Cultivated land conservation method for wheat straw ridge covering and no-tillage ditch sowing of green manure

Abstract

The invention provides a cultivated land conservation method for wheat straw ridge covering and no-tillage ditch sowing of green manure, and particularly belongs to the technical field of cultivated land conservation. The cultivated land conservation method comprises the following steps that wheat is harvested, wheat straw is totally returned to the field, and stubbles of 20-25 cm are reserved; after wheat is harvested, leguminous green manure is sown in a no-tillage mode; no chemical fertilizer is applied in the green manure growth process, and irrigation is conducted in furrows in the seedling stage or the squaring stage; the green manure naturally dies and covers the earth surface, and no-tillage wheat sowing is carried out in the wheat sowing season; and repeating the steps to carry out the next round of planting. The cultivated land conservation method is remarkable in water-saving effect, has nitrogen-saving and carbon-sequestration effects, can increase the biomass of green manure and increase the yield of wheat, has small influence on the environment, and can realize cultivated land conservation.

Description

Technical Field

[0001] The present invention belongs to the technical field of cultivated land conservation, and particularly relates to a method for cultivated land conservation by ridge covering with wheat straw and no-till furrow sowing of green manure. Background Art

[0002] Dry farming areas mainly include arid, semi-arid, and semi-humid drought-prone areas, which have huge potential for reserve cultivated land resources. However, drought and low fertility are the key limiting factors for the high-quality development of agriculture in this region. The lack of water resources in dry farming areas leads to sparse vegetation in the region. In modern crop production, there is a widespread dependence on chemical nitrogen fertilizers and a lack of input of farm organic materials, resulting in a reduction in soil organic matter, a decrease in carbon and nitrogen stocks, soil compaction, and damage to soil health.

[0003] In response to the above problems, there are some existing technologies, such as straw mulching no-till technology, water-saving irrigation and furrow sowing technology, green manure and nitrogen-saving technology, and carbon sequestration and soil conservation technology.

[0004] Straw mulching no-till technology is one of the mainstream technologies in current dryland farming. By reducing the number of tillage operations and retaining the surface straw mulch, it achieves goals such as soil moisture conservation, weed suppression, and reduction of soil erosion. However, traditional mulching methods may lead to problems such as a decrease in soil temperature and may hinder sowing quality. No-till reduces soil disturbance, but straw mulching may hinder nutrient release, resulting in crop growth relying on chemical fertilizers and making it difficult to achieve the goal of nitrogen saving. In addition, the return of straw from single crops such as wheat straw is prone to competitive consumption of soil nitrogen by soil microorganisms during decomposition due to its low carbon-nitrogen ratio.

[0005] Water-saving irrigation and furrow sowing technology mainly targets the problem of water shortage. Technologies such as shallow buried drip irrigation and double-ridge furrow sowing have been gradually promoted. For example, the technology of shallow buried drip irrigation with micro-ridge furrow sowing and integrated water and fertilizer management. However, such technologies mainly focus on the irrigation and sowing links.

[0006] In the green manure and nitrogen-saving technology, the planting of green manure (such as leguminous plants) can reduce the dependence on chemical fertilizers through biological nitrogen fixation. However, the traditional turning under of green manure requires additional tillage, which conflicts with the concept of no-till and increases additional mechanical and labor inputs. The operation of traditional post-wheat multiple cropping of green manure is cumbersome, usually going through wheat straw drying, packing, removing from the farmland, rotary tillage and soil preparation, and finally sowing. Moreover, the growth season of green manure is limited, and the biomass is low, which is not enough to support the exertion of the nitrogen fixation and carbon sequestration effects of green manure. After wheat harvest, high temperature, drought, strong solar radiation, and large surface evaporation inhibit the growth of green manure. In cold and arid regions, there are problems of water resource limitation and insufficient heat, resulting in low green manure biological yields in traditional post-wheat green manure planting. After the leguminous green manure is returned to the field, there is also a problem that the decomposition rate is too fast due to the high nitrogen content in the plants, and it reaches the decomposition peak about 1 week after returning to the field. At this time, there is no main crop growing, and the proportion of green manure nutrients stored in the soil and utilized by the next-season crop is small. Existing research mostly combines green manure with crop rotation, and the green manure planting technology under no-till conditions is not yet mature.

[0007] In carbon sequestration and soil conservation technologies, straw returning to the field has been proven to promote soil carbon sequestration. However, straw mulching is difficult to balance soil nutrients because of its high internal carbon-nitrogen ratio, slow decomposition, or lack of available nitrogen in the soil due to competition for nitrogen by microorganisms. Therefore, wheat straw returning to the field needs to be combined with leguminous green manure with a higher nitrogen content to maintain soil fertility. However, there are difficulties in dealing with crop straw as solid waste in farmland, such as straw burning. Moreover, the decomposition and mineralization rate of green manure alone returning to the field is fast, which is not conducive to the expansion of the soil carbon pool and nutrient balance. There is still a problem of low water use efficiency after the combination of the two.

[0008] At present, there is a need to develop an agronomic method that can solve the problems of drought and low fertility in cultivated land, which is of great significance for the sustainable development of agriculture. Summary of the Invention

[0009] The purpose of the present invention is to provide a method for cultivating and conserving cultivated land by covering ridges with wheat straw, no-till sowing green manure in furrows. The method for cultivating and conserving cultivated land of the present invention has remarkable water-saving effect, has the functions of nitrogen-saving and carbon sequestration, can increase the biomass of green manure and the yield of wheat, has little impact on the environment, and can realize the conservation of cultivated land.

[0010] The present invention provides a method for cultivating and conserving cultivated land by covering ridges with wheat straw, no-till sowing green manure in furrows, comprising the following steps:

[0011] Harvest wheat, return the whole amount of wheat straw to the field, and leave a stubble of 20 - 25 cm;

[0012] After harvesting wheat, no-till sow leguminous green manure; the no-till sowing of leguminous green manure is to transfer the surface soil corresponding to the furrow position and the covered wheat straw to the ridge to form a micro-ridge structure; the leguminous green manure is sown on both side walls of the furrow; no chemical fertilizer is applied during the growth of green manure, and irrigation is carried out in the furrow at the seedling stage or budding stage;

[0013] Let the green manure die naturally and cover the ground surface. When it comes to the wheat sowing season, no-till sow wheat; the no-till sowing of wheat is to transfer the surface soil, wheat straw and green manure corresponding to the furrow position to the ridge to form a micro-ridge structure; the wheat is sown on both side walls of the furrow;

[0014] Repeat the above steps for the next round of planting.

[0015] Preferably, leguminous green manure is sown 0 - 3 days after harvesting wheat.

[0016] Preferably, the micro-ridge structure includes ridges and furrows. The ridge includes a ridge surface and a ridge side wall, and the furrow includes a furrow side wall and a furrow bottom surface; the height of the ridge is 10 - 15 cm, the ridge spacing between ridges is 21 - 32 cm, the width of the ridge surface is 8 - 12 cm, and the width of the furrow bottom surface is 5 - 10 cm.

[0017] Preferably, the transfer method includes transfer using a no-till seeder or manual transfer.

[0018] Preferably, the topsoil is the soil from the ground surface down to a depth of 3 cm.

[0019] Preferably, the row spacing of the leguminous green manure sown is 8 - 15 cm.

[0020] Preferably, the leguminous green manure includes vetch and / or hairy vetch; when the leguminous green manure is vetch, the seeding rate of vetch is 7 - 10 kg / mu; when the leguminous green manure is hairy vetch, the seeding rate of hairy vetch is 5 - 8 kg / mu; when the leguminous green manure is vetch and hairy vetch, the seeding rate of vetch is 6 - 9 kg / mu, and the seeding rate of hairy vetch is 1 - 3 kg / mu.

[0021] Preferably, the irrigation method includes irrigating using all the furrows or using some of the furrows.

[0022] The present invention also provides the application of the cultivated land conservation method described in the above technical solution in wheat planting.

[0023] The present invention also provides the application of the cultivated land conservation method described in the above technical solution in the functions shown in any one of ① - ⑥:

[0024] ① Increasing wheat yield;

[0025] ② Increasing wheat planting income;

[0026] ③ Increasing water use efficiency;

[0027] ④ Increasing green manure biomass;

[0028] ⑤ Increasing soil organic carbon content, total nitrogen content, nitrate nitrogen content, ammonium nitrogen content and carbon-nitrogen ratio;

[0029] ⑥ Reducing the amount of nitrogen fertilizer applied during wheat planting.

