered fertilization mode is adopted, namely, an organic fertilizer is applied to the ground before tilling, the organic fertilizer is turned over along with deep tilling, ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer are applied to shallow soil layers during shallow tilling, wherein the application amount of the organic fertilizer is 180 kg/mu, the application amount of the ammonium bicarbonate is 22 kg/mu, the application amount of the calcium superphosphate is 15 kg/mu, the application amount of the potassium chloride is 10 kg/mu, the application amount of the boron fertilizer is 1.0 kg/mu, the sowing amount of the direct seeding field mu is 400g, the urea is applied after emergence of seedlings, the application amount of the straw fermentation biofertilizer prepared in the embodiment 2 is 70 kg/mu, the last 3 months of the year is 10 kg/mu of urea at the height of 6-10cm, and the harvest is 4 months.

During the period, weeding, pest control and watering irrigation before and after seeding and in seedling stage are carried out according to the conventional planting method.

Example 6a method for improving quality and yield of winter rape planted in saline-alkali soil,

The soil preparation and base fertilizer application are carried out before rape is planted in 11 months in the current year, a layered fertilization mode is adopted, namely, an organic fertilizer is applied to the ground before tilling, and is turned over along with deep tillage, ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer are applied to shallow soil layers during shallow tillage, wherein the application amount of the organic fertilizer is 170 kg/mu, the application amount of the ammonium bicarbonate is 20 kg/mu, the application amount of the calcium superphosphate is 20 kg/mu, the application amount of the potassium chloride is 15 kg/mu, the application amount of the boron fertilizer is 0.8 kg/mu, the sowing amount of the direct seeding field mu is 400g, urea is applied after emergence of seedlings, the application amount of the straw fermentation biofertilizer prepared in the embodiment 3 is applied 10 days before winter, the application amount of the straw fermentation biofertilizer is 50 kg/mu, the last 3 months in the next year, the urea is 15 kg/mu at a height of 6-10cm, and the harvesting time is 4 months.

During the period, weeding, pest control and watering irrigation before and after seeding and in seedling stage are carried out according to the conventional planting method.

Comparative example 1

The method comprises the steps of preparing soil before rape is planted in 11 months in the current year and applying base fertilizer, applying the straw fermentation biological fertilizer prepared in the embodiment 1 to the ground before plowing, applying ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer to shallow soil layers during shallow plowing along with deep plowing, wherein the application amount of the organic fertilizer is 150 kg/mu, the application amount of the ammonium bicarbonate is 25 kg/mu, the application amount of the calcium superphosphate is 18 kg/mu, the application amount of the potassium chloride is 12 kg/mu, the application amount of the boron fertilizer is 0.9 kg/mu, the sowing amount of the direct seeding field is 400g, applying urea after emergence, applying the organic fertilizer for 15 days before winter, applying the urea for 13 kg/mu in the last 3 months of the year, and harvesting for 4 months.

Comparative example 2

The method comprises the steps of preparing soil before rape is planted in 11 months in the current year and applying base fertilizer, applying organic fertilizer to the ground before plowing, turning over with deep plowing, applying ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer to shallow soil layers during shallow plowing, wherein the application amount of the organic fertilizer is 150 kg/mu, the application amount of the ammonium bicarbonate is 25 kg/mu, the application amount of the calcium superphosphate is 18 kg/mu, the application amount of the potassium chloride is 12 kg/mu, the application amount of the boron fertilizer is 0.9 kg/mu, the sowing amount of the direct seeding field mu is 400g, urea is applied after emergence, the application amount is 8 kg/mu, the organic fertilizer is applied 15 days before winter, the application amount of the urea is 80 kg/mu, the next 3 months and the last ten days, the urea is applied at a height of 6-10cm, and the harvesting is carried out in 4 months.

Comparative example 3

Soil preparation and base fertilizer application are carried out before rape is planted in 11 months in the current year, organic fertilizer, ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer are mixed before farmland, then the mixture is spread on the ground, the mixture is turned over along with deep farmland, wherein the organic fertilizer is applied in an amount of 150 kg/mu, the ammonium bicarbonate is applied in an amount of 25 kg/mu, the calcium superphosphate is applied in an amount of 18 kg/mu, the potassium chloride is applied in an amount of 12 kg/mu, the boron fertilizer is applied in an amount of 0.9 kg/mu, the sowing amount of the direct seeding field is 400g, urea is applied after emergence, the application amount is 8 kg/mu, the straw fermentation biofertilizer prepared in the embodiment 1 is applied 15 days before winter, the urea is applied in an amount of 80 kg/mu, the last ten days of 3 months in the next year, the urea is applied in an amount of 13 kg/mu at a height of 6-10cm, and the harvesting is carried out in 4 months in the next year.

