Rice stubble wheat straw returning utilization method

Abstract

The invention relates to a comprehensive straw returning utilization method for wheat after rice, and aims to solve the problem of adverse effects on the growth of subsequent rice seedlings after wheat straw returning in a rice-wheat rotation area, including the problems of disease and pest propagation, uneven soil humidity, nitrogen competition and the like. The method comprises the following steps: (1) intensively carbonizing wheat straws once every 2-3 years, and firing the straws into charcoal to be stored for later use; (2) in a non-carbonization year, crushing the straws, adding a decomposition promoting microbial inoculum and urea, and carrying out composting treatment; (3) mixing the composted straws with straw carbon, and then applying the mixture into the rice field; (4) performing nutrient management according to the land capability and variety characteristics; and (5) managing water by adopting a dry-wet alternate irrigation mode. According to the comprehensive field returning utilization method for the wheat straw after rice, the soil bulk density can be reduced, the soil structure can be improved, nutrient loss can be reduced, the nutrient effectiveness can be improved, and healthy growth of rice seedlings can be promoted.

Description

Technical Field

[0001] The invention relates to agricultural technology, and in particular to the field of comprehensive field utilization of wheat straw after rice stubble. Background Art

[0002] In rice-wheat rotation areas, returning wheat straw to the field has become a common agricultural practice. With the increasing awareness of environmental protection and the need for sustainable agricultural development, returning straw to the field is considered an effective way to solve the problem of straw burning and improve soil fertility. Although returning wheat straw to the field has many advantages, there are also some problems, especially the impact on the growth of subsequent rice seedlings. The first is the spread of pests and diseases. Wheat straw may carry pathogens and pests. Returning to the field may increase the risk of pests and diseases and affect the healthy growth of rice seedlings. The second is the impact on soil moisture. Excessive straw coverage may cause uneven soil moisture and affect the root development of seedlings. The third is nitrogen competition. During the decomposition of straw, nitrogen in the soil will be consumed, resulting in a temporary lack of nitrogen in the soil, affecting the nitrogen absorption of rice seedlings, slow seedling growth, and reduced tillering. In the past, wheat straw was mainly returned to the field in full before rice transplanting, including direct plowing, mulching, and composting, but there was no research report on the comprehensive return of wheat straw to the field after rice stubble. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention aims to provide a method for comprehensive field utilization of wheat straw after rice stubble.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0005] A method for returning rice stubble and wheat straw to fields for utilization mainly comprises the following steps:

[0006] 1) Centralized carbonization of rice stubble and wheat straw

[0007] After the wheat is harvested, all the wheat straw is burned into charcoal in a carbonization furnace and stored for future use. This process is carried out every 2 to 3 years, and no wheat straw is returned to the field this year.

[0008] 2) Composting of rice stubble and wheat straw with microbial agents

[0009] Except for the years when wheat straw is carbonized in a centralized manner, in other years after wheat is harvested, the straw is collected and cut into pieces of about 5 cm using a straw crusher. Then, 6 kg of decay-accelerating bacteria and 10 kg of urea are added to every 1,000 kg of straw. The mixture is evenly spread on the straw and piled up. The piles are then covered with plastic film for insulation and allowed to compost for 15 to 20 days.

[0010] 3) Mixing composted straw and straw carbon

[0011] Before plowing the rice field, the composted straw and carbon are evenly spread in the field, and the composted straw is turned into the topsoil layer using a tiller. The amount of composted straw returned to the field is 3.0-3.6 t hm -2 (Calculated based on wheat straw yield per mu and decomposition rate of 50%), straw carbon consumption is 10.5t hm -2 .

[0012] 4) Nutrient management

[0013] The amount of fertilizer to be applied is determined according to the local soil conditions and the characteristics of the variety. Nitrogen fertilizer and urea are applied at the ratio of 4:2:2:2:basal fertilizer (1 day before transplanting): tillering fertilizer (5-7 days after transplanting): flowering fertilizer (leaf age remaining 3.5): flowering fertilizer (leaf age remaining 1.5), and phosphorus fertilizer and potassium fertilizer are applied as basal fertilizer at one time.

[0014] 5) Water management

[0015] From the time rice is transplanted to 10 days after transplanting, a 2-3 cm shallow water layer is maintained for irrigation. From 10 days after transplanting to the maturity stage, dry-wet irrigation is adopted, that is, the shallow water layer is naturally dried to the soil water potential of -(15±5) kPa, and then a 1-2 cm water layer is irrigated, and then dried, and this cycle is repeated.