[0030] The present invention provides a method for cultivating and conserving arable land by ridge mulching with wheat straw, no-tillage and furrow sowing of green manure. The method for cultivating and conserving arable land by ridge mulching with wheat straw, no-tillage and furrow sowing of green manure in the present invention has remarkable water-saving effects: ridge mulching with wheat straw, no-tillage and furrow sowing of green manure can reduce soil disturbance, avoid damaging part of the soil crust, and significantly inhibit soil evaporation in combination with wheat straw mulching, thus inhibiting the ineffective loss of soil moisture; the micro-ridge furrow sowing of green manure forms micro-ridge furrows, and ridge and furrow irrigation (including alternative ridge and furrow irrigation) is carried out by using the micro-ridge furrows to achieve centralized irrigation for green manure crops and wheat, reduce the irrigation amount, lower the water consumption, and improve the water use efficiency; the returning of green manure and wheat straw to the field can significantly improve the physical and chemical properties of the soil and enhance the soil's water storage and moisture conservation capacity. The method for cultivating and conserving arable land in the present invention also has the dual benefits of nitrogen conservation and carbon sequestration: the planting of leguminous green manure reduces the dependence on chemical nitrogen fertilizers through biological nitrogen fixation, and provides an additional nitrogen source for the soil after returning to the field. The returning of wheat straw to the field provides a large amount of carbon source for the soil. The combination of the two balances the soil carbon and nitrogen, optimizes the nutrient balance, and is beneficial to enhancing the soil carbon sequestration function. The method for cultivating and conserving arable land in the present invention can achieve arable land conservation and sustainability: no-tillage protects the soil structure and reduces soil wind erosion; the biological coverage of green manure and wheat straw mulching inhibit weeds and reduce the use of herbicides; during the no-tillage sowing of wheat, the returning of green manure and wheat straw to the field can improve the soil fertility, form a virtuous cycle, and maintain the arable land productivity in the long term. Finally, the method for cultivating and conserving arable land in the present invention can achieve the coordination of economy and ecology: reduce mechanical tillage and chemical fertilizer input, lower the production cost; alleviate agricultural non-point source pollution, and meet the development requirements of low-carbon agriculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 Schematic diagram of ridge mulching with wheat straw and micro-ridge operation provided by the present invention;

[0033] Figure 2 Photo of ridge mulching with wheat straw, no-tillage and furrow sowing of green manure provided by the present invention;

[0034] Figure 3 Graph of green manure biomass results of ridge mulching with wheat straw, no-tillage and furrow sowing of green manure treatments (W-GS, NT) and sole green manure returning to the field (W-G, CT) provided by the present invention;

[0035] Figure 4 Graph of changes in soil organic carbon content, total nitrogen content and carbon-nitrogen ratio under different treatments provided by the present invention;

[0036] Figure 5Graph showing the changes in wheat grain yield and net income under different treatments provided by the present invention;

[0037] Figure 6 Graph showing the changes in pre-sowing soil water storage, total water consumption, and water use efficiency under different treatments provided by the present invention;

[0038] Figure 7 Graph showing the changes in wheat grain yield and net income under different treatments of wheat provided by the present invention;

[0039] Figure 8 Graph showing the changes in pre-sowing soil water storage, total water consumption, and water use efficiency under different treatments provided by the present invention;

[0040] Figure 9 Graph showing the changes in wheat grain yield and net income under different treatments provided by the present invention. Detailed implementation manners

[0041] The present invention provides a method for cultivating and conserving arable land by ridge covering with wheat straw, no-till furrow sowing of green manure, which includes the following steps:

[0042] Harvest wheat, return the whole amount of wheat straw to the field, and leave a stubble of 20 - 25 cm;

[0043] After harvesting wheat, sow leguminous green manure by no-till; the no-till sowing of leguminous green manure is to transfer the surface soil corresponding to the furrow position and the covered wheat straw to the ridge to form a micro-ridge structure; the leguminous green manure is sown on both side walls of the furrow; no chemical fertilizers are applied during the growth of the green manure, and irrigation is carried out in the furrow during the seedling stage or budding stage;

[0044] Let the green manure die naturally and cover the ground surface. When it comes to the wheat sowing season, sow wheat by no-till; the no-till sowing of wheat is to transfer the surface soil, wheat straw, and green manure corresponding to the furrow position to the ridge to form a micro-ridge structure; the wheat is sown on both side walls of the furrow;

[0045] Repeat the above steps for the next round of planting.

[0046] The arable land conservation method of the present invention can be applied to arid irrigation agricultural areas or semi-arid rain-fed agricultural areas. The technical solution of this application adopts no-till sowing in the green manure sowing stage and wheat sowing stage, and can achieve efficient conservation of arable land without additional tillage operations.

[0047] Harvest wheat, return the whole amount of wheat straw to the field, and leave a stubble of 20 - 25 cm. When harvesting wheat grains, the whole amount of wheat straw (referring to the straw of the above-ground part of wheat except for the grains) is returned to the field. The high stubble (20 - 25 cm) can provide a supporting role for the later growth of the green manure, improve the ventilation and light transmission conditions within the green manure population, and reduce the plant rot caused by the green manure lying prostrate. In a specific embodiment, the amount of wheat straw returned to the field is 600 - 750 kg / mu.

[0048] No-till seeding of leguminous green manure after wheat harvest; the no-till seeding of leguminous green manure is to transfer the surface soil corresponding to the furrow position and the covered wheat straw to the ridge to form a micro-ridge structure; the leguminous green manure is sown on the two side walls of the furrow; no chemical fertilizer is applied during the growth process of the green manure, and irrigation is carried out in the furrow during the seedling stage or budding stage. The invention of no-till seeding of leguminous green manure after wheat harvest can solve the problems that there are many operation links for sowing green manure after wheat harvest (covering wheat straw drying, bailing, removing from the farmland, rotary tillage and land preparation, and finally sowing), the growth season of the green manure is limited, and the biomass is low and insufficient to support the exertion of the carbon and nitrogen fixation effects of the green manure. In a specific embodiment, the leguminous green manure is sown 0 to 3 days after wheat harvest. In a specific embodiment, the leguminous green manure is sown immediately after wheat harvest. In a specific embodiment, the leguminous green manure includes vetch and / or hairy vetch; when the leguminous green manure is vetch, the seeding rate of vetch is 7 to 10 kg / mu; when the leguminous green manure is hairy vetch, the seeding rate of hairy vetch is 5 to 8 kg / mu; when the leguminous green manure is vetch and hairy vetch, the seeding rate of vetch is 6 to 9 kg / mu, and the seeding rate of hairy vetch is 1 to 3 kg / mu. In a specific embodiment, the transfer method includes using a no-till seeder for transfer or manual transfer. When using a no-till seeder for transfer, the transfer method includes spreading. In a specific embodiment, the no-till seeder can achieve the spreading by installing rotary knives in front of the seeder. In a specific embodiment, the surface soil is the soil from the ground surface to a depth of 3 cm. In a specific embodiment, the micro-ridge structure includes ridges and furrows, the ridge includes a ridge surface and a ridge side wall, and the furrow includes a furrow side wall and a furrow bottom; the height of the ridge is 10 to 15 cm, the ridge spacing between ridges is 21 to 32 cm, the width of the ridge surface is 8 to 12 cm, and the width of the furrow bottom is 5 to 10 cm. That is, in every 21 to 32 cm of ridge spacing, the ridge surface, the ridge side wall, the furrow side wall, the furrow bottom, the furrow side wall and the ridge side wall form a cycle, and the sum of the widths of the two side walls of the ridge and the two side walls of the furrow is 8 to 10 cm. The surface soil corresponding to the furrow position and the covered wheat straw are spread onto the ground corresponding to the ridge position, and the ridge is composed of the wheat straw at the ridge position, the soil transferred from the furrow position and the wheat straw. In a specific embodiment, the green manure row spacing for sowing the leguminous green manure is 8 to 15 cm, forming a wide-narrow row population structure in the field. The invention uses micro-ridge furrow irrigation to increase the irrigation water flow rate in the farmland and supply water to the green manure centrally. In a specific embodiment, the irrigation method includes using all the furrows for irrigation or using some of the furrows for irrigation. When using some of the furrows for irrigation, micro-ridge furrow alternate irrigation can be carried out, and the water-saving effect is good. The micro-ridge furrow alternate irrigation described in the invention means that one of the adjacent two furrows is irrigated and the other is not irrigated, and the other furrow is irrigated during the next irrigation. Specifically, when there is a drip irrigation condition, a micro-valve can be installed at the top of the drip irrigation tape for regulation, and when it is surface irrigation, a soil ridge can be built at the water inlet of every other furrow. Just wet the furrow during irrigation.In specific embodiments, irrigation is carried out 1 to 2 times depending on the soil moisture content at the seedling stage and / or the budding stage. In specific embodiments, the irrigation amount at the seedling stage can be 60 mm, and the irrigation amount at the budding stage can be 70 mm. By setting the micro-ridge structure, the wheat straw ridge covering and furrow sowing green manure of the present invention can also solve the problems of high temperature and drought after wheat harvest, strong solar radiation, and large surface evaporation, which inhibit the growth of green manure. The method of wheat straw full-amount returning to the field and no-till sowing of green manure of the present invention can reduce the operation links of growing green manure, strive for more time for the growth of green manure, thereby improving the utilization rate of light and heat resources and increasing the yield of green manure.

