Method for improving severe saline-alkali soil planting paddy field by pre-burying straw

Abstract

The invention discloses a method for improving a severely saline-alkali soil planting paddy field by pre-burying straws, which increases the soil porosity and prevents the salinity from rising through a straw returning mode that crops are not planted in the current year after straws are turned over and crops are planted on the soil in the next year. Meanwhile, the straws containing a large amount of nitrogen, phosphorus, potassium and various medium and trace nutrient elements are fully rotted and then are used for planting crops, so that nutrients in the straws are fully and effectively utilized. According to the method, on one hand, organic matter in the straw is helped to be fully returned to soil, the soil fertility is improved, and meanwhile, the problems that saprophytic microorganisms compete for nutrients and water resources with crops in the straw degradation process are solved; on the other hand, the soil structure can be improved, the porosity and the permeability can be increased, salt and alkali ions are prevented from moving to surface soil, the problem that crops in the paddy field in severe saline-alkali soil grow slowly is solved, and the remarkable soil improvement effect is achieved by combining the two effects. The method is simple to operate, easy to popularize and good in later economic benefit.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali farmland improvement, in particular to a method for improving paddy fields in severe saline-alkali land by pre-burying straws. Background Art

[0002] Northeast China is the main production base of high-quality commercial japonica rice in northern my country. Its low-yield paddy fields are mainly distributed in the saline-alkali rice area in western Jilin Province. The paddy field soil in this area is mainly soda saline-alkali soil. Compared with other types of soil, it not only has poor physical and chemical properties and structure, but also covers a large area. Relevant data surveys show that the area of ​​soda saline-alkali paddy fields with different salinity levels in the western rice area of ​​Northeast China is nearly one million hectares, accounting for about 35% of the total rice planting area in Northeast China. Soda saline-alkali soil has disadvantages such as high pH value, high salt content, high alkalinity, and strong dispersion, which seriously affect the growth and development of crops, resulting in a significant decline in crop yield and quality. At present, the improvement methods of soda saline-alkali paddy fields are mainly divided into three measures: (1) physical improvement: such as drainage and salt washing, establishment and improvement of paddy field irrigation and drainage engineering system, etc.; (2) chemical improvement: balanced fertilization and farmyard manure, etc.; (3) biological improvement: breeding salt-tolerant and high-yield rice varieties, pot-grown seedlings, dense planting, disease, insect and weed control, etc.

[0003] As an important reserve arable land resource, the rational development and efficient utilization of saline-alkali land are of great significance to the security of grain reserves in China and even the world. The restoration of saline-alkali land needs to be adapted to local conditions and develop improvement technologies suitable for local climate, soil and terrain conditions. The western part of Northeast China is located in the interlaced area of ​​agriculture and animal husbandry, and is rich in straw resources. Straw, as an important by-product in agricultural production, contains a large amount of organic matter and nutrients such as nitrogen, phosphorus, potassium, and trace elements after decomposition, which can be directly absorbed and utilized by crops. Therefore, returning straw to the field as a highly efficient and environmentally friendly farming method can not only reduce soil bulk density and stabilize soil structure, but also increase soil organic carbon content, promote biological fixation of soil inorganic nitrogen, maintain or improve soil fertility, improve soil physical, chemical and biological properties, promote crop growth and increase yields.

[0004] At present, most of the improvement using straw is mainly for dry fields, such as "A method for rapid construction of soda saline-alkali dry fields", which improves dry field soil by adding a large amount of straw at one time. However, there are two problems in returning straw to paddy fields: one is that the straw has a low specific gravity and is easy to float on the water surface, affecting the growth of rice; the other is that there is clear water on the surface of the paddy field, and the toxic and harmful substances produced during the straw decay process are extremely harmful to crops. In "A comprehensive planting method for increasing carbon, oxygen and resistance of rice in soda saline-alkali land", the stubble of paddy rice straw is returned to the field for carbon increase, but the amount of return is low, and the decay process of straw will affect the growth of crops in the current year due to competition for water and nutrients. Therefore, if 30 to 40 tons of straw are added per hectare in the paddy field according to this method, rice will not be able to grow at all. In addition, the decomposition process of returning straw to the field may be slow and affect the soil moisture. Based on the above, there is an urgent need to develop a method of pre-burying straw to improve paddy fields in severely saline-alkali land, so that paddy field crops can absorb sufficient nutrients from the soil, which is beneficial to their own development and thus increases regional grain production. Summary of the invention

[0005] The purpose of the invention is to provide a method for improving paddy fields in severe saline-alkali land by pre-burying straws, so as to solve the technical problems of slow growth and low yield of paddy field crops in severe saline-alkali land.

