Method for improving water storage and soil moisture conservation capacity of soil by returning corn straw to field in summer idle period

Abstract

The invention relates to the technical field of straw returning, in particular to a method for improving soil water storage and soil moisture conservation capacity through corn straw returning in the summer idle period, and the method comprises the steps that preceding stubble straw is removed before spring sowing; a no-tillage planter is used for seeding according to a mode of planting one plant every other root stubble, and drip irrigation and fertilization are carried out; performing zoned weeding management; 5-10 cm of stubbles are reserved during harvesting; the whole straw uniformly covers the ground surface in the summer idle period to inhibit evaporation; before sowing in autumn, straw is turned into a root zone through rotary tillage with the depth of 30 cm; furrowing and sowing are performed at the ridge spacing of 50 cm; circularly implementing the next year; according to the method, evaporation is inhibited through uniform covering of whole straw in the summer idle period, the operation cost is reduced in combination with 30 cm rotary tillage returning-to-field deep water storage in autumn and in combination with no-tillage sowing, the soil moisture preservation capacity and the crop yield are remarkably improved, and water saving, yield increasing and ecological sustainability are achieved.

Description

Technical Field

[0001] This invention relates to the field of straw return to the field technology, specifically to a method for improving soil water retention capacity by returning corn straw to the field during the summer fallow period. Background Technology

[0002] Soil moisture conditions in dryland farmland are a key factor affecting crop root distribution and growth, and determining crop yield. Returning straw organic materials to the field can improve soil water retention capacity, protect topsoil from runoff and erosion, and reduce total leaching, which is particularly beneficial for coping with climate change caused by heavy rainfall and prolonged drought in arid and semi-arid regions. However, many technologies overlook the fact that corn straw not only has a fertilizing effect but also a water-retaining effect. To address the technical problem of soil quality degradation and non-point source pollution caused by the excessive use of chemical fertilizers, pesticides, and herbicides in corn planting, Chinese patent CN111264318A discloses a planting method for corn and cover crops, the specific method of which is as follows: 1. Spring land preparation; 2. Ridging and application of base fertilizer; 3. Sowing corn; 4. Sowing cover crops on ridges; 5. Planting cover crops in furrows; 6. Corn harvesting; 7. Crushing and plowing cover crop residues the following spring; 8. Ridging the following year; 9. Field management in the second year. This method, which involves planting cover crops such as gramineous plants in furrows, can make full use of field space and prevent weed growth. Because of their high biomass, furrow-planted gramineous cover crops have a good capacity for absorbing and utilizing nitrogen from deeper soil layers, thus playing a significant role in protecting water resources and the ecological environment.

[0003] To address the problems of soil acidification and gradual decline in soil fertility, leading to reduced corn yields, Chinese patent CN115735688A discloses a cultivation method for nitrogen reduction and efficiency enhancement through intercropping corn in wide-narrow row planting with leguminous cover crops. The specific method is as follows: 1. Autumn land preparation: First, deep loosening and cultivation, followed by rotary tillage; during harrowing, ridging, and compaction, ridging should differentiate between wide and narrow rows; 2. Apply farmyard manure and organic fertilizer as basal fertilizer using machinery; biochar is applied along with the basal fertilizer; chemical fertilizers are applied according to the principle of mixed application of urea, phosphate fertilizer, and potassium fertilizer; 3. Variety selection; 4. Sowing; 5. Harvesting the grains after the corn reaches full maturity; 6. Cover crop treatment. This method can increase soil pH, improve soil fertility, and ensure increased corn yield.

[0004] While the aforementioned methods improved soil quality and increased corn yield to some extent, the harrowing, ridging, and compaction operations increased the number of times machinery entered the field, exacerbating soil compaction and hindering root growth, thus reducing nutrient absorption and lowering yield. They also increased operational costs. Furthermore, the Chinese patent with publication number CN115735688A describes the application of farmyard manure, biochar, and organic fertilizer as basal fertilizers via deep mechanical application, significantly increasing application costs. Summary of the Invention