[0049] When the green manure naturally dies and covers the ground surface, at the wheat sowing season, wheat is sown without tillage; the no-till sowing of wheat is to transfer the surface soil, wheat straw and green manure corresponding to the ridge furrow position to the ridge to form a micro-ridge structure; the wheat is sown on both side walls of the ridge furrow; the present invention repeats the above steps for the next round of planting. No-till sowing of wheat can improve the water use efficiency of wheat. The present invention has no special limitation on the positions of the newly formed ridges and furrows relative to the original ridges and furrows during no-till sowing of wheat, and it can achieve the return of wheat straw and green manure to the field. In specific embodiments, the green manure naturally dies after the frost and covers the winter ground surface, which can reduce wind erosion and play a role in moisture conservation. In specific embodiments, wheat is sown in the coming spring. In specific embodiments, the sowing of the wheat is no-till sowing. By jointly returning wheat straw and green manure to the field, the present invention can solve the problems of the treatment of farmland carbon fixation waste such as wheat straw. The decomposition and mineralization rate of green manure alone when returned to the field is fast, which is not conducive to the amplification of the soil carbon pool and nutrient balance. Moreover, by returning double materials of leguminous green manure and wheat straw to the field, it can significantly increase soil organic matter and improve soil properties, thereby significantly improving the soil water storage and moisture conservation function from the internal function of the soil, significantly increasing the soil water storage capacity, reducing the ineffective loss of water caused by soil evaporation, and significantly increasing the soil carbon fixation and nitrogen levels. Specifically, through the microenvironment regulation of wheat straw ridge covering and no-till furrow sowing of green manure, and the reduction of evaporation and promotion of carbon accumulation by non-biological covering of wheat straw and biological covering of green manure. The present invention has no special limitation on the fertilization, irrigation and pesticide use during the wheat planting process, and conventional methods can be adopted.

[0050] The present invention forms a synergistic effect by systematically integrating wheat straw ridge covering, no-till furrow sowing, and green manure planting technologies: Wheat straw ridge covering: Optimize the covering method (such as strip covering) to solve the problem of decreasing ground temperature and conserve moisture at the same time; No-till furrow sowing: Combine the micro-ridge furrow sowing technology to achieve precise sowing and centralized irrigation, reducing water resource input; Green manure nitrogen saving: Plant leguminous green manure between the furrows, and use biological nitrogen fixation to replace part of the chemical fertilizer to make up for the nutrient loss caused by no-till; Carbon fixation and efficiency increase: Returning straw to the field and green manure to the field together can improve soil organic matter and promote carbon sequestration

[0051] The present invention also provides an application of the cultivated land conservation method described in the above technical solution in wheat planting. The cultivated land conservation method described in the present invention for wheat planting can not only achieve high yield of wheat, but also increase the biomass of green manure, save water, conserve nitrogen and fix carbon, and increase the net income.

[0052] The present invention also provides an application of the cultivated land conservation method described in the above technical solution in any one of the functions shown in ① to ⑥:

[0053] ① Increase the yield of wheat;

[0054] ② Increase the income from wheat planting;

[0055] ③ Improve the water use efficiency;

[0056] ④ Increase the biomass of green manure;

[0057] ⑤ Improve the soil organic carbon content, total nitrogen content, nitrate nitrogen content, ammonium nitrogen content and carbon-nitrogen ratio;

[0058] ⑥ Reduce the application amount of nitrogen fertilizer during wheat planting.

[0059] To further illustrate the present invention, the following is a detailed description of a cultivated land conservation method of wheat straw ridge covering, no-tillage furrow sowing and green manure in combination with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0060] Example 1

[0061] A cultivated land conservation method of wheat straw ridge covering, no-tillage furrow sowing and green manure with remarkable water-saving effect:

[0062] When harvesting wheat grains, the whole amount of wheat straw (referring to the straw of the above-ground part of wheat except for the grains) is returned to the field, and the stubble is left high at 20-25 cm, providing a support for the later growth of green manure, improving the ventilation and light transmission conditions in the green manure population, reducing the plant rot caused by the creeping of green manure, and the amount of wheat straw returned to the field is 600-750 kg / mu.

[0063] Immediately after wheat harvest, leguminous green manure is sown without tillage. When sowing, ridges are set every 30 cm, and sowing is carried out by a no-tillage seeder. A rotary knife is installed at the front end of the seeder to play a role of spreading, and the wheat straw in the furrow position and the 0-3 cm soil layer are spread to the ridge position, forming a micro-ridge structure ( Figure 1 , schematic diagram of wheat straw ridge covering and micro-ridge operation). The ridge height is 15 cm, the ridge surface width is 10 cm, and the ridge furrow width is 10 cm.

[0064] The green manure is sown on both sides of the furrow, and the row spacing of the green manure is 12 cm, forming a wide-narrow row population structure in the field; the green manure variety is selected as common vetch, and the seeding rate of common vetch is 10 kg / mu.

[0065] During the growth season of green manure, no chemical fertilizers are applied. Micro-ridge furrow irrigation is used to increase the irrigation water flow rate in the farmland and supply water to the green manure intensively. Specifically, alternate irrigation is carried out in the micro-ridges and furrows to ensure a better water-saving effect. During alternate irrigation, one furrow among two adjacent furrows is irrigated while the other is not. During the next irrigation, the other furrow is irrigated. When surface irrigation is carried out, earth dikes are built at the water inlet of every other furrow. During irrigation, it is only necessary to wet the furrows. Irrigation is carried out once at the seedling stage, with an irrigation amount of 60 mm.

[0066] After the frost, the green manure naturally dies and covers the winter ground surface, reducing wind erosion and playing a role in soil moisture conservation. When sowing wheat in the coming spring, no-till sowing is carried out. The surface soil, wheat straw, and green manure corresponding to the furrow positions are transferred to the ridges to form a micro-ridge structure. The wheat is sown on the two side walls of the furrows.

[0067] Example 2

[0068] A method for conserving arable land with significant water-saving effect, nitrogen-saving, carbon-fixing, and straw ridge-covered no-till furrow sowing of green manure:

[0069] When harvesting wheat grains, the whole amount of wheat straw (referring to the straw of the above-ground part of wheat except for the grains) is returned to the field, with a high stubble of 20 - 25 cm, and the amount of wheat straw returned to the field is 600 - 750 kg / mu.

[0070] Immediately after wheat harvest, leguminous green manure is sown without tillage. Every 24 cm during sowing, a rotary knife is installed at the front end of the seeder of the no-till seeder to play a role in spreading. The wheat straw corresponding to the furrow position and the 0 - 3 cm soil layer are spread on the ridge position to form a micro-ridge structure. The ridge height is 12 cm, the ridge surface width is 8 cm, and the furrow width is 6 cm.