[0006] To achieve its purpose, the present invention adopts the following technical solution: The present invention provides a method for improving paddy fields in severe saline-alkali land by pre-burying straw, comprising the following steps: Step 1: Collect straw: Use a transport vehicle to collect straw in the autumn of the year before the growing season or in the spring of the current year; Step 2: Crush the straw: crush the straw to a length of 5-8 cm by a harvester; Step 3: Straw covering: Use a forklift to evenly spread the crushed straw on the land. There is no visible water to prevent the straw from floating in the water after being covered; Step 4: Spraying the straw decomposing agent: spraying the straw decomposing agent onto the surface of the straw; Step 5: Mix the straw and soil: Use a rotary tiller to mix the crushed straw and saline-alkali soil evenly. The tillage depth is 25-30 cm; Step 6: Secondary promotion of rot: In August of the same year, use a rotary tiller again to mix the unrotten straw on the surface with the saline-alkali soil, with a rotary tillage depth of 25-30 cm; Step 7: Fertilization and irrigation: In the spring of the second year, fertilize and drain and wash away the salt 2 to 3 times; Step 8. Transplanting: In mid-to-late May, plant the paddy field crop seedlings in the paddy fields in an orderly manner.

[0007] As a further preferred embodiment of the technical solution of the present invention, in step 1, the straw is rice straw.

[0008] Furthermore, in step three, the amount of straw laid is 30-40 t / ha.

[0009] Furthermore, in step 4, the straw decomposing agent is sprayed at a rate of 35 kg / ha.

[0010] Furthermore, the straw decomposing agent is a high-enzyme organic fast-decomposing agent produced by Anhui Richland Biotechnology Co., Ltd.

[0011] Furthermore, in step seven, the fertilization scheme is to apply 200 kg / ha of N during the entire growth period, and the type of fertilizer is compound fertilizer (14-16-15).

[0012] Furthermore, in step eight, the paddy field crop is rice.

[0013] By adopting the above technical solution, the present invention achieves the following beneficial effects: 1. Promote the growth rate of paddy field crops in severe saline-alkali land and increase crop yield.

[0014] The applicant has found through research that if crops are not planted in the year after the straw is plowed, but crops are planted on the soil in the second year, the soil porosity can be increased to avoid the increase of salt. At the same time, the straw contains a large amount of nitrogen, phosphorus, potassium and various trace nutrients. Therefore, the nutrients in the straw can be fully and effectively utilized after the straw is fully rotted before planting crops. Therefore, the present invention uses a method of planting paddy field crops after the straw is pre-buried for one year to solve the problem of lack of saline-alkali paddy field crop farming technology in the prior art. The present invention returns the straw to the field, firstly, it can help the organic matter in the straw return to the soil, increase soil fertility, and at the same time avoid the problem of saprophytic microorganisms competing with crops for nutrients and water resources and unequal nutrient release rates during the straw degradation process; secondly, it can improve the soil structure, increase porosity and permeability, and block the migration of salt-alkali ions to the surface soil, which can solve the technical problems of slow growth and low yield of paddy field crops in severe saline-alkali land.

[0015] 2. Simple operation and easy to promote.

[0016] The invention has low cost, with straw cost of 300-450 yuan / mu and machinery cost of 30 yuan / mu / hectare. Moreover, the planting technology is simple and easy to learn, and can be widely promoted and applied.

[0017] 3. Good economic benefits in the later stage.

[0018] After severely saline-alkali paddy fields are improved and planted with rice, the cost can be recovered in 2 years, and the once-in-one investment can be used for a long time, with considerable economic benefits in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Comparison of rice growth conditions in saline-alkali soil before improvement and in saline-alkali soil after improvement with straw pre-burying: the three on the left are potted plants grown in the soil before improvement; the three on the right are potted plants grown in the soil after improvement. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] The straw decomposing agent of the present invention is a high-enzyme organic rapid decomposing agent purchased from Anhui Richland Biotechnology Co., Ltd.; the type of fertilizer used is a compound fertilizer (14-16-15) purchased from Shandong Lianmeng Phosphate Compound Fertilizer Co., Ltd.