The nitrate and vitamin C contents in winter rape harvested in examples 4 to 6 and comparative examples 1 to 3 were measured by ultraviolet spectrophotometry and 2, 6-dichlorophenol titration methods, and the measurement results are shown in Table 1.

TABLE 1

As can be seen from Table 1, the fertilization method provided by the invention is applied to planting winter rape in saline-alkali soil, is beneficial to reducing the nitrate content of winter rape, and simultaneously improves the vitamin C content, thereby being beneficial to improving the quality of winter rape.

Measurement of winter rape yield the winter rape plants collected in examples 4-6 and comparative examples 1-3 were respectively filled into sealed bags and sealed, brought back to the laboratory, then washed with tap water to remove surface soil, quickly blotted with absorbent paper and the acre yield calculated as shown in Table 2.

TABLE 2

As can be seen from Table 2, the fertilization method provided by the invention is beneficial to improving the yield of winter rape in saline-alkali soil.

The above embodiments are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the claims of the present invention without departing from the design spirit of the present invention.

Claims (10)

1. A method for improving quality and yield of winter rape planted in saline-alkali soil is characterized by comprising the following steps of preparing soil and applying base fertilizer before rape is planted in 11 months in the same year, applying urea after emergence of seedlings, applying straw fermentation biofertilizer 10-15 days before overwintering, applying urea in spring of the next year and harvesting in 4 months of the next year.

2. The method for improving the quality and the yield of winter rape planted in saline-alkali soil according to claim 1, wherein the base fertilizer is applied by layered fertilization, the organic fertilizer is applied to the ground before the soil is cultivated, and ammonium bicarbonate, calcium superphosphate, potassium chloride and boron fertilizer are applied to shallow soil layers during shallow cultivation along with deep cultivation.

3. The method for improving the quality and the yield of winter rape planted in the saline-alkali soil according to claim 2, wherein the application amount of the organic fertilizer is 150-180 kg/mu, the application amount of the ammonium bicarbonate is 20-25 kg/mu, the application amount of the superphosphate is 15-20 kg/mu, the application amount of the potassium chloride is 10-15 kg/mu, and the application amount of the boron fertilizer is 0.8-1.0 kg/mu.

4. The method for improving the quality and the yield of winter rape planted in the saline-alkali soil according to claim 1, wherein the application amount of urea after emergence is 8-10 kg/mu, and the application amount of urea after spring of the next year is 10-15 kg/mu.

5. The method for improving the quality and the yield of winter rape planted in saline-alkali soil according to claim 1, wherein the application amount of the straw fermentation biofertilizer is 50-80 kg/mu.

6. The method for improving the quality and the yield of winter rape planted in saline-alkali soil according to claim 1, wherein the preparation method of the straw fermentation biofertilizer comprises the following steps:

Crushing straw and adding water to mix uniformly to obtain a fermentation raw material, inoculating a decomposed mixed bacterial liquid into the fermentation raw material, regulating the water content of the material to 50-60%, carrying out composting fermentation to obtain a decomposed material, adding waste residues of a starch mill, sodium humate and sodium alginate into the decomposed material, mixing uniformly, regulating the pH value of the mixture, regulating the water content of the material to 50-60% again, carrying out enzymolysis, adding a trace element fertilizer and a compound regulating bacterial liquid into the obtained enzymolysis liquid, regulating the water content of the material to 50-60%, carrying out secondary fermentation, drying the obtained secondary fermentation material, and granulating to obtain the straw fermentation biological fertilizer.

7. The method for improving the quality and the yield of winter rape planted in saline-alkali soil according to claim 6, wherein the mass ratio of the straw to the water is (3-5) to 1, and/or the decomposed mixed bacterial solution is 1-3% of the mass of the fermentation raw material, and/or the composting fermentation temperature is 50-60 ℃ and the time is 7-15 days.

8. The method for improving the quality and the yield of winter rape planted in the saline-alkali soil according to claim 6, wherein the mass ratio of the rotten clinker to the waste residues of the starch plant to the sodium humate to the sodium alginate is (30-40): (10-15): (6-8): (2-5), and/or the enzymolysis temperature is 40-55 ℃ for 1-2 days.

9. The method for improving the quality and the yield of winter rape planted in the saline-alkali soil according to claim 6, wherein the mass ratio of the enzymolysis liquid to the trace element fertilizer to the compound regulating bacterial liquid is (90-100) to (2-4) to 1.

10. The method for improving the quality and the yield of winter rape planted in saline-alkali soil according to claim 6, wherein the temperature of the secondary fermentation is 40-50 ℃ and the time is 3-5 days.