[0071] The green manure is sown on both sides of the furrows, with a row spacing of 10 cm for the green manure, forming a wide-narrow row population structure in the field. The green manure variety is selected as hairy vetch, and the seeding rate of hairy vetch is 5 kg / mu.

[0072] During the growth season of green manure, no chemical fertilizers are applied. Micro-ridge furrow irrigation is used to increase the irrigation water flow rate in the farmland and supply water to the green manure intensively. Specifically, alternate irrigation is carried out in the micro-ridges and furrows. During specific operation, a micro-valve is installed at the top of the drip irrigation tape for regulation. During irrigation, it is only necessary to wet the furrows. Irrigation is carried out once at the budding stage, with a specific irrigation amount of 70 mm.

[0073] After the frost, the green manure naturally dies and covers the winter ground surface, reducing wind erosion and playing a role in soil moisture conservation. When sowing wheat in the coming spring, no-till sowing is carried out. The method is to transfer the surface soil, wheat straw, and green manure corresponding to the furrow positions to the ridges to form a micro-ridge structure. The wheat is sown on the two side walls of the furrows.

[0074] Example 3

[0075] A method for conserving arable land with significant water-saving effect, nitrogen-saving, carbon-fixing, and straw ridge-covered no-till furrow sowing of green manure:

[0076] When harvesting wheat grains, the whole amount of wheat straw (referring to the straw of the above-ground part of wheat except for the grains) is returned to the field, leaving a stubble height of 20 - 25 cm, and the amount of wheat straw returned to the field is 600 - 750 kg per mu.

[0077] Immediately after wheat harvest, leguminous green manure is sown without tillage. When sowing, every 28 cm, through a no-till seeder, a rotary knife is installed at the front of the seeder's sowing device to play a role in spreading. The wheat straw corresponding to the furrow position and the 0 - 3 cm soil layer are spread to the corresponding position of the ridge, forming a micro-ridge structure. The ridge height is 13 cm, the ridge surface width is 10 cm, and the furrow width is 8 cm.

[0078] The green manure is sown on both sides of the furrow, and the row spacing of the green manure is 12 cm, forming a wide-narrow row population structure in the field; the green manure varieties selected are common vetch and hairy vetch. The seeding rate of common vetch is 8 kg per mu, and the seeding rate of hairy vetch is 2 kg per mu.

[0079] During the growth season of the green manure, no chemical fertilizers are applied. Micro-ridge furrow irrigation is used to increase the irrigation water flow rate in the farmland and supply water to the green manure intensively; specifically, micro-ridge furrows are alternately irrigated. Specifically, when operating, a soil ridge is built at the water inlet of every other furrow for surface irrigation; when irrigating, just soak the furrow. Irrigate once at the seedling stage, with an irrigation amount of 60 mm.

[0080] After the green manure naturally dies after the frost, it covers the winter surface, reducing wind erosion and playing a role in moisture conservation; when sowing wheat in the coming spring, no-till sowing is carried out. The method is to transfer the surface soil, wheat straw, and green manure corresponding to the furrow position to the ridge, forming a micro-ridge structure; the wheat is sown on both side walls of the furrow.

[0081] Example 4

[0082] 1. Overview of the test area

[0083] The experimental base is located in Huangyang Town, Liangzhou District, Wuwei City (102°53′E, 37°44′N; altitude 1776 m), belonging to the cold temperate semi-arid climate zone, which is a typical arid irrigation agricultural area. The annual frost-free period is about 156 days, the average annual temperature is 7.3℃, the annual sunshine hours are 2945 h, the average annual rainfall is 160 mm, mainly concentrated in July - September, and the annual evaporation is as high as 2400 mm. During the crop production process, the heat resources show that there is more than enough for one season and insufficient for two seasons. Spring wheat is the main food crop in this area. After wheat harvest, most of the land is in a bare state, and the consumption of light and heat resources is serious. It is suitable to develop the wheat - green manure production model.

[0084] 2. Experimental design

[0085] A split-plot experiment design was adopted. Four treatments of organic material returning to the field were set in the main plots: wheat straw mulching on ridges with no-tillage and green manure sown in furrows (W-GS), green manure returned to the field alone (W-G), wheat straw returned to the field alone (W-S), and fallow after wheat harvest (W-F); Four nitrogen application levels were set in the sub-plots during the wheat season: local traditional nitrogen application rate (N100, 15 kg / mu), 15% reduction of local traditional nitrogen application (N85, 12.5 kg / mu), 30% reduction of local traditional nitrogen application (N70, 10 kg / mu), 45% reduction of local traditional nitrogen application (N55, 7.5 kg / mu). There were a total of 16 treatments with 3 replicates, and the treatment codes are shown in Table 1. The green manure was Vicia sativa, and experiments were conducted twice in 2022 and 2023 respectively.

[0086] Table 1 Treatment codes for different materials returned to the field and nitrogen application gradients

[0087]

[0088] The green manure was sown in late July 2021 and early August 2022 respectively. The treatment of wheat straw mulching on ridges with no-tillage and green manure sown in furrows was the same as in Example 1.

[0089] Treatment of green manure returned to the field alone: After wheat harvest, the wheat straw was baled and removed from the farmland. The green manure was sown in rows with a row spacing of 15 cm and a seeding rate of 12 kg / mu. It was shallowly rotary plowed and incorporated into the soil during the full-bloom stage of the same season (late October 2021 and 2022), and no fertilizer was applied during the green manure season.

[0090] Treatment of wheat straw returned to the field alone: The whole amount of wheat straw was returned to the field with a high stubble of 20 - 25 cm, and no green manure was planted after wheat harvest.

[0091] Wheat was sown in late March 2022 and 2023 respectively, in rows with a row spacing of 15 cm and a seeding rate of 40 kg / mu, and harvested in late July 2022 and 2023.

[0092] During the growth period of wheat, 7.5 kg / mu of P2O5 was applied as the base fertilizer; The same irrigation level was adopted, and the irrigation method was shallow buried drip irrigation. The winter storage irrigation was 80 m 3 / mu, and the multiple cropping of Vicia sativa after wheat was irrigated 33 m 3 / mu and 40 m 3 / mu respectively during the branching stage and the early budding stage, and spring wheat was irrigated 50 m 3 / mu, 60 m 3 / mu, 50 m 3 / mu during the seedling stage, booting stage, and filling stage respectively. Other field management was the same as that of local high-yield fields.

[0093] 3. Test indicators

[0094] Indicators such as water storage before sowing, total water consumption, water use efficiency, soil organic carbon, carbon-nitrogen ratio, and wheat yield.

[0095] 4. Test Results

[0096] The treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges can significantly increase the biomass of green manure compared with the treatment of returning green manure to the field alone. Sowing green manure in furrows with no-tillage and wheat straw mulched on ridges ( Figure 2 , photo of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges) can effectively solve the problem of difficult sowing of green manure after wheat straw is returned to the field, significantly reduce the operation links such as wheat straw treatment before sowing green manure and land preparation, and can achieve the purpose of sowing green manure in a timely manner, preserving soil moisture and increasing the biomass of green manure. Research shows that compared with the treatment of returning green manure to the field alone, the treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges can reduce the mechanical power consumption of green manure sowing by more than 46%, increase the emergence rate of green manure in the field by 9.7%, and increase the biomass of green manure by 23.6% ( Figure 3 , result chart of green manure biomass of the treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges (W-GS, NT) and the treatment of returning green manure to the field alone (W-G, CT)).

[0097] As can be seen from Table 2, compared with fallow after wheat harvest, whether returning green manure or wheat straw to the field can effectively increase the soil water storage before sowing and after harvest, reduce the total water consumption during the growth period, and thus improve the water use efficiency. Compared with the traditional nitrogen application amount after fallow after wheat harvest, the soil water storage before sowing of the treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges, the treatment of returning green manure to the field alone, and the treatment of returning wheat straw to the field alone under the traditional nitrogen application amount increased by 19.9%, 14.6% and 11.6% respectively, the water storage after harvest increased by 58.0%, 42.1% and 35.4% respectively, the total water consumption during the growth period decreased by 11.9%, 8.5% and 7.6% respectively, and the water use efficiency increased by 22.6%, 16.5% and 13.1% respectively. Among them, the treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges has a greater effect on improving the water use efficiency of wheat than the treatment of returning green manure and wheat straw to the field alone, and this effect is more significant under 30% reduction of nitrogen application. Compared with fallow after wheat harvest, the water storage before sowing increased by 15.7%, the water storage after harvest increased by 36.3%, the total water consumption decreased by 14.1%, and the water use efficiency increased by 16.5%.