[0016] Furthermore, the carbonization temperature is 500 degrees, and the main components of the charcoal fired are: carbon content 46-50%, moisture 28-30%, ash 33-37%, and volatile phenol 16-18%.

[0017] Furthermore, the decay-accelerating bacterial agent is a specific microbial agent, Bacillus subtilis, and the Bacillus subtilis can accelerate the decay and decomposition process of straw.

[0018] Furthermore, the straw crusher is an agricultural machine capable of cutting straw into pieces of about 5 cm in length.

[0019] Furthermore, the tiller is an agricultural machine capable of turning straw into the topsoil.

[0020] Furthermore, the above-mentioned method of returning rice stubble and wheat straw to the field is repeated in a cycle.

[0021] The beneficial effects of the present invention are:

[0022] The method for comprehensive returning wheat straw to the field after rice stubble provided by the present invention can, firstly, overcome the adverse effects caused by returning a large amount of wheat straw to the field, especially the problem that the rice seedlings lack nitrogen and grow slowly due to the large nitrogen consumption of straw decomposition; secondly, by periodically collecting the straw for centralized carbonization and then applying this part of carbon to the soil, it can not only reduce the soil bulk density and improve the soil structure, but also reduce the loss of nutrients in the soil due to its adsorption characteristics, improve the effectiveness of nutrients, and keep the nutrients in the soil for a longer time for absorption and utilization by the rice seedlings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the implementation process of comprehensive return of rice stubble and wheat straw to fields. DETAILED DESCRIPTION

[0024] In order to illustrate the present invention in detail, the following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that the embodiments are preferred embodiments of the present invention and are intended to illustrate the implementation conditions that can be used to implement the present invention, rather than to limit the experimental conditions.

[0025] The technical solutions in the embodiments of the present invention are described below in conjunction with the accompanying drawings.

[0026] Example 1: A method for comprehensive return of rice stubble and wheat straw to fields for utilization.

[0027] The comprehensive utilization method of rice stubble wheat straw returning to the field was tested in Jiangwang Town, Yangzhou, Jiangsu Province in 2023 and 2024. The test set up an experimental group and a control group, and each treatment was 1 mu of land, and the design was as follows:

[0028] Control group: No straw was returned to the field. All wheat straw was removed from the field before the rice field was plowed.

[0029] Experimental group 1: Straw was directly returned to the field. Before the rice field was plowed, wheat straw was directly turned into the topsoil using a tiller.

[0030] Experimental group 2: Straw charcoal. The straw charcoal was made from wheat straw. Before the rice field was plowed, the straw charcoal was evenly spread in the field at one time and turned into the topsoil layer using a tiller. The amount of straw charcoal used was 10.5 t hm -2 .

[0031] Experimental group 3: Straw carbon + bacterial agent composting. After wheat harvest, the straw was collected and cut into pieces of about 5 cm using a straw crusher. 6 kg of accelerator and 10 kg of urea were added to every 1000 kg of straw, spread evenly on the straw and piled into a pile. The pile was covered with plastic film for insulation and composting for 15 to 20 days. At the same time, the straw charcoal made from wheat straw was used. Before the rice field was plowed, the composted straw and straw carbon were evenly spread in the field, and the composted straw was turned into the topsoil layer using a tiller. The amount of composted straw returned to the field was 3.0 to 3.6 t hm -2 , the straw carbon consumption is 10.5t hm -2 .

[0032] The nutrient management and water management of each test group were consistent. The amount of fertilizer was determined according to the local soil conditions and variety characteristics. Nitrogen fertilizer and urea were applied according to the ratio of basal fertilizer (1 day before transplanting): tillering fertilizer (5-7 days after transplanting): flower-promoting fertilizer (leaf age remaining 3.5): flower-keeping fertilizer (leaf age remaining 1.5) = 4:2:2:2, and phosphorus fertilizer and potassium fertilizer were applied as basal fertilizer at one time. From the time of rice transplanting to 10 days after transplanting, a 2-3 cm shallow water layer was maintained for irrigation. From 10 days after transplanting to maturity, dry-wet irrigation was used, that is, the shallow water layer naturally dried up to the soil water potential of -(15±5) kPa, and then 1-2 cm water layer was irrigated, and then dried up, and so on.

[0033] The present invention was tested for two consecutive years in 2023 and 2024. When the rice was harvested in the two years, the number of panicles, the number of grains per panicle, the fruit setting rate, the thousand-grain weight and the yield of the experimental group and the control group were statistically analyzed. The results are shown in Table 1.

[0034] As can be seen from Table 1, in the two consecutive years of experiments, compared with the control group (no straw returning to the field), the number of ears of rice Yongyou 2640 and Nanjing 5718 in the comprehensive return of rice stubble wheat straw to the field (experimental group 3: straw carbon + microbial composting) increased by 5.3% and 5.6%, respectively, and there were no significant differences in the number of grains per ear, fruit setting rate and 1000-grain weight of the two varieties between the two treatment groups, and the actual yield increased significantly by 12.5% ​​and 9.3%, respectively; compared with experimental group 1 (direct return of straw to the field), the number of ears of rice Yongyou 2640 and Nanjing 5718 in the comprehensive return of rice stubble wheat straw to the field (experimental group 3: straw carbon + microbial composting) increased by 3.0% and 1.6%, respectively, and there were no significant differences in the number of grains per ear, fruit setting rate and 1000-grain weight of the two varieties between the two treatment groups, and the actual yield increased significantly by 7.4% and 6.3%, respectively.

[0035] Table 1 Rice yield and its components in each treatment

[0036]

[0037]

[0038] Therefore, the method for comprehensive return of wheat straw to the field after rice stubble to utilize the present invention can achieve the effects of promoting comprehensive utilization of straw, promoting tillering, improving soil fertility and increasing rice yield under the condition of not affecting the growth of rice plants, which is of great significance to the rice cultivation method under the condition of returning wheat straw to the field after rice stubble to utilize the present invention.

[0039] The above is only the optimal implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be understood and thought of by any person familiar with the technical field within the technical scope disclosed by the present invention should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for returning rice stubble and wheat straw to fields for utilization, characterized in that: The following steps are involved: 1) Centralized carbonization of wheat straw after rice stubble: After wheat is harvested, all wheat straw is burned into charcoal using a carbonization furnace and stored for future use; this process is carried out every 2 to 3 years; 2) Composting of wheat straw with microbial agents after rice stubble: Except for the years when wheat straw is carbonized in a centralized manner, in other years, after wheat is harvested, the straw is collected and cut into pieces of about 5 cm using a straw crusher. Then, 6 kg of accelerator and 10 kg of urea are added to every 1,000 kg of straw, spread evenly on the straw, and piled into piles. The piles are covered with plastic film for insulation and composting for 15 to 20 days. 3) Mixed application of composted straw and straw carbon: Before plowing the paddy field, spread the composted straw and carbon evenly in the field, and use a tiller to turn the straw into the topsoil. The amount of composted straw returned to the field is 3.0-3.6 t hm-2, and the amount of straw carbon used is 10.5 t hm-2; 4) Nutrient management: Determine the amount of fertilizer to be applied according to local soil conditions and variety characteristics. Nitrogen fertilizer and urea should be applied at the ratio of basal fertilizer: tillering fertilizer: flowering-promoting fertilizer: flower-preserving fertilizer = 4:2:2:

2. Phosphorus fertilizer and potassium fertilizer should be applied as basal fertilizer at one time. 5) Water management: From the time rice is transplanted to 10 days after transplanting, maintain a 2-3 cm shallow water layer for irrigation. From 10 days after transplanting to the maturity stage, adopt dry-wet irrigation, that is, let the shallow water layer dry naturally to the soil water potential of -(15±5) kPa, then irrigate with a 1-2 cm water layer, then let it dry, and repeat this cycle.

2. The method for returning rice stubble and wheat straw to fields for utilization according to claim 1, characterized in that: The carbonization temperature is 500 degrees, and the main components of the charcoal produced by burning include carbon, ash, etc.

3. The method for returning rice stubble and wheat straw to fields for utilization according to claim 1, characterized in that: The decay-inducing bacterial agent is a specific microbial agent Bacillus subtilis.

4. The method for returning rice stubble and wheat straw to fields for utilization according to claim 1, characterized in that: The straw shredder is an agricultural machine capable of cutting straw into pieces with a length of about 5 cm.

5. The method for returning rice stubble and wheat straw to fields for utilization according to claim 1, characterized in that: The tiller is an agricultural machine capable of turning straw into the topsoil layer.

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