[0022] Taking the improvement of saline-alkali land for planting rice paddies as an example, the present invention provides a method for improving paddy fields planted in severe saline-alkali land by pre-burying straw, and the implementation process is as follows: Step 1: Collect rice straw: In the autumn of the year before the growing season or in the spring of the current year, use a transport vehicle to collect rice straw; Step 2: Crush the rice straw: crush the rice straw to a length of 5-8 cm by a harvester; Step 3, straw covering: Use a forklift to evenly spread the crushed straw on the land, requiring the field to be dry and free of visible water to prevent the rice straw from floating with the water after covering; the laying amount of the straw is 30t / ha; Step 4: Spraying straw decomposing agent: Spray high-enzyme organic quick-decomposing agent on the surface of rice straw at a spraying rate of 35 kg / ha; Step 5: Mix the straw and soil: Use a rotary tiller to mix the crushed straw and saline-alkali soil evenly. The tillage depth is 25-30 cm; Step 6: Secondary promotion of rot: In August of the same year, use a rotary tiller again to mix the unrotten straw on the surface with the saline-alkali soil, with a rotary tillage depth of 25-30 cm; Step 7: Fertilization and irrigation: In the spring of the second year, fertilization is carried out. The fertilization plan is to apply 200 kg / ha of N during the whole growth period. The fertilizer type is compound fertilizer (14-16-15). And two irrigation and drainage to wash the salt; Step 8. Transplanting: In mid-to-late May, plant the rice seedlings in the paddy fields in an orderly manner.

[0023] Based on the above implementation process, the application examples of the present invention are as follows: Soil samples from local salinized wasteland in Changling County, Songyuan City, Jilin Province before improvement and local salinized soil samples collected and pre-buried with straw in the spring of 2023 were placed in plastic barrels. Three identical experimental replicates were set for each sample. A rice seedling cultivation experiment was carried out in the spring of 2024, and the rice seedlings were placed in a greenhouse for flooding cultivation. The results are as follows: Figure 1 shown.

[0024] Figure 1 The three potted plants on the left show the growth of rice seedlings in the soil before improvement. Figure 1 The three potted plants on the right show the growth of rice seedlings in the improved soil. It can be clearly seen from the figure that the rice seedlings in the soil before improvement grew slowly and poorly, while the rice seedlings in the soil improved by the method of the present invention grew rapidly, indicating that the method of the present invention has a significant soil improvement effect.

[0025] In summary, the present invention increases soil porosity and avoids salinity increase by returning straw to the field in the second year after the straw is plowed, without planting crops in the current year. At the same time, the straw contains a large amount of nitrogen, phosphorus, potassium and various trace nutrients. Crops are planted after the straw is fully rotted, and the nutrients in the straw can be fully and effectively utilized. On the one hand, this method helps the organic matter in the straw to fully return to the soil and increase soil fertility, while avoiding the problem of saprophytic microorganisms competing with crops for nutrients and water resources and unequal nutrient release rates during the straw degradation process; on the other hand, it can improve soil structure, increase porosity and permeability, block the migration of salt-alkali ions to the surface soil, and solve the problem of slow growth of paddy field crops in severe saline-alkali land. Combining these two aspects, a significant soil improvement effect is achieved.

Claims

1. A method for improving paddy fields in severe saline-alkali land by pre-burying straw, characterized in that: The following steps are involved: Step 1: Collect straw: Collect straw in the autumn of the year before the growing season or in the spring of the current year; Step 2: Crush the straw: crush the straw to a length of 5-8 cm by a harvester; Step 3: Straw covering: Spread the crushed straw evenly on the land, and make sure the field is dry and free of water to prevent the straw from floating with the water after covering. Step 4: Spraying the straw decomposing agent: spraying the straw decomposing agent onto the surface of the straw; Step 5: Mix straw and soil: Use a rotary tiller to mix the crushed straw and saline-alkali soil evenly, with a rotary tillage depth of 25-30 cm; Step 6: Secondary promotion of rot: In August of the same year, use a rotary tiller again to mix the unrotten straw on the surface with the saline-alkali soil, with a rotary tillage depth of 25-30 cm; Step 7: Fertilization and irrigation: In the spring of the second year, fertilize and drain and wash away the salt 2 to 3 times; Step 8. Transplanting: In mid-to-late May, plant the paddy field crop seedlings in the paddy fields in an orderly manner.

2. A method for improving paddy fields in severe saline-alkali land by pre-burying straw according to claim 1, It is characterized in that In step 1, the straw is rice straw.

3. The method for improving rice planting in severe saline-alkali land by pre-burying straw according to claim 2, characterized in that: In step three, the amount of straw laid is 30-40 t / ha.

4. The method of improving rice planting in severe saline-alkali land by pre-burying straw according to claim 3, characterized in that: In step 4, the straw decomposing agent is sprayed at a rate of 35 kg / ha.

5. The method for improving rice planting in severe saline-alkali land by pre-burying straw according to claim 4, characterized in that: The straw decomposing agent is a high-enzyme organic fast-decomposing agent.

6. The method of improving rice planting in severe saline-alkali land by pre-burying straw according to claim 5, characterized in that: In step seven, the fertilization plan is to apply 200 kg / ha of N during the entire growth period, and the type of fertilizer is compound fertilizer (14-16-15).

7. A method for improving paddy fields in severe saline-alkali land by pre-burying straw according to any one of claims 1 to 6, characterized in that: In step eight, the paddy field crop is rice.

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