[0098] Table 2 Changes in soil water storage before sowing, water storage after harvest, total water consumption and water use efficiency under different treatments

[0099]

[0100]

[0101] Under the traditional nitrogen application amount, compared with fallow after wheat harvest, the soil organic carbon content of the treatment of sowing green manure in furrows with no-tillage and wheat straw mulched on ridges, the treatment of returning green manure to the field alone, and the treatment of returning wheat straw to the field alone increased by 10.8%, 6.2% and 6.3% respectively ( Figure 4 A in Figure 4 ), the soil carbon-nitrogen ratio increased by 8.4%, 2.6% and 4.0% respectively ( Figure 5in A), and the net income of the treatment of wheat straw ridge mulching, no-tillage furrow sowing and green manure increased by 7.2% ( Figure 5 in B). Under the condition of reducing nitrogen application by 30%, the soil organic carbon content, carbon-nitrogen ratio, wheat grain yield and net income of the treatment of wheat straw ridge mulching, no-tillage furrow sowing and green manure reached the maximum values, which were increased by 7.3%, 7.9%, 4.9% and 5.8% respectively compared with the traditional nitrogen application after wheat harvest and fallow. Therefore, the treatment of wheat straw ridge mulching, no-tillage furrow sowing and green manure can achieve stable wheat yield under the condition of reducing nitrogen application by 30%. It is a cultivated land conservation method to break through the water resource and heat constraints of multiple cropping green manure in the northwest irrigation area, effectively increase the organic input of farmland, promote soil fertility improvement and carbon sequestration while reducing chemical nitrogen fertilizer, maintain the continuous stable and high yield of wheat, and promote the improvement of production capacity. Figure 4 Figure shows the changes in soil organic carbon content, total nitrogen content and carbon-nitrogen ratio under different treatments, Figure 5 Figure shows the changes in wheat grain yield and net income under different treatments.

[0102] Example 5

[0103] 1. General situation of the test area

[0104] A demonstration experiment was conducted in Songshu Town, Liangzhou District, Wuwei City (102°54′E, 37°94′N). This area belongs to the temperate continental arid climate and is a typical arid irrigation agricultural area. The average annual rainfall is 160 mm, the annual sunshine hours are 2968 h, the average annual temperature is 7.9 °C, the annual frost-free period is about 160 d, and the annual evaporation is as high as 2010 mm. It is a typical irrigation agricultural area with more than one season and less than two seasons. Wheat is widely planted in this area. After wheat harvest, the farmland is bare and the straw resources are idle, resulting in serious resource depletion. Therefore, it is appropriate to promote the wheat-green manure production model.

[0105] 2. Experimental design

[0106] A field experiment was carried out in 2023. The randomized block experimental design was adopted, with three treatments: wheat straw ridge mulching, no-tillage furrow sowing and green manure + traditional nitrogen application (CVS+N100), wheat straw ridge mulching, no-tillage furrow sowing and green manure + nitrogen reduction by 30% (CVS+N70), and traditional nitrogen application after wheat harvest and fallow as the control (CK). The treatment codes are shown in Table 3.

[0107] Table 3 Different treatment codes

[0108]

[0109]

[0110] The field management methods of the corresponding treatments are the same as those in Example 1.

[0111] 3. Test indexes

[0112] Indicators such as soil organic carbon, water storage before sowing, water consumption, water use efficiency, wheat yield, and net income.

[0113] 4. Test Results

[0114] The results showed that: as can be seen from Table 4, the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows significantly increased the contents of soil organic carbon, total nitrogen, carbon-nitrogen ratio, nitrate and ammonium nitrogen, and decreased the soil bulk density. Compared with the traditional nitrogen application in the fallow period after wheat harvest, the contents of soil organic carbon, total nitrogen, carbon-nitrogen ratio, nitrate and ammonium nitrogen in the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows under traditional nitrogen application and 30% nitrogen fertilizer reduction increased by 14.3%, 20.0%, 40.3%, 15.4%, 20.0% and 7.8%, 14.3%, 34.8%, 12.8%, 19.7% respectively.

[0115] Figure 6 Figure showing the changes in soil water storage before sowing, total water consumption and water use efficiency under different treatments, Figure 7 Figure showing the changes in wheat grain yield and net income under different treatments. Compared with the traditional nitrogen application amount in the fallow period after wheat harvest, the soil water storage before sowing in the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows under traditional nitrogen application and 30% nitrogen fertilizer reduction increased by 10.8% and 8.7% ( Figure 6 A in Figure 6 ), the total water consumption decreased by 6.9% and 9.5% ( Figure 6 B in Figure 7 ), the water use efficiency increased by 29.7% and 30.3% ( Figure 7 C in

[0116] Table 4 Changes in soil organic carbon, total nitrogen, carbon-nitrogen ratio, nitrate nitrogen, ammonium nitrogen contents and soil bulk density under different treatments

[0117]

[0118] Example 6

[0119] 1. Overview of the Test Area

[0120] A field demonstration experiment was conducted in Liuba Town, Yongchang County, Jinchang City. This area is located in the eastern part of the Hexi Corridor in Gansu Province (102°7′E, 38°12′N), with a temperate continental climate. It is a typical arid irrigation agricultural area, with an altitude of 1873 m, an average annual temperature of 6.3 °C, an average annual rainfall of 179 mm, an average frost-free period of 140 days, an average annual sunshine duration of 2945 h, and an annual evaporation of more than 2000 mm. Wheat is the main crop planted in this area. After wheat harvest, the farmland is bare and the straw resources are idle, making it suitable to promote the wheat-green manure model.

[0121] 2. Experimental design

[0122] A randomized block experimental design was adopted, with treatments including straw ridge mulching no-tillage furrow sowing green manure treatment + traditional nitrogen application (CVS + N100), straw ridge mulching no-tillage furrow sowing green manure treatment + 30% nitrogen fertilizer reduction (CVS + N70), and traditional nitrogen application amount after wheat harvest as the control (CK). There were a total of 3 treatments, and the treatment codes are shown in Table 5. One experiment was conducted in 2023.

[0123] Table 5 Different treatment codes

[0124] Treatment Code Treatment of Straw Ridge Mulching No-tillage Furrow Sowing Green Manure + Traditional Nitrogen Application CVS + N100 Treatment of Straw Ridge Mulching No-tillage Furrow Sowing Green Manure + 30% Reduction of Traditional Nitrogen Application CVS + N70 Post-wheat Fallow CK

[0125] The field management measures for each treatment refer to Example 1.

[0126] 3. Test indicators

[0127] Indicators such as soil organic carbon, water storage before sowing, water consumption, water use efficiency, wheat yield, and net income.

[0128] 4. Experimental results

[0129] The results showed that: as can be seen from Table 6, the straw ridge mulching no-tillage furrow sowing green manure treatment significantly increased the contents of soil organic carbon, total nitrogen, carbon-nitrogen ratio, nitrate-ammonium nitrogen, and decreased soil bulk density. Compared with traditional nitrogen application after wheat harvest, the contents of soil organic carbon, total nitrogen, carbon-nitrogen ratio, nitrate, and ammonium nitrogen in the straw ridge mulching no-tillage furrow sowing green manure treatment increased by 13.5%, 18.4%, 37.3%, 16.5%, 19.2% and 7.3%, 13.2%, 32.2%, 13.7%, 18.9% respectively under the traditional nitrogen application rate and 30% nitrogen fertilizer reduction.

[0130] Figure 8 It is a graph showing the changes in soil water storage before sowing, total water consumption, and water use efficiency under different treatments. Figure 9 It is a graph showing the changes in wheat grain yield and net income under different treatments. Compared with the traditional nitrogen application amount after wheat harvest, the soil water storage before sowing in the straw ridge mulching no-tillage furrow sowing green manure treatment increased by 18.6% and 16.4% ( Figure 8 A inFigure 8 In B) of Figure 8 in C), the grain yield increased by 19.9% and 16.9% Figure 9 in A), the net income increased by 38.2% and 33.3% Figure 9 in B). Therefore, the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows combined with a 30% reduction in traditional nitrogen application is a cultivated land conservation method for realizing the efficient utilization of regional water resources, substituting partial chemical nitrogen fertilizer, increasing the soil carbon pool, promoting stable and high yields of crops, and increasing farmers' income.

[0131] Table 6 Changes in soil organic carbon, total nitrogen, C / N ratio, nitrate nitrogen and ammonium nitrogen contents under different treatments

[0132]

[0133] Comparative Example 1:

[0134] This comparative example compared the advantages and disadvantages of the solution of the present invention with no-tillage mulching (background literature: No-tillage mulching: an effective measure for sustainable agriculture) and the traditional drilling method of vetch mixed with hairy vetch (background literature: Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat).

[0135] 1. Overview of the test area

[0136] The test base is located in Huangyang Town, Liangzhou District, Wuwei City (102°53′E, 37°44′N; altitude 1776 m), belonging to the cold temperate semi-arid climate zone. The annual frost-free period is about 156 days, the average annual temperature is 7.3 °C, the annual sunshine hours are 2945 h, the average annual rainfall is 160 mm, mainly concentrated in July-September, and the annual evaporation is as high as 2400 mm. During the crop production process, the heat resources show that there is more than enough for one season and insufficient for two seasons. Spring wheat is the main food crop in this area. After wheat harvest, most of the land is left bare, and the consumption of light and heat resources is serious. It is suitable to develop the wheat-green manure production mode.

[0137] 2. Test design

[0138] A split-plot experiment design was adopted. In the main plots, three treatments of returning organic materials to the field were set: ridge mulching with wheat straw, no-till furrow sowing of green manure (Vicia sativa), no-till straw mulching (the optimal treatment in the literature: no-till mulching: an effective measure for sustainable agriculture), traditional strip sowing of Vicia sativa mixed with Vicia villosa (the optimal treatment in the literature: Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat); in the sub-plots, four nitrogen application levels were set in the wheat season: local conventional nitrogen application rate (N100, 15 kg / mu), 15% reduction in nitrogen fertilizer (N85, 12.5 kg / mu), 30% reduction in nitrogen fertilizer (N70, 10 kg / mu), no nitrogen application. There were a total of 12 treatments with 3 replicates.

[0139] The treatment of ridge mulching with wheat straw, no-till furrow sowing of green manure is the same as in Example 1.

[0140] No-till straw mulching (background literature: no-till mulching: an effective measure for sustainable agriculture) means covering the straw of main crops such as wheat and corn on the surface of the field for returning to the field. The characteristics of these crop straws are that they have a relatively high carbon content and are difficult to decompose after returning to the field. During the decomposition process, they will cause a large amount of soil alkaline hydrolyzable nitrogen to be consumed by soil microorganisms, resulting in a decrease in soil alkaline hydrolyzable nitrogen, thus leading to the phenomenon of nitrogen competition between soil microorganisms and main crops.

[0141] In the scheme of the present invention, leguminous crops can symbiotically fix nitrogen with rhizobia, fixing atmospheric nitrogen into the farmland. Leguminous crop plants have a relatively high nitrogen content. After returning to the field, they play a role in carbon-nitrogen balance with wheat straw with a high carbon content, avoiding the phenomenon of nitrogen competition between soil microorganisms and crops.

[0142] Traditional strip sowing of Vicia sativa mixed with Vicia villosa (background literature: Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat) means that after wheat harvest, the wheat straw is baled and removed from the farmland, and then rotary tillage and stubble cleaning are carried out before sowing green manure.

[0143] The scheme of the present invention omits the links of baling and removing wheat straw from the farmland and rotary tillage and stubble cleaning, and increases the wheat straw returning material with a high carbon content compared with the background literature.

[0144] 3. Experimental results

[0145] (1) The amount of organic materials returned to the field in different ways

[0146] The total amount of organic materials returned to the field is the highest in the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows. Especially under the condition of reducing nitrogen application by 30%, the total amount of returned materials is 970.8 kg / mu, and there is no significant difference from the treatment of local conventional nitrogen application rate. The total amount of returned materials in the treatment of no-tillage with straw mulching ranks second, but it mainly depends on wheat straw and the contribution of green manure is zero. The total amount of returned materials in the treatment of vetch intercropped with hairy vetch sown in rows is the lowest, especially under the condition of nitrogen reduction or no nitrogen application. Ridge mulching with wheat straw, no-tillage and green manure sowing in furrows performs the best in terms of the amount of organic materials returned to the field. It can utilize both green manure and wheat straw under nitrogen application conditions to form a relatively high total amount of returned materials. Although the amount of returned materials in the treatment of no-tillage with straw mulching is relatively high, it only depends on wheat straw and lacks the nitrogen fixation effect of green manure, which may cause excessive consumption of soil nitrogen during the decomposition of wheat straw with high decomposition carbon content in long-term soil improvement. The amount of returned materials in the treatment of vetch intercropped with hairy vetch sown in rows is relatively low, especially under the condition of nitrogen reduction or no nitrogen application, which limits its improvement of soil fertility. The results of the amount of organic materials returned to the field are shown in Table 7 for details.

[0147] Table 7 The amount of organic materials returned to the field

[0148]

[0149] The amount of carbon and nitrogen returned to the field is the highest in the treatment of ridge mulching with wheat straw, no-tillage and green manure sowing in furrows. Especially under the condition of reducing nitrogen application by 30%, the amount of carbon returned to the field is 490.2 kg / mu, and the amount of nitrogen returned to the field is 18.6 kg / mu, with no significant difference from the treatment of local conventional nitrogen application rate. The amount of carbon and nitrogen returned to the field in the treatment of no-tillage with straw mulching ranks second, but the nitrogen source is single (only from wheat straw), and the carbon-nitrogen ratio is relatively high (93.3 - 112.8), which may affect the short-term availability of nitrogen. The amount of carbon and nitrogen returned to the field in the treatment of vetch intercropped with hairy vetch sown in rows is the lowest, especially under the condition of nitrogen reduction or no nitrogen application. Ridge mulching with wheat straw, no-tillage and green manure sowing in furrows performs the best in terms of the amount of carbon and nitrogen returned to the field and the carbon-nitrogen ratio. The carbon-nitrogen ratio is 26.3 (under the condition of reducing nitrogen application by 30%), within the ideal range of the carbon-nitrogen ratio of organic materials (20 - 30), which is beneficial to soil microbial activities and nitrogen release. The carbon-nitrogen ratio of no-tillage with straw mulching is relatively high (93.3 - 112.8), which may lead to competition for nitrogen between microorganisms and plants and affect the short-term fertilizer efficiency. The carbon-nitrogen ratio of vetch intercropped with hairy vetch sown in rows is moderate (14.4 - 16.5), but due to the relatively low amount of returned materials and the excessive decomposition of soil organic matter by microorganisms caused by the relatively low carbon-nitrogen ratio, it may limit its improvement of soil fertility. The results of the amount of carbon and nitrogen returned to the field under different returns of organic materials are shown in Table 8 for details.

[0150] Table 8 The amount of carbon and nitrogen returned to the field under different returns of organic materials

[0151]

[0152] (2) The water use efficiency of wheat under different methods

[0153] As shown in Table 9, the wheat water use efficiency of wheat with ridge mulching, no-tillage, and green manure sowing in furrows is the highest (1.61 kg / mu·mm, with 30% nitrogen reduction), showing no significant difference from the treatment with local customary nitrogen application rate, and significantly higher than other treatments. The water use efficiencies of no-tillage straw mulching and the intercropping of vetch with the sowing of hairy vetch in rows are similar, but slightly lower than that of wheat with ridge mulching, no-tillage, and green manure sowing in furrows. Under the condition of no nitrogen application, the water use efficiencies of all treatments decreased significantly, especially for no-tillage straw mulching (0.70 kg / mu·mm). The wheat with ridge mulching, no-tillage, and green manure sowing in furrows performs optimally in terms of water use efficiency, which may be related to its covering layer reducing evaporation and improving the soil water retention capacity. The water use efficiencies of no-tillage straw mulching and the intercropping of vetch with the sowing of hairy vetch in rows are similar, but slightly lower than that of wheat with ridge mulching, no-tillage, and green manure sowing in furrows. Under the condition of no nitrogen application, the water use efficiencies of all treatments decreased significantly, indicating that nitrogen fertilizer plays an important role in improving water use efficiency.

