Dry land white slurry soil fertilizing method by coupling liquid fermentation cow dung and straw to return field

Abstract

The invention discloses a method for fertilizing dry land white slurry soil by coupling liquid fermentation cow dung and straw to return to field. The Baijiang soil fertilizing method provided by the invention comprises the following steps of: throwing crop straws and stubbles into the field in a full amount, then sowing liquid fermented cow dung, and turning over and burying soil; the liquid fermented cow dung dirt is a product obtained by anaerobic fermentation of cow dung, urine and colony house flushing sewage. According to the method, the liquid fermented cow dung and the straws are fully crushed and returned to the field to jointly fertilize the Baijiang soil, so that the cultivated land quality of the Baijiang soil can be remarkably improved, the straw decomposition and nutrient release rate can be accelerated, planting and breeding circulation and livestock and poultry manure resource utilization can be promoted, and the method has important significance on guaranteeing the national food safety.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil fertilizer and fertilization method, and particularly relates to a dry white clay soil fertilization method using liquid fermentation of cow manure and straw coupling and returning to field. BACKGROUND

[0002] White clay soil is a kind of soil formed by white slurry process on the parent material of slight inclination hillside in the temperate semi-humid and humid regions under the forest and meadow vegetation. White clay soil is generally divided into three layers: dark-colored humus surface layer (i.e. black soil layer, thickness of 0-20 cm), gray-white sub-surface layer-white clay layer (thickness of 20-40 cm) and dark brown sticky deposition layer. The profile configuration of white clay soil is Ah-E-Bt-C (or Cg or G).

[0003] White clay soil is one of the widely distributed cultivated soil resources in Heilongjiang Province, accounting for 10.07% of the total cultivated land area in the province. White clay soil has the characteristics of "sticky, lean, hard and acid", which causes frequent drought and flood disasters, nutrient deficiency, low number of microorganisms, restricted root growth, low fertilizer utilization and other problems, resulting in low and unstable crop yield of white clay soil, which is 20% lower than that of black soil in the same region. Therefore, white clay soil has been listed as a regional low-yield soil, and improving the quality of white clay soil is of great significance to improving regional grain yield and ensuring national food security.

[0004] Straw is a low-cost soil improvement material, and straw returning is a management measure for rational utilization of straw resources, which is beneficial to improving soil fertility and crop yield, such as CN106105468A and CN106916037A. However, the climate in Northeast China is cold in winter, with freeze-thaw cycle. After direct returning, the straw is slowly decomposed and cannot quickly provide nutrients. At the same time, the high carbon-nitrogen ratio of straw will also lead to a decrease in soil nitrogen supply capacity, affecting crop emergence, increasing diseases and pests, and increasing weeds and other problems. How to efficiently utilize straw and improve the effect of straw returning is one of the current technical problems in agricultural production.

[0005] Livestock and poultry manure contains more nitrogen than straw, and has a lower carbon-nitrogen ratio. Coupling with straw returning and application can promote straw decomposition, improve soil structure and nutrient status, and enhance water retention performance, thereby improving the productivity of farmland soil.

[0006] CN109121528A discloses a method for returning straw powder by spreading livestock and poultry manure, but the method is for black soil, which is significantly better than white clay soil in terms of properties. In addition, the livestock and poultry manure used in the method is solid livestock and poultry manure, which is easy to cause seedling burn and is not conducive to improving soil productivity.

[0007] Therefore, the present application is proposed. SUMMARY

[0008] The purpose of this invention is to provide a method for improving the fertility of albic soil, which addresses the prominent problems of low soil nutrient content, poor topsoil structure, poor straw return effect, and low utilization rate of livestock and poultry manure resources in albic soil agro-pastoral dryland areas.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention provides a method for improving the fertilization of alkaline soil, comprising the following steps: spreading all crop straw and stubble back into the field, then spreading liquid fermented cow manure, and finally turning over and burying the soil.

