Method for returning corn straw, biochar and organic fertilizer to the field year by year and gradually deeper in thin black soil in Northeast China

Abstract

Method for returning corn straw, biochar and organic fertilizer to the gradually deepening soil year by year in the thin-layer black soil in Northeast China. It relates to a method for returning corn straw, biochar and organic fertilizer to the corn fields in the thin-layer black soil in Northeast China. The present invention is to solve the problem that the method of returning a single organic material year after year is not conducive to high-yield corn in the thin-layer black soil in Northeast China. The method includes: 1. Selecting land, planting and harvesting corn; 2. Returning the whole amount of corn straw to the field; 3. Preparing the land in spring of the second year, sowing corn, field management and harvesting; 4. Applying biochar; 5. Preparing the land in spring of the third year, sowing corn, field management and harvesting; 6. Applying organic fertilizer. This method gives full play to the ability of straw, biochar and organic fertilizer to improve soil fertility, and uses corn straw, biochar and organic fertilizer to improve soil fertility, thus facilitating the protection and utilization of the thin-layer black soil in Northeast China. The present invention belongs to the technical field of returning straw, biochar and organic fertilizer to the field.

Description

Technical Field

[0001] The present invention relates to a method for returning corn straw, biochar and organic fertilizer to the field in the thin-layer black soil corn fields in Northeast China. Background Art

[0002] Returning corn straw to the field can effectively increase the content of soil organic matter. Corn straw contains a large amount of mineral elements, such as carbon, phosphorus, potassium, etc., and also contains a large amount of organic matter such as cellulose, hemicellulose, lignin and protein. Therefore, returning corn straw to the field is considered an effective measure to increase soil organic matter and improve soil carbon and fertility. In recent years, it has been widely applied in the black soil areas of Northeast China. However, due to the cold climate in winter and spring in Northeast China, excessive amount of straw returned to the field may cause an increase in straw accumulation in the soil, reduce the straw decomposition process, and thus affect the growth and development of corn and the formation of yield. Thus, it can be seen that the more corn straw returned to the field is not necessarily better. In principle, it should ensure that the straw returned to the field in the current year is fully decomposed and does not affect the growth of the next crop, and determine the amount of corn straw returned to the field according to the actual situation. Biochar is a kind of carbon-rich substance with the characteristics of high aromatization and good stability. Returning biochar to the field can, on the one hand, reduce soil bulk density and increase soil pH value, which is beneficial to the growth of crop roots; on the other hand, returning biochar to the field can improve the fertilizer utilization efficiency. In addition, biochar can promote the atmosphere, soil circulation, terrestrial carbon storage, etc., so as to improve the natural balance of the soil carbon pool and increase the capacity of the soil carbon pool. Therefore, returning biochar to the field has been increasingly widely concerned. However, there are few literature reports on the suitable way of returning biochar to the field in the black soil area of Northeast China, and further research is still needed. Organic fertilizer has the characteristics of high yield and high nutrient content. Because returning it to the field can effectively improve the physical and chemical properties of the soil and enhance the fertility of cultivated land, it is considered the most green and environment-friendly fertilization raw material and the fertilization method that can best reflect circular agriculture, and is considered the "most suitable method for protecting black soil". However, deep plowing is required for returning organic fertilizer to the field, and there are few literature reports on the suitable way of returning organic fertilizer to the field in the thin-layer black soil area of Northeast China.

[0003] Returning corn straw, biochar and organic fertilizer to the field are all ideal methods for protecting the thin-layer black soil in Northeast China. However, due to the constraints of the characteristics of organic materials, the way of returning a single organic material (corn straw, biochar and organic fertilizer) to the field year after year is not conducive to the high yield of corn in the thin-layer black soil in Northeast China. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that the way of returning a single organic material (corn straw, biochar and organic fertilizer) to the field year after year is not conducive to the high yield of corn in the thin-layer black soil in Northeast China, and provides a method for gradually deepening the return of corn straw, biochar and organic fertilizer to the field in the thin-layer black soil in Northeast China year by year.