[0154] Table 9 Wheat Yield and Water Use Efficiency under Different Organic Matter Return to Field

[0155]

[0156] (3) Nitrogen Use Efficiency of Wheat under Different Methods

[0157] As shown in Table 10, the nitrogen fertilizer utilization rate and nitrogen recovery rate of wheat with ridge mulching, no-tillage, and green manure sowing in furrows are the highest. Under the condition of 30% nitrogen reduction, the nitrogen fertilizer utilization rate is 26.8 kg / kg, and the nitrogen recovery rate is 54.8%. The nitrogen fertilizer utilization rate and recovery rate of no-tillage straw mulching and the intercropping of vetch with the sowing of hairy vetch in rows are the second, but the improvement amplitude is small. Under the condition of no nitrogen application, the nitrogen uptake of all treatments is relatively low (7.0 - 6.8 kg / mu). The wheat with ridge mulching, no-tillage, and green manure sowing in furrows performs optimally in terms of nitrogen use efficiency. Especially under the condition of nitrogen reduction, the nitrogen fertilizer utilization rate and recovery rate increase significantly, indicating that its nitrogen fixation by green manure reduces the dependence on chemical fertilizers. The nitrogen use efficiency of no-tillage straw mulching and the intercropping of vetch with the sowing of hairy vetch in rows is the second, but the improvement amplitude is limited, which may be related to its relatively weak nitrogen fixation ability of green manure. Under the condition of no nitrogen application, the nitrogen uptake of all treatments is relatively low, indicating that appropriate nitrogen application is crucial for wheat growth and nitrogen uptake.

[0158] Table 10 Nitrogen Use Efficiency of Wheat under Different Organic Matter Return to Field

[0159]

[0160]

[0161] In summary, the wheat straw ridge mulching no-tillage and green manure sowing in furrows treatment showed the best performance in terms of the amount of organic matter returned to the field, the amount of carbon and nitrogen returned to the field, water use efficiency, and nitrogen use efficiency. Especially under the condition of nitrogen reduction, it could still maintain high yields and fertilizer efficiency. Through the synergistic effect of nitrogen fixation by green manure and wheat straw mulching, this treatment significantly improved soil fertility and resource use efficiency. No-tillage straw mulching and the mixed sowing of vetch and hairy vetch in drills performed well in some indicators, but the overall effect was not as good as that of wheat straw ridge mulching no-tillage and green manure sowing in furrows. Especially the carbon-nitrogen ratio of no-tillage straw mulching was relatively high, which might limit its short-term fertilizer efficiency. Under the condition of no nitrogen application, the effects of all treatments decreased significantly, indicating that nitrogen fertilizer plays an irreplaceable role in wheat growth and resource use efficiency.

[0162] The advantages of the wheat straw ridge mulching no-tillage and green manure sowing in furrows mode compared with no-tillage straw mulching and the mixed sowing of vetch and hairy vetch in drills are as follows:

[0163] The wheat straw ridge mulching no-tillage and green manure sowing in furrows mode showed the best performance in terms of the amount of organic matter returned to the field, the amount of carbon and nitrogen returned to the field, water use efficiency, and nitrogen use efficiency, and is suitable for popularization and application under similar ecological conditions.

[0164] Under the wheat straw ridge mulching no-tillage and green manure sowing in furrows mode, appropriate nitrogen reduction (such as a 30% reduction) can still maintain high yields and fertilizer efficiency, which helps to reduce chemical fertilizer input and environmental pressure.

[0165] Avoid single straw mulching or green manure planting: The effects of no-tillage straw mulching and the mixed sowing of vetch and hairy vetch in drills are limited. It is recommended to combine the synergistic effects of green manure and straw to improve soil fertility and resource use efficiency.

[0166] Comparative Example 2:

[0167] This comparative example compared the advantages and disadvantages of the solution of the present invention with the coordinated return of green manure and wheat straw in no-tillage sowing of green manure (background literature: Response of water use characteristics of spring wheat in arid irrigation areas to the coordinated return of green manure and wheat straw) and the traditional drilling of the mixed sowing of vetch and hairy vetch (background literature: Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat).

[0168] 1. Overview of the test area

[0169] The comparative experiments were conducted respectively in Huangyang Town, Liangzhou District, Wuwei City (102°53′E, 37°44′N; altitude 1776 m, belonging to the cold temperate semi-arid climate zone, and being a typical arid irrigation agricultural area), and Anding District, Dingxi City (104°12′E, 35°17′N, being a typical semi-arid rain-fed agricultural area).

[0170] The annual frost-free period in Huangyang Town, Liangzhou District, Wuwei City is about 156 days, the average annual temperature is 7.3 °C, the annual sunshine hours are 2945 h, the average annual rainfall is 160 mm, mainly concentrated in July - September, and the annual evaporation is as high as 2400 mm. In the process of crop production, the heat resources show that there is surplus for one season but insufficiency for two seasons. Spring wheat is the main food crop in this area. After wheat harvest, most of the land is in the bare state, and the consumption of light and heat resources is serious. Therefore, it is appropriate to develop the wheat - green manure production mode.

[0171] The average altitude of Anding District, Dingxi City is 1898.7 m. The average annual temperature is 6.3 °C, the average annual precipitation is about 400 mm, and the frost-free period is 141 days. The distribution of precipitation within a year is extremely uneven, mainly concentrated in summer and autumn (July - September). The solar radiation is strong and the heat resources are rich, which is very suitable for the growth of spring-sown crops. Due to the lack of river runoff, except for a few river valleys with irrigation conditions, the growth and development of crops in most areas rely on rain-fed. This area belongs to a typical semi-arid rain-fed agricultural area.

[0172] 2. Experimental design

[0173] The split-plot experimental design was adopted. Three organic material returning treatments were set in the main plots: ridge mulching with wheat straw and no-till furrow sowing of green manure (Vicia sativa), no-till sowing of green manure and coordinated returning of wheat straw (background literature: Response of water use characteristics of spring wheat in arid irrigation areas to the coordinated returning of green manure and wheat straw), traditional drilling of Vicia sativa mixed with Vicia villosa (optimal treatment in the literature: Legume greenmanure can intensify the function ofchemical nitrogen fertilizer substitutionviaincreasingnitrogen supply anduptake ofwheat). There were 3 treatments in total, with 3 replicates.

[0174] No-till sowing of green manure and coordinated straw return to the field (background literature: Response of water use characteristics of spring wheat in arid irrigation areas to the coordinated return of green manure and wheat straw to the field). After covering the wheat straw on the surface of the field for returning to the field, a no-till seeder is used for flat sowing without forming a micro-ridge structure. In the irrigation agricultural area, when surface irrigation is carried out, the water flow is not concentrated, the irrigation speed is slow, the irrigation efficiency is low, and the irrigation is prone to unevenness; in the rain-fed agricultural area, the effect of rainwater collection cannot be achieved. In the solution of the present invention, a micro-ridge structure is formed. In the irrigation area, the ridge ditch can be used to form a concentrated water flow during surface irrigation, and the irrigation water is concentrated on the root system of the green manure crop, thereby improving the irrigation efficiency; in the rain-fed agricultural area, the rainwater can be concentrated in the ridge ditch to achieve the effect of gathering rainwater and improving the water use efficiency.

[0175] Traditional strip sowing of Vicia sativa mixed with Vicia villosa (background literature: Legume green manure can intensify the function of chemical nitrogen fertilizer substitution via increasing nitrogen supply and uptake of wheat). After wheat harvest, the wheat straw is baled and removed from the farmland, and then rotary tillage and stubble cleaning are carried out before sowing green manure. The solution of the present invention omits the links of baling and removing wheat straw from the farmland and rotary tillage and stubble cleaning, and increases the wheat straw returning material with a high carbon content compared with the traditional strip sowing of Vicia sativa mixed with Vicia villosa. In addition, the solution of the present invention has the advantage of improving water use efficiency compared with the traditional method of strip sowing Vicia sativa mixed with Vicia villosa.