[0011] The liquid fermented cow manure is a product obtained through anaerobic fermentation of cow manure, urine, and wastewater from cow pens. It has the following characteristics: solids content ≤12%; pH 7.5–8.5; organic matter 2%–5%; total nitrogen (N) 0.2%–0.5%; total phosphorus (P₂O₅) 0.1%–0.3%; total potassium (K₂O) 0.4%–0.5%; available phosphorus 0.05%–0.2%; available potassium 0.2%–0.4%; ammonium nitrogen 0.05%–0.25%; nitrate nitrogen 0.05%–0.15%.

[0012] In this invention, the anaerobic fermentation is Nyssa anaerobic fermentation; the anaerobic fermentation time is at least 6 months; and the anaerobic fermentation temperature is -30℃ to 25℃.

[0013] In one specific embodiment, the preparation of the liquid fermented cow manure is carried out according to the following operation: First, cow manure, urine and pen flushing wastewater are transported to an anaerobic fermentation sealed storage tank (the top and bottom of the fermentation tank are covered with membranes) through service well pipelines and pumping systems for anaerobic fermentation treatment. The sediment at the bottom of the tank and the supernatant are thoroughly mixed through the stirring port. When applying, the liquid manure return machine is used to absorb it, mix it evenly again and spread it, so as to efficiently return it to the field as fertilizer.

[0014] In this invention, the application rate of the liquid fermented cow manure is 60–90 t·ha. -1 .

[0015] In this invention, the liquid fermented cow manure is applied before autumn land preparation.

[0016] In this invention, the liquid fermented cow manure is spread using either drip irrigation or injection. For arable land with a slope of <3°, drip irrigation is used; for arable land with a slope ≥3°, injection is used. Research has found that on arable land with a slope less than 3°, using a drip irrigation liquid manure application machine allows for perfect manure coverage by directly mixing the manure in the tank after absorption. If the arable land slope is ≥3°, a trenching injection manure spreader is used in conjunction to apply the manure in strips within the crop rows and directly cover it with soil to prevent the fermented cow manure from being lost.

[0017] In this invention, the length of the crop straw and stubble is ≤10cm, which serves to: 1) disrupt the growth environment of pests, as this method eliminates the need for spreading insect-resistant microbial powder preparations, significantly reducing costs; 2) maintain soil aeration and water permeability; 3) facilitate subsequent manual or mechanical operations; and 4) promote rapid rise in soil temperature in spring.

[0018] In one specific embodiment, the crop straw and stubble are crushed and spread using a combine harvester equipped with a straw crushing device, eliminating the need for gathering and then tilling. This method is more effective in improving the drought and waterlogging resistance of albic soil, and can uniformly improve soil structure, aeration, water permeability and fertilizer retention capacity throughout the entire tillage layer, thereby improving the overall drought and waterlogging resistance of albic soil.

[0019] In this invention, the soil is tilled to a thickness of 25-30 cm, and then harrowed and ridged without compaction. The advantages of this method are mainly: First, the tillage depth reaches the depth of the silty soil layer, resulting in better improvement of the silty soil; second, the absence of compaction reduces the negative environmental impact of mechanical operation fuel combustion and emissions, while maintaining soil looseness and preserving the aeration and permeability of the silty soil.

[0020] In this invention, the soil is turned over and buried within 24 hours after the liquid fermented cow manure is spread.

[0021] In this invention, the albic soil is soil from the agro-pastoral dryland region of Northeast China, with an organic matter content ranging from 6 to 10 g / kg. -1 .

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0023] 1. This invention uses cow manure as a substitute for the commonly used pig manure. It takes advantage of the high release rate and high organic matter content of cow manure to better improve the soil structure of albic soil. Furthermore, albic soil is acidic, and the organic acids in cow manure help to neutralize the soil acidity. In addition, cow manure accounts for the highest proportion of manure resources in Heilongjiang Province. The rational use of cow manure resources is more in line with the goal of improving the economic benefits of traditional planting industry and promoting the green and healthy development of planting and breeding industries through crop-livestock cycles.

[0024] 2. The liquid fermented cow manure of this invention is a product obtained by anaerobic fermentation of cow manure, urine, and sewage from the pens for more than six months, followed by harmless treatment. Compared with solid livestock and poultry manure, it can moisten straw and accelerate straw decomposition. Therefore, no decomposition microbial agents are added, reducing costs. Through the activity of anaerobic microorganisms (such as methanogens and lactic acid bacteria), organic matter is decomposed into gases such as methane and carbon dioxide, producing biogas that can be used as a renewable energy source, reducing the degree of environmental pollution.

[0025] The resulting liquid fermented cow manure has the following advantages: low solids content, less likely to burn seedlings; thorough fermentation, reducing the content of harmful substances; complete nutrient retention, high nutrient release rate, improving fertilizer utilization; effective utilization of urine and manure resources in addition to solid manure, improving the utilization rate of livestock and poultry manure resources and reducing environmental pollution; low selling price, reducing planting costs, etc.

[0026] 3. Compared with traditional solid manure or biogas slurry, this invention couples liquid fermented cow manure with deep plowing of straw for return to the field. It can accelerate the decomposition of straw by using liquid fermented cow manure, increase the nutrient release rate of straw, help increase the organic matter and readily available nutrient content of albic soil, and improve the problems of poor aeration and permeability caused by the dense structure of albic soil, such as poor drought and flood resistance, low total nutrient storage, and low organic matter content. Ultimately, it increases yield by increasing the 100-grain weight and the number of grains per ear of crops, thus achieving the goal of simultaneously improving fertilizer utilization and economic benefits.

[0027] 4. The fertilization method provided by this invention can also avoid the problems of seedling burn or low nutrient utilization caused by traditional solid cow manure, as well as the waste of resources and environmental pollution caused by large urine output and difficulty in returning it to the field. It is of great significance for crop-livestock cycle, improving the economic benefits of traditional planting industry, and promoting the green and healthy development of planting and breeding industry. At the same time, the direct return of all straw to the field can significantly improve its utilization rate. Attached Figure Description

[0028] Figure 1 The process flow diagram of the fattening method provided by the present invention.

[0029] Figure 2 The decomposition rate of corn stalks.

[0030] Figure 3 The nutrient release rate of corn stalks.

[0031] Figure 4 Comparison of harvest yields from field demonstration trials. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0033] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0034] Unless otherwise specified, all reagents, materials, instruments, etc. used in the following examples are commercially available.

[0035] The liquid fermented cow manure used in the following examples was taken from an anaerobic fermentation sealed storage tank at a dairy farm.

[0036] The anaerobic fermentation sealed storage bladder is a fermentation tank with a membrane covering both the top and bottom to form a bladder-type fermentation. It is also equipped with a service well (for manure input and output operations), a stirring port (to fully mix the sediment at the bottom of the tank with the supernatant to achieve a homogeneous state before returning it to the field), an exhaust device (to allow waste gas to be discharged during sealed storage), and a drainage system for the covering layer.

[0037] The specific preparation process of the liquid fermented cow manure includes: firstly, cow manure, urine, and wastewater from the pen are transported to an anaerobic fermentation sealed storage tank through service well pipes and a pumping system for anaerobic fermentation treatment. The manure must be stored in a sealed tank for more than 6 months to allow the manure in the tank to ferment at low temperature in an anaerobic environment to achieve harmless treatment and reduce the volatilization of ammonia nitrogen; then, the sediment at the bottom of the tank is thoroughly mixed with the supernatant through a stirring port to obtain the final product.

[0038] The liquid fermented cow manure has the following characteristics: solids content ≤12%; pH 7.5–8.5; organic matter 2%–5%; total nitrogen (N) 0.2%–0.5%; total phosphorus (P2O5) 0.1%–0.3%; total potassium (K2O) 0.4%–0.5%; available phosphorus 0.05%–0.2%; available potassium 0.2%–0.4%; ammonium nitrogen 0.05%–0.25%; nitrate nitrogen 0.05%–0.15%.

[0039] In practical application, the liquid manure is absorbed by a liquid manure return machine, stirred evenly again, and then spread, serving as an efficient fertilizer for return to the field.

[0040] Example: Fertilization method of alkaline soil

[0041] Taking the albic soil of the agro-pastoral transition dryland area in Northeast China as an example, such as Figure 1 As shown, the method for fertilizing alkaline soil is as follows:

[0042] (1) Detect the organic matter content of the soil to be fertilized;

[0043] (2) When harvesting autumn crops, use a combine harvester with a straw crushing device to crush crop straw and stubble to a length of ≤10cm and spread it on the soil surface to achieve full direct return to the field.

[0044] (3) Before autumn land preparation, spread the liquid fermented cow manure evenly on the soil surface, turn it over and cover it to 30cm within 24 hours, rake it flat and then make ridges.

[0045] The liquid fermented cow manure is applied by drip irrigation or injection.

[0046] If the slope of the arable land is less than 3°, use drip irrigation for spreading;

[0047] If the slope of the cultivated land is ≥3°, use injection-type spreading.

[0048] After the above-mentioned fertilization treatment, the alkaline soil can be sown normally in the following spring and field fertilization and weeding management can be carried out.

[0049] Experiment 1: Pot Experiment on Straw Decomposition Characteristics

[0050] A pot experiment on straw decomposition was conducted using nylon mesh bags.

[0051] The tested soil was a typical albic soil (0-30 cm), taken from the experimental station of the Agricultural Technology Extension Center of 852 Farm, Shuangyashan City, Heilongjiang Province (132°63′E, 46°23′N).

[0052] Planting pattern: Two-year continuous corn cropping.

[0053] Before the experiment, the basic soil fertility of the black soil layer in the albic soil was: organic matter 9.86 g·kg⁻¹ -1 Alkaline nitrogen content: 116 mg / kg -1 Available phosphorus 8.24 mg·kg -1 Available potassium 138.54 mg·kg -1 pH 6.2, bulk density 1.520 g·cm³ -3 .

[0054] The experiment used two organic materials: liquid fermented cow manure and solid cow manure. Both were thoroughly mixed with the soil. Three application gradients were set for each material, resulting in a total of five treatments.

[0055] ① Blank control (no organic materials or chemical fertilizers applied, CK);

[0056] ② 15 t·hm of solid cow manure -2 (S, based on field research, is the commonly used quantity);

[0057] ③ Liquid fermentation of cow manure 30t·hm -2 (D1);

[0058] ④ Liquid fermentation of cow manure 60t·hm -2 (D2);

[0059] ⑤ Liquid fermentation of cow manure 90t·hm -2(D3, based on previous research, represents the safe threshold for black soil application).

[0060] Table 1 shows the main physicochemical properties of liquid fermented cow manure and solid cow manure.

[0061] Table 1 Main Properties of Organic Materials

[0062]

[0063] Each treatment was repeated three times, meaning that three basins were set up for each treatment for sampling and analysis.

[0064] Soil samples were taken from the black soil layer in the field and sieved through a 5mm standard aperture sieve. The samples were then placed into ordinary plastic flowerpots (12cm bottom diameter, 18cm inner diameter, and 18cm height), with 2kg of soil per pot. A nylon mesh bag method was used for burying the soil. Corn stalks were cut into 3-5cm pieces, air-dried, and then mixed with the black soil layer soil at a straw-to-soil ratio of 0.35% (total straw return to the field). The mixture was then placed into mesh bags (10cm x 15cm, 1mm aperture) and sealed tightly. The mesh bags were placed 5cm below the soil surface. One bag was buried per pot, with each bag containing 6.91g of straw (total straw return to the field is 10500kg·hm²). -2 ).

[0065] The experiment began on October 15, 2023, with potted plants placed outdoors to simulate a field environment. Destructive sampling was conducted at 30, 60, 90, 120, 150, and 180 days after the start of the experiment.

[0066] Test items and methods:

[0067] After removing the mesh bags, rinse off any soil, roots, and other contaminants adhering to the surface with distilled water. Then, rinse the mesh bags thoroughly three times with distilled water. Place them in an oven and dry at 85°C until constant weight. Weigh the dry weight of the straw, then crush and sieve it for later use. The total carbon content of the straw was determined using the potassium dichromate titration method; the total nitrogen and total phosphorus content of the straw was determined using an AA3 flow analyzer; and the total potassium content of the straw was determined using a flame photometer.

[0068] The straw decomposition rate and nutrient release rate are calculated using the following formulas:

[0069] Straw decomposition rate = (M0 - M) t )×100% / M0

[0070] Nutrient release rate = (M0C0-M) t C t ) / M0C0×100%

[0071] In the formula:

[0072] M0 represents the dry weight of added straw, in grams.

[0073] M t The dry weight of straw at a decomposition time of t is expressed in grams.

[0074] t represents the decomposition time, expressed in days (d).

[0075] C0 represents the original nutrient content of straw, measured in g·kg⁻¹. -1 ;

[0076] C t The nutrient content of straw at a decomposition time t is expressed in g·kg. -1 .

[0077] Experimental results:

[0078] Depend on Figure 2 It is evident that the application of medium and high amounts of liquid fermented cow manure significantly improved the decomposition rate of corn stalks in alkaline soil compared to the CK and solid cow manure treatments, and the rate increased with increasing application amount. The D3 treatment reached its maximum decomposition rate at each stage, increasing by 43.32%, 17.55%, 13.23%, and 3.04% compared to the CK, S, D1, and D2 treatments, respectively, after 180 days.

[0079] Depend on Figure 3 It is evident that the application of organic materials can significantly increase the release rate of various nutrients from corn stalks in alkaline soil. The release rates of carbon, nitrogen, phosphorus, and potassium under different treatments are D3 > D2 > S > D1 > CK, with all reaching their maximum values ​​in the D3 treatment.

[0080] Experiment 2: Experiment on the effect of alkaline soil improvement in residential areas

[0081] A plot-based field experiment was established on October 29, 2022, at the Experimental Station of the Agricultural Technology Extension Center of Farm 852 (132°63′E, 46°23′N). The test soil was typical albic soil (basic soil physicochemical properties are shown in Table 2). The planting pattern for 2023-2024 was continuous maize cropping, with the tested maize variety being Songyu 438, and a planting density of 75,000 plants per hectare. -2 .

[0082] Table 2 Basic physicochemical properties of the tested soils

[0083]

[0084] The experiment used a completely randomized experimental design with a total of 5 treatments:

[0085] ① Conventional fertilization on the farm (using only chemical fertilizers, F);

[0086] ② 15 t·hm of solid cow manure -2 (S, based on field research, is the commonly used quantity);

[0087] ③ Liquid fermentation of cow manure 30t·hm-2 (D1);

[0088] ④ Liquid fermentation of cow manure 60t·hm -2 (D2);

[0089] ⑤ Liquid fermentation of cow manure 90t·hm -2 (D3, based on previous research, represents the safe threshold for black soil application).

[0090] Each treatment was repeated three times, for a total of 18 plots. Each plot consisted of 8 rows, with a length of 6m, a width of 5.2m, and an area of ​​31.2m². 2 The community has two rows of strips on the left and right, and 1 meter wide sidewalks on both sides.

[0091] A combine harvester equipped with a straw crushing device is used to crush the previous crop (corn) straw and stubble to a length of ≤10cm, and then spread it on the soil surface to achieve full direct return to the field. Organic materials are applied manually as base fertilizer in the plot after the straw has been fully returned to the field in autumn. Then, a tractor-pulled hydraulic reversible plow is used to plow the straw and organic materials together to a depth of 30cm, and then the soil is harrowed and ridged.

[0092] The following year, precision mechanical sowing and fertilization (N: 90 kg·hm²) were carried out during the sowing period. -2 P2O5: 72 kg·hm -2 K2O: 72 kg·hm -2 Apply topdressing fertilizer (N: 138 kg·hm²) during the topdressing period. -2 In the CK treatment, the fertilizer was removed after each application. Weeding and pest control were carried out in accordance with local farmers' practices.

[0093] Test items and methods:

[0094] In 2024, after the crop harvest, samples of black soil and white soil were collected from each plot using the "S" five-point method. After removing dead leaves, gravel and roots from the soil surface, the soil was air-dried and sieved for the determination of soil physicochemical properties.

[0095] Soil bulk density was determined and calculated using the ring sampler method; compaction was measured using a compaction meter; organic matter content was determined using the potassium dichromate volumetric method; alkaline nitrogen content was determined using the alkaline diffusion method; available phosphorus content was determined using 0.5 mol·L⁻¹. -1 NaHCO3 extraction-molybdenum antimony scandium colorimetric method for determination; available potassium was determined using 1 mol·L⁻¹. -1 Ammonium acetate extraction-flame photometry determination. 5m from the center of each plot. 2 Harvest all the corn, dry it, thresh it, and weigh it. Take 10 ears of corn with uniform growth for seed testing, observe the number of kernels per ear, the weight of 100 kernels, and calculate the grain yield (14% moisture content).

[0096] Experimental results:

[0097] Table 3 Soil bulk density and compaction under different treatments

[0098]

[0099] Note: The values ​​in the figure are averages, n=3. Different lowercase letters indicate differences in values ​​between different treatments (P<0.05).

[0100] As shown in Table 3, compared with the initial values, the bulk density and compaction of the soil after treatments F, S, D1, D2, and D3 all decreased. Among them, the application of liquid fermented cow manure (D1, D2, D3) improved the physical properties of the albic soil better than solid cow manure (S), and the improvement effect increased with the increase of the application amount (D2, D3). The bulk density and compaction of the soil in treatment D3 were the lowest.

[0101] Table 4 Soil nutrient content under different treatments

[0102]

[0103] Note: The values ​​in the figure are averages, n=3. Different lowercase letters indicate differences in values ​​between different treatments (P<0.05).

[0104] As shown in Table 4, soil organic matter, alkaline nitrogen, available phosphorus, and available potassium were improved after the organic material coupled with straw deep plowing and returning to the field treatment compared with the CK and F treatments. The order of improvement under different treatments was D3 > D2 > S > D1 > F, with all reaching the maximum value in the D3 treatment.

[0105] Table 5. Maize yield, its components, and economic benefits under different treatments.

[0106]

[0107] Note: Values ​​in the figure are averages, n=3. Different lowercase letters indicate differences in values ​​between different treatments (P<0.05). Input costs (fertilizer costs only): urea 2.80 yuan / kg; diammonium phosphate 4.05 yuan / kg; potassium chloride 3.08 yuan / kg; liquid fermented cow manure 19 yuan / ton; solid cow manure 320 yuan / ton. The price of corn with 14% moisture content was 2.30 yuan / kg. The yield increase rate was compared to the conventional treatment with the organic material treatment.

[0108] As shown in Table 5, deep plowing and returning organic materials and straw to the field increased corn yield and its components. The yield of liquid fermented cow manure was higher than that of conventional fertilization and solid cow manure treatments, reaching a maximum of 11.11 t·hm under treatment D3. -2 Compared to treatments F and S, the yield increased by 13.38% and 2.30%, respectively. The yield-to-income ratio reached its maximum of 25,558 yuan / hm² under treatment D2.-2 The profit reached its maximum of 21,630 yuan / hm under treatment D1. -2 .

[0109] Experiment 3: Field Demonstration Yield Comparison Experiment

[0110] On October 17, 2023, a 200-mu (132°53′E, 46°21′N) field control demonstration experiment was conducted at the Fifth Branch of the 852 Farm. The soil used was typical albic soil, the maize variety used was Songyu 438, and the planting density was 75,000 plants per hectare. -2 .

[0111] The experimental treatment was as follows:

[0112] ① Control treatment: Conventional fertilization on the farm (only chemical fertilizer was applied, and the straw was fully returned to the field and plowed to a depth of 25cm);

[0113] ②Optimized treatment: Use a combine harvester with a straw crushing device to crush the straw and stubble of the previous crop (corn) to a length of ≤10cm, spread it on the soil surface and then plow it to a depth of 30cm to achieve full direct return to the field.

[0114] Subsequently, a drip-type liquid manure return machine was used to extract the liquid fermented cow manure and mix it evenly inside the tank before applying it to the soil at a rate of 90 t·hm². -2 Then, a tractor-trailer with a hydraulic reversible plow was used to till the straw and organic materials together to a depth of 30cm, followed by harrowing and ridging. The following year, precision mechanical sowing and fertilization (N: 90kg·hm²) were carried out. -2 P2O5: 72 kg·hm -2 K2O: 72 kg·hm -2 Apply topdressing fertilizer (N: 138 kg·hm²) during the topdressing period. -2 Weeding and pest control in the fields are carried out in accordance with the local farmers' habits.

[0115] Experimental results:

[0116] Depend on Figure 4 It can be seen that the optimized treatment yield in the field demonstration experiment was 11.04 t·hm. -2 The yield increased by 7.07% compared to the control treatment.

[0117] The above experimental results show that deep plowing and returning liquid fermented cow manure to a depth of 30cm in combination with straw has a good effect on improving albic soil. It can increase the straw decomposition rate and nutrient release rate, reduce the bulk density and compaction of albic soil, and increase the content of organic matter, available nitrogen, available phosphorus, and available potassium in both the black soil and albic layers of albic soil. This significantly improves soil fertility and ultimately increases harvest yield and economic benefits. Based on a comprehensive analysis of fertilization effects and economic benefits, an organic matter content of 6–10 g / kg is recommended for albic soil.-1 In some areas, the application rate of liquid fermented cow manure is 60–90 t·hm. -2 .

[0118] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for improving the fertility of alkaline soil, characterized in that, All crop straw and stubble were spread back to the field, followed by the application of liquid fermented cow manure, and then the soil was turned over and buried. The liquid fermented cow manure waste is a product obtained by anaerobic fermentation of cow manure, urine and wastewater from the pens. The liquid fermented cow manure waste has the following characteristics: Solid content ≤12%; pH 7.5–8.5; Organic matter 2%–5%; Total nitrogen, expressed as N, is 0.2%–0.5%. Total phosphorus, calculated as P2O5, is 0.1%–0.3%; Total potassium, calculated as K2O, is 0.4%–0.5%; Available phosphorus: 0.05%–0.2%; Available potassium: 0.2%–0.4%; Ammonium nitrogen: 0.05%–0.25%; Nitrate nitrogen: 0.05%–0.15%.

2. The fattening method according to claim 1, characterized in that, The anaerobic fermentation is Nangial anaerobic fermentation; The anaerobic fermentation process takes at least 6 months; The anaerobic fermentation temperature is -30℃ to 25℃.

3. The fattening method according to claim 1 or 2, characterized in that, The application rate of the liquid fermented cow manure is 60-90 t·ha. -1 .

4. The fattening method according to claim 1 or 2, characterized in that, The liquid fermented cow manure was applied before autumn land preparation.

5. The fattening method according to claim 1 or 2, characterized in that, The liquid fermented cow manure is spread using either drip irrigation or injection.

6. The fattening method according to claim 5, characterized in that, For cultivated land with a slope of <3°, the drip irrigation method is used for spreading the albic soil; for cultivated land with a slope of ≥3°, the injection method is used for spreading the albic soil.

7. The fattening method according to claim 1 or 2, characterized in that, The length of the crop straw and stubble is ≤10cm.

8. The fattening method according to claim 1 or 2, characterized in that, The soil layer thickness is 25-30cm.

9. The fattening method according to claim 1 or 2, characterized in that, The soil should be turned over and buried within 24 hours after the liquid fermented cow manure is spread.

10. The fattening method according to claim 1 or 2, characterized in that, The albic soil mentioned is from the agro-pastoral dryland area of ​​Northeast China, and its organic matter content ranges from 6 to 10 g·kg⁻¹. -1 .

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