[0005] The purpose of this invention is to provide a method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period. This method involves uniformly covering the entire stalk with corn stalks during the summer fallow period to suppress evaporation, combined with 30cm rotary tillage and returning the stalks to the field in autumn to retain deep water, and using no-till sowing to reduce operating costs. This significantly improves soil moisture retention capacity and crop yield, achieving water conservation, increased production, and ecological sustainability.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: A method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period includes the following steps: S1: Remove the straw from the previous crop: Before spring sowing, use a straw harvester to recycle the corn straw stubble, leaving no straw in the farmland; S2: Spring corn no-till planting: Corn is planted using a no-till method according to the planting pattern of "planting one plant every other root", and seedling loosening, single-plant transplanting and drip fertilization are implemented. S3: Field Management: Weeding is carried out in zones, and weeding is carried out in the corn planting area using a spraying device. Other field management is the same as that of a conventional corn field. S4: Harvesting spring corn stalks: After the corn matures, it is harvested mechanically, while the corn stubble is left in the field; S5: Returning whole corn stalks to the field during the summer fallow period: After the corn stalks are harvested, the whole stalks are evenly covered on the ground surface; S6: Rotary tillage and return of straw to the field: When preparing the land before planting corn in autumn, the straw residue from the mulch is turned into the soil through rotary tillage; S7: Crop sowing: Use a field rowing machine to open furrows and ridges, with two holes per ridge and one plant per hole, and implement drip fertilization; S8: Field management in the second year: All field management methods in the second year shall be consistent with those in the first year.

[0007] Furthermore, S2 uses a high-performance no-till planter for corn planting.

[0008] Furthermore, in S2, drip irrigation fertilization is performed using the local conventional fertilization rate of base fertilizer plus topdressing.

[0009] Furthermore, in S4, the corn stubble height is 5-10cm.

[0010] Furthermore, in S6, the depth of rotary tillage and returning of straw residue to the field is 30cm.

[0011] Furthermore, in S7, the row spacing is set to 50cm.

[0012] The beneficial effects of this invention are: This invention utilizes whole corn stalks to evenly cover the soil surface during the summer fallow period, forming a continuous physical barrier that effectively blocks the upward flow of capillary water in the soil, inhibits water evaporation, reduces surface water evaporation, and intercepts summer rainfall. Simultaneously, the three-dimensional structure of the whole stalks increases surface roughness, prolonging the retention time of rainwater runoff. The soil moisture content in the 0-20 cm layer increases by 0.42%, and in the 20-40 cm layer by 3.25%, providing a stable water supply for subsequent crops. During the rotary tillage and incorporation process before autumn sowing, the stalk residue is turned into the soil to a depth of 30 cm, allowing the decomposed organic matter to combine with the deeper soil layers, significantly improving the soil pore structure and enhancing the water-holding capacity of the 20-40 cm layer, the main distribution layer of crop roots. This closed-loop technology significantly increases soil water storage during the summer fallow period, providing a stable water supply for subsequent crops.

[0013] This invention's no-till seeding method avoids the damage to soil aggregate structure caused by traditional tillage. Combined with whole-stalk straw mulching, it reduces soil disturbance, effectively minimizing mechanical compaction and creating a loose growing environment for roots. During decomposition, straw continuously releases organic carbon, stimulating the proliferation of soil microbial communities, promoting enzyme activity, and accelerating nutrient mineralization. Deep rotary tillage buries incompletely decomposed straw in the root-active layer, further forming humus through microbial action, enhancing soil aggregate stability, and achieving dual optimization of soil physical structure and biological activity.

[0014] This invention employs no-till seeding technology, eliminating the traditional tillage and land preparation processes and directly reducing the number of times machinery needs to enter the field. Whole-stalk straw mulching eliminates the need for crushing and transportation, avoiding additional energy consumption. During the autumn land preparation stage, straw return and soil tillage are completed simultaneously in a single rotary tillage operation, replacing multiple processes such as crushing, compaction, and harrowing in the traditional method. This integrated technology significantly reduces fuel consumption and labor costs, achieving efficient resource utilization.