[0176] 3. Test results

[0177] (1) Green manure biomass and wheat yield performance

[0178] As shown in Table 11, in the irrigation agricultural area, the green manure biomass of the "ridge-covered no-till ditch sowing of green manure with wheat straw" treatment (364.5 kg / mu) is significantly higher than that of "no-till sowing of green manure and coordinated straw return to the field" (341.8 kg / mu) and "traditional strip sowing of Vicia sativa mixed with Vicia villosa" (325.7 kg / mu). At the same time, the wheat straw return amount (634.2 kg / mu) and the total return material amount (998.7 kg / mu) are the highest, which are increased by 16.8% and 12.9% respectively compared with "no-till sowing of green manure and coordinated straw return to the field", and the advantage is more significant compared with "traditional strip sowing of Vicia sativa mixed with Vicia villosa" (no wheat straw return). In terms of wheat yield, the treatment of the present invention (556.4 kg / mu) is increased by 2.7% and 3.6% respectively compared with "no-till sowing of green manure and coordinated straw return to the field" (541.6 kg / mu) and "traditional strip sowing of Vicia sativa mixed with Vicia villosa" (537.3 kg / mu).

[0179] The rain-fed agricultural area shows the same trend: the green manure biomass (316.3 kg / mu), wheat straw returning amount (426.2 kg / mu), and wheat yield (389.2 kg / mu) under the treatment of the present invention are all better than those of the other two methods. Compared with "no-till sowing of green manure and coordinated returning of wheat straw", the green manure biomass increases by 10.1%, and the wheat yield increases by 7.4%; compared with "traditional drilling of vetch and hairy vetch in mixed cropping", the wheat yield increase reaches 18.7%.

[0180] Table 11 Performance of green manure biomass, total amount of returned materials, and wheat yield under different treatments

[0181]

[0182] (2) Soil water storage and water use efficiency

[0183] As shown in Table 12, in the irrigated agricultural area, the pre-sowing soil water storage of green manure (367.2 mm) and the pre-sowing water storage of wheat (386.7 mm) under the treatment of "ridge covering with wheat straw and no-till furrow sowing of green manure" are both higher than those of other treatments, indicating that the micro-ridge structure effectively improves the soil water retention capacity. At the same time, the water consumption of green manure (132.4 mm) and the water consumption of wheat (342.4 mm) are the lowest, which are reduced by 9.8% and 4.5% respectively compared with "no-till sowing of green manure and coordinated returning of wheat straw", and reduced by 19.3% and 6.9% compared with "traditional drilling of vetch and hairy vetch in mixed cropping", indicating that the present invention significantly reduces the consumption of ineffective water.

[0184] In the rain-fed agricultural area, the pre-sowing water storage of green manure (350.2 mm) and the pre-sowing water storage of wheat (362.4 mm) under the treatment of the present invention also lead, and the water consumption of green manure (128.9 mm) and the water consumption of wheat (256.4 mm) are lower than those of other methods, further verifying the rainwater harvesting and soil moisture conservation effect of the micro-ridge structure.

[0185] Table 12 Performance of green manure biomass, total amount of returned materials, and wheat yield under different treatments (mm)

[0186]

[0187] As shown in Table 13, in the irrigated agricultural area, the water use efficiency of green manure (2.75 kg / mu·mm) and wheat (1.62 kg / mu·mm) in "green manure with wheat straw ridge covering, no-till furrow sowing" are significantly higher than those in "no-till sowing of green manure and synergistic straw return to field" (2.33, 1.51) and "traditional strip sowing of vetch and hairy vetch mixed cropping" (1.98, 1.46), with increases of 18.0% and 7.3% respectively. In the rain-fed agricultural area, the water use efficiency of green manure and wheat in the present invention (2.45, 1.52) is increased by 16.7% and 16.0% compared with that in "no-till sowing of green manure and synergistic straw return to field" (2.10, 1.31), and increased by 35.4% and 38.2% compared with that in "traditional strip sowing of vetch and hairy vetch mixed cropping" (1.81, 1.10), indicating that the present invention has more prominent advantages in water-limited environments.

[0188] Table 13 Water use efficiency of green manure and wheat under different treatments (kg / mu·mm)

[0189]

[0190] The "green manure with wheat straw ridge covering, no-till furrow sowing" of the present invention optimizes the irrigation and rainwater collection efficiency through the micro-ridge structure, and at the same time eliminates the wheat straw baling and rotary tillage stubble removal links of traditional strip sowing, achieving a higher wheat straw return amount (634.2 kg / mu) and the total amount of returned materials (998.7 kg / mu). Compared with the comparative methods, the present invention shows significant advantages in terms of green manure biomass, wheat yield, soil water retention capacity and water use efficiency. Especially in arid and semi-arid regions, it can reduce water consumption by 10% - 20% and increase water use efficiency by 16% - 38%. The solution of the present invention provides innovative technical support for improving resource utilization efficiency and promoting sustainable agriculture.

[0191] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all of them. People can also obtain other embodiments based on these embodiments without creative efforts, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A method for cultivating and conserving arable land by ridge covering with wheat straw and no-tillage ditch sowing green manure, comprising the following steps: Harvest wheat, return the whole amount of wheat straw to the field, and leave a stubble of 20 - 25 cm; Sow leguminous green manure without tillage after harvesting wheat; the no-tillage sowing of leguminous green manure is to transfer the surface soil corresponding to the ridge ditch position and the covered wheat straw to the ridge to form a micro-ridge structure; the leguminous green manure is sown on both side walls of the ridge ditch; no chemical fertilizer is applied during the growth of the green manure, and irrigation is carried out in the ridge ditch at the seedling stage or budding stage; Let the green manure die naturally and cover the ground surface. When it comes to the wheat sowing season, sow wheat without tillage; the no-tillage sowing of wheat is to transfer the surface soil, wheat straw and green manure corresponding to the ridge ditch position to the ridge to form a micro-ridge structure; the wheat is sown on both side walls of the ridge ditch; Repeat the above steps for the next round of planting.

2. The cultivated land conservation method according to claim 1, wherein Sow leguminous green manure within 0 - 3 days after harvesting wheat.

3. The cultivated land conservation method according to claim 1, characterized in that, The micro-ridge structure includes ridges and ridge ditches. The ridge includes a ridge surface and a ridge side wall, and the ridge ditch includes a ridge ditch side wall and a ridge ditch bottom surface; the height of the ridge is 10 - 15 cm, the ridge spacing between ridges is 21 - 32 cm, the width of the ridge surface is 8 - 12 cm, and the width of the ridge ditch bottom surface is 5 - 10 cm.

4. The cultivated land conservation method according to claim 1, characterized in that, The transfer method includes using a no-tillage seeder for transfer or manual transfer.

5. The cultivated land conservation method according to claim 1, characterized in that, The surface soil is the soil from the ground surface to a depth of 3 cm.

6. The cultivated land conservation method according to claim 1, characterized in that, The row spacing of the sown leguminous green manure is 8 - 15 cm.

7. The cultivated land conservation method according to claim 1, characterized in that, The leguminous green manure includes vetch and / or hairy vetch; when the leguminous green manure is vetch, the seeding rate of vetch is 7 - 10 kg / mu; when the leguminous green manure is hairy vetch, the seeding rate of hairy vetch is 5 - 8 kg / mu; when the leguminous green manure is vetch and hairy vetch, the seeding rate of vetch is 6 - 9 kg / mu, and the seeding rate of hairy vetch is 1 - 3 kg / mu.

8. The cultivated land conservation method according to claim 1, characterized in that The irrigation method includes irrigating using all the ridge ditches or using some of the ridge ditches for irrigation.

9. Application of the arable land conservation method according to any one of claims 1 - 8 in wheat planting.

10. Application of the arable land conservation method according to any one of claims 1 - 8 in the functions shown in any one of ① - ⑥: ① Improve wheat yield; ② Increase the income from wheat planting; ③ Improve water use efficiency; ④ Increase the biomass of green manure; ⑤ Increase the soil organic carbon content, total nitrogen content, nitrate nitrogen content, ammonium nitrogen content and carbon-nitrogen ratio; ⑥ Reduce the amount of nitrogen fertilizer applied during wheat planting.

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