[0005] The method for gradually deepening the return of corn straw, biochar and organic fertilizer to the field in the thin-layer black soil in Northeast China year by year is as follows:

[0006] I. Field Selection, Maize Planting and Harvesting

[0007] In the spring of the first year, select a non-low-lying plot with a slope less than 5° in the thin black soil area of Northeast China. The tillage layer thickness in the spring of the first year (denoted as "H") ≤ 23 cm. According to the local farmers' habits, select spring maize varieties suitable for the local area for conventional sowing and field management, and harvest maize ears in the autumn according to the local farmers' habits.

[0008] II. Returning All Maize Straw to the Field

[0009] After harvesting maize ears, use a straw crusher to crush all the maize straw left in the field. The length of the crushed maize straw ≤ 15 cm. Evenly spread the crushed straw in the field, and then, with the help of plowing, turn the maize straw into the soil. The burial depth is 4 - 5 cm more than the tillage layer thickness in the spring of the first year (i.e., H + 4 cm ≤ burial depth ≤ H + 5 cm).

[0010] III. Land Preparation, Maize Sowing, Field Management and Harvesting in the Spring of the Second Year

[0011] In the spring of the second year, conduct land preparation in the field where maize straw has been buried, and according to the local farmers' habits, select spring maize varieties suitable for the local area for conventional sowing and field management. Harvest maize ears in the autumn according to the local farmers' habits, and after ear harvesting, all the maize straw is removed from the field.

[0012] IV. Application of Biochar

[0013] In the autumn of the second year, in the maize field where straw has been removed after ear harvesting, apply biochar. The biochar application rate is 0.13 - 0.33 t / mu. Evenly spread the biochar in the field, and with the help of harrowing, mix the biochar with the soil to a depth of the tillage layer thickness in the spring of the first year minus 5 cm (i.e., burial depth = H - 5 cm).

[0014] V. Land Preparation, Maize Sowing, Field Management and Harvesting in the Spring of the Third Year

[0015] In the spring of the third year, conduct land preparation in the field where harrowing has been carried out, and according to the local farmers' habits, select spring maize varieties suitable for the local area for conventional sowing and field management. Harvest maize ears in the autumn according to the local farmers' habits, and after ear harvesting, all the maize straw is removed from the field.

[0016] VI. Application of Organic Fertilizer

[0017] In the autumn of the third year, in the maize field where straw has been removed after ear harvesting, apply organic fertilizer. The application rate of organic fertilizer is 2 - 3 t / mu, and it is evenly spread in the field. With the help of deep plowing, turn it over and bury it. The burial depth is 8 - 10 cm more than the tillage layer thickness in the spring of the first year (i.e., H + 8 cm ≤ burial depth ≤ H + 10 cm).

[0018] The tillage layer thickness in the first spring described in Step 1 is 20 cm.

[0019] The burying depth described in Step 2 is 24 cm.

[0020] The organic fertilizer described in Step 6 is an organic fertilizer made from pig manure or cow manure as raw materials.

[0021] The present invention provides a method for returning corn straw, biochar, and organic fertilizer to the field year by year in a corn field on the thin-layer black soil in Northeast China, and thickening the tillage layer. By returning organic materials to the field to fertilize the soil, the tillage layer is also thickened, and the construction of a thick and fertile tillage layer on the thin-layer black soil in Northeast China can be achieved.

[0022] The advantages of the present invention over the prior art are as follows:

[0023] (1) This method gives full play to the ability of straw, biochar, and organic fertilizer to fertilize the soil, and fertilizes the soil with the help of corn straw, biochar, and organic fertilizer, thus facilitating the protection and utilization of the thin-layer black soil in Northeast China.

[0024] (2) The black soil in Northeast China is fertile, which is conducive to the growth of corn and the formation of corn yield. Therefore, both the biological yield and the grain yield of corn in the Northeast black soil area are relatively high. In other words, while obtaining a high yield of corn in the Northeast black soil, a large amount of corn straw is also produced. Returning corn straw to the field is an ideal method for protecting black soil. However, due to the limited hydrothermal resources in Northeast China, if the amount of straw returned to the field is too large, the straw returned to the field cannot decompose quickly, which will further affect the growth and development of corn and ultimately affect the formation of corn yield. Therefore, the large yield of corn straw and continuous returning to the field are important obstacle factors restricting the returning of corn straw to the field in the Northeast black soil area of China. This method pays attention to the objective fact that the large yield of corn straw in Northeast China and continuous full-amount returning to the field may lead to the growth and development of corn. In a three-year cycle, the corn straw is returned to the field in full amount once. Compared with continuous full-amount returning of straw to the field every year, the amount of straw returned to the field once is smaller, which can ensure that the straw decomposes fully within the three-year cycle, and thus ensure that the returning of straw to the field does not affect the growth and yield formation of corn.

[0025] (3) When returning straw to the field by deep burying, plowing operations are required. A large number of studies have shown that continuous plowing has high mechanical energy consumption, and continuous plowing makes the tillage layer soil loose. In the later growth stage of corn, if there are strong winds and heavy rains, lodging is very likely to occur, and ultimately affect the crop yield. In the method of the present invention, plowing is not carried out in the second year, and only harrowing operations are carried out. The corn growing on this tillage layer has stronger lodging resistance than the corn growing on the tillage layer with continuous plowing.

[0026] (4) The carbon-nitrogen ratio of corn straw itself is 65:1 to 85:1, while the carbon-nitrogen ratio suitable for soil microbial activity is 25:1 to 30:1. After returning corn straw to the field, it will cause a lack of nitrogen in the soil, resulting in competition for nitrogen between corn straw and soil microorganisms, affecting the growth of corn seedlings, and even causing yellowing and death of seedlings.

[0027] In the third year of this method, organic fertilizer is additionally applied. By virtue of the characteristics of the relatively low carbon-nitrogen ratio of organic fertilizer (such as the carbon-nitrogen ratio of pig manure is 11.5:1, and the carbon-nitrogen ratio of cow manure is 12.5:1), it can effectively supplement the unfavorable factor that the high carbon-nitrogen ratio of corn straw is not conducive to soil microbial activity, thereby creating favorable conditions for soil microbial activity.

[0028] (5) In the farmland of black soil in Northeast China, due to the traditional tillage method mostly using small machinery for operation, with many operation times and insufficient depth, a relatively thick plow sole is formed below the plow layer, and the plow layer of the soil is in a state of loose upper layer and solid lower layer, with poor permeability. The method of the present invention can deepen the plow layer year by year, thicken the plow layer, and effectively improve the adverse effect of the thickening of the plow sole. Specific implementation manners

[0029] The technical solution of the present invention is not limited to the following specific implementation manners listed, and also includes any combination between the specific implementation manners.

[0030] Specific implementation manner 1: The method for gradually deepening the return of corn straw, biochar and organic fertilizer to the field in the thin-layer black soil in Northeast China in this implementation manner is as follows:

[0031] I. Selecting land, planting and harvesting corn

[0032] In the spring of the first year, in the thin-layer black soil area in Northeast China, select a non-low-lying land plot with a slope less than 5° and a plow layer thickness (the plow layer thickness in the spring of the first year is denoted as "H") ≤ 23 cm in the spring of the first year. Select a spring corn variety suitable for the local area for conventional sowing and field management, and carry out corn ear harvesting in the autumn;

[0033] II. Returning the whole amount of corn straw to the field

[0034] After corn ear harvesting, all the corn straw left in the field is crushed with a straw crusher, and the length of the crushed corn straw ≤ 15 cm. The crushed straw is evenly spread in the field, and then with the help of tillage operation, the corn straw is turned into the soil, and the turning-in depth is 4 - 5 cm more than the plow layer thickness in the spring of the first year (that is, H + 4 cm ≤ turning-in depth ≤ H + 5 cm);

[0035] III. Land preparation, corn sowing, field management and harvesting in the spring of the second year

[0036] In the spring of the second year, the land where the corn straw has been buried is prepared for planting. Select spring corn varieties suitable for the local area for conventional sowing and field management. In the autumn, the corn ears are harvested, and all the corn straw is removed from the field after the ear harvest.

[0037] IV. Application of Biochar

[0038] In the autumn of the second year, in the corn field where the straw has been removed after the ear harvest, biochar is applied. The dosage of biochar is 0.13 - 0.33 t / mu. The biochar is evenly spread over the field and mixed with the soil by means of harrowing. The depth is the thickness of the plowed layer in the spring of the first year minus 5 cm (i.e., the burial depth = H - 5 cm).

[0039] V. Land Preparation, Corn Sowing, Field Management and Harvest in the Spring of the Third Year

[0040] In the spring of the third year, the land that has been harrowed is prepared for planting. Select spring corn varieties suitable for the local area for conventional sowing and field management. In the autumn, the corn ears are harvested, and all the corn straw is removed from the field after the ear harvest.

[0041] VI. Application of Organic Fertilizer

[0042] In the autumn of the third year, in the corn field where the straw has been removed after the ear harvest, organic fertilizer is applied. The dosage of the organic fertilizer is 2 - 3 t / mu, and it is evenly spread over the field and deeply plowed. The burial depth is 8 - 10 cm more than the thickness of the plowed layer in the spring of the first year (i.e., H + 8 cm ≤ burial depth ≤ H + 10 cm).

[0043] Specific Embodiment 2: The difference between this embodiment and Specific Embodiment 1 is that the thickness of the plowed layer in the spring of the first year described in Step 1 is 20 cm. Others are the same as Specific Embodiment 1.

[0044] Specific Embodiment 3: The difference between this embodiment and Specific Embodiment 1 or 2 is that the burial depth described in Step 2 is 24 cm. Others are the same as Specific Embodiment 1 or 2.

[0045] Specific Embodiment 4: The difference between this embodiment and any one of Specific Embodiments 1 to 3 is that the dosage of biochar described in Step 4 is 0.33 t / mu. Others are the same as any one of Specific Embodiments 1 to 3.

[0046] Specific Embodiment 5: The difference between this embodiment and any one of Specific Embodiments 1 to 4 is that the dosage of the organic fertilizer described in Step 6 is 3 t / mu. Others are the same as any one of Specific Embodiments 1 to 4.

[0047] Specific Embodiment 6: The difference between this embodiment and any one of Specific Embodiments 1 to 5 is that the organic fertilizer described in Step 6 is the organic fertilizer made from pig manure or cow manure as raw materials. Others are the same as any one of Specific Embodiments 1 to 5.

[0048] The following experiments were conducted to verify the effects of the present invention:

[0049] Experiment 1:

[0050] The method for returning corn straw, biochar, and organic fertilizer year by year and deeper layer by layer in the thin-layer black soil in Northeast China is as follows:

[0051] I. Site selection, corn planting, and harvesting

[0052] In the spring of the first year, in the thin-layer black soil area in Northeast China, a non-low-lying land plot with a slope less than 5° and a tillage layer thickness of 20 cm in the spring of the first year was selected. According to the local farmers' habits, a spring corn variety suitable for the local area was selected for conventional sowing and field management, and the corn ears were harvested in the autumn according to the local farmers' habits.

[0053] II. Full amount return of corn straw

[0054] After the corn ears were harvested, all the corn straw left in the field was crushed by a straw crusher, and the length of the crushed corn straw was ≤ 15 cm. The crushed straw was evenly spread in the field, and then with the help of plowing operation, the corn straw was turned into the soil with a turning-in depth of 24 cm.

[0055] III. Land preparation, corn sowing, field management, and harvesting in the spring of the second year

[0056] In the spring of the second year, land preparation was carried out in the field where the corn straw had been turned in, and according to the local farmers' habits, a spring corn variety suitable for the local area was selected for conventional sowing and field management. The corn ears were harvested in the autumn according to the local farmers' habits, and all the corn straw was removed from the field after the ear harvest.

[0057] IV. Application of biochar

[0058] In the autumn of the second year, in the corn field where the straw had been removed after the ear harvest, biochar was applied. The application rate of biochar was 0.33 t / mu. The biochar was evenly spread in the field, and with the help of harrowing operation, the biochar was mixed with the soil to a depth of 15 cm.

[0059] V. Land preparation, corn sowing, field management, and harvesting in the spring of the third year

[0060] In the spring of the third year, land preparation was carried out in the field where harrowing operation had been carried out, and according to the local farmers' habits, a spring corn variety suitable for the local area was selected for conventional sowing and field management. The corn ears were harvested in the autumn according to the local farmers' habits, and all the corn straw was removed from the field after the ear harvest.

[0061] VI. Application of organic fertilizer

[0062] In the autumn of the third year, in a cornfield where the straw was removed from the field after ear harvest, organic fertilizer was applied at a rate of 3 t / mu, and it was evenly spread in the field and incorporated into the soil by deep plowing. The plowing depth was 8 cm more than the plow layer thickness in the spring of the first year.

[0063] Compared with conventional tillage, the organic matter content in the plow layer soil of the present invention increases by more than 10%, and the plow layer thickness increases by 8 - 10 cm.

Claims

1. Method for returning corn straw, biochar and organic fertilizer to the field year by year and gradually deeper in the thin black soil in Northeast China, characterized in that The method for returning corn straw, biochar, and organic fertilizer to the thin-layer black soil in Northeast China year by year and gradually deeper is as follows: I. Field selection, corn planting, and harvesting In the spring of the first year, select non-low-lying land with a slope less than 5° and a tillage layer thickness ≤ 23 cm in the spring of the first year in the thin-layer black soil area of Northeast China. Select spring corn varieties suitable for the local area for conventional sowing and field management, and carry out corn ear harvesting in the autumn; II. Returning the whole amount of corn straw to the field After corn ear harvesting, all the corn straw left in the field is crushed by a straw crusher, and the length of the crushed corn straw ≤ 15 cm. The crushed straw is evenly spread in the field, and then with the help of plowing operation, the corn straw is turned into the soil, and the turning-in depth is 4 - 5 cm more than the tillage layer thickness in the spring of the first year; III. Land preparation, corn sowing, field management, and harvesting in the spring of the second year In the spring of the second year, carry out land preparation in the field where the corn straw has been turned in. Select spring corn varieties suitable for the local area for conventional sowing and field management, and carry out corn ear harvesting in the autumn. After ear harvesting, all the corn straw is removed from the field; IV. Application of biochar In the autumn of the second year, in the corn field where the straw has been removed after ear harvesting, apply biochar. The biochar dosage is 0.13 - 0.33 t / mu. The biochar is evenly spread in the field, and with the help of harrowing operation, the biochar is mixed with the soil to a depth of the tillage layer thickness in the spring of the first year minus 5 cm; V. Land preparation, corn sowing, field management, and harvesting in the spring of the third year In the spring of the third year, carry out land preparation in the field where harrowing operation has been carried out. Select spring corn varieties suitable for the local area for conventional sowing and field management, and carry out corn ear harvesting in the autumn. After ear harvesting, all the corn straw is removed from the field; VI. Application of organic fertilizer In the autumn of the third year, in the corn field where the straw has been removed after ear harvesting, apply organic fertilizer. The dosage of the organic fertilizer is 2 - 3 t / mu, and it is evenly spread in the field, and deep plowing is carried out with the help of deep plowing operation. The turning-in depth is 8 - 10 cm more than the tillage layer thickness in the spring of the first year.

2. The method for returning corn straw, biochar and organic fertilizer to the field year by year and gradually deeper in the thin-layer black soil in Northeast China according to claim 1, wherein The tillage layer thickness in the spring of the first year described in Step I is 20 cm.

3. The method for returning corn straw, biochar and organic fertilizer to the thin black soil layer in Northeast China year by year and gradually deeper according to claim 1, characterized in that The turning-in depth described in Step II is 24 cm.

4. The method for returning corn straw, biochar and organic fertilizer to the field year by year and gradually deeper in the thin-layer black soil in Northeast China according to claim 1, characterized in that The biochar dosage described in Step IV is 0.33 t / mu.

5. The method for returning corn straw, biochar and organic fertilizer to the thin black soil layer in Northeast China year by year and gradually deeper according to claim 1, characterized in that The dosage of the organic fertilizer described in Step VI is 3 t / mu.

6. The method for returning corn straw, biochar and organic fertilizer to the field year by year and gradually deeper in the thin-layer black soil in Northeast China according to claim 1, characterized in that The organic fertilizer described in Step VI is an organic fertilizer made from pig manure or cow manure as raw materials.