[0015] The dual effects of water conservation and soil improvement directly enhance crop water use efficiency, ensuring water supply during the critical growth period of maize and laying the foundation for increased yield. The 50 cm ridge spacing and the precise ridge cultivation model with two holes per ridge optimize plant spatial distribution, and combined with drip irrigation fertilization, achieve synergistic water and fertilizer supply, maximizing the yield potential of the variety. Ecologically, whole-plant mulching completely replaces straw burning, eliminating carbon emissions and particulate pollution at the source; controlled rotary tillage depth enhances the soil's ability to infiltrate and buffer against heavy rain, reducing soil erosion and meeting the needs of sustainable agricultural development in arid regions.

[0016] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period, as described in this embodiment, includes the following steps: S1: Remove the straw from the previous crop: Before spring sowing, use a straw harvester to recycle the corn straw, leaving no straw in the farmland.

[0019] S2: Spring corn no-till planting: Corn is planted using a mechanized no-till method according to the planting pattern of "planting one plant every other root", with loosening the soil around the seedlings, transplanting individual plants, and drip fertilization. S3: Field Management: Weeding is carried out in zones, and weeding is carried out in the corn planting area using a spraying device. Other field management is the same as that of a conventional corn field. S4: Harvesting spring corn stalks: Harvest the corn using mechanical methods after it matures, leaving the corn stubble in the field. S5: Whole corn stalk mulching during the summer fallow period: After the corn stalks are harvested, they are not crushed, turned over, or returned to the field. The whole stalks are evenly covered on the ground to avoid stalk accumulation or uneven distribution. S6: Rotary tillage and return of straw to the field before autumn corn planting: When preparing the land before autumn corn planting, the straw residue is turned into the soil of the original mulch crop plot through rotary tillage. S7: Crop sowing: Use a field rowing machine to open furrows and ridges, with two holes per ridge and one plant per hole, loosening the soil around the seedlings and applying fertilizer via drip irrigation. S8: Field management in the second year: All field management methods in the second year shall be consistent with those in the first year.

[0020] In this embodiment, a high-performance no-till planter is used for corn planting in S2.

[0021] In this embodiment, the corn stubble height in S4 is 5-10cm.

[0022] In this embodiment, in step S6, the straw residue is rotary tilled and returned to the field at a depth of 40cm.

[0023] In this embodiment, the row spacing in S7 is set to 50cm, and the seeding rate is plants / hm2.

[0024] Example 2 Soil moisture content (%) before sowing soil layer 0-20cm 20-40cm 40-60cm 60-80cm 80-100cm Straw not returned to the field 17.70% 16.88% 17.52% 14.20% 17.42% Whole stalk mulching 18.12% 20.13% 18.91% 17.69% 17.89% Soil moisture content (%) at corn harvest soil layer 0-20cm 20-40cm 40-60cm 60-80cm 80-100cm Straw not returned to the field 18.41% 24.50% 19.33% 18.13% 25.87% Whole stalk mulching 21.18% 24.46% 24.57% 30.89% 17.48% Soil water storage during summer fallow period (mm) soil layer 0-20cm 20-40cm 40-60cm 60-80cm 80-100cm Straw not returned to the field 53.10 50.63 60.69 42.61 52.25 Whole stalk mulching 54.36 60.39 61.71 53.07 43.38 Soil water storage during the corn season (mm) soil layer 0-20cm 20-40cm 40-60cm 60-80cm 80-100cm Straw not returned to the field 55.24 73.49 57.99 54.40 77.60 Whole stalk mulching 63.53 73.37 73.72 92.66 52.43 Soil water storage capacity at a depth of 0-100cm (mm) Summer off-season Corn season Straw not returned to the field 259.28 318.71 Straw mulching 272.91 355.72 Corn yield (kg / hm) 2 ) deal with Straw not returned to the field Whole stalk mulching Yield (kg / hm2) 17492.06 19365.08 Crop water use efficiency (kg / m²) 3 ) deal with Straw not returned to the field Whole stalk mulching WUE 1.86 1.99 As shown in the table above, in traditional corn cultivation, the exposed soil during the summer fallow period leads to severe water evaporation and insufficient deep water retention, affecting the growth of subsequent crops. This invention, however, uses whole corn stalks to evenly cover the soil surface during the summer fallow period, forming a continuous physical barrier that blocks the upward flow of capillary water in the soil, thus inhibiting water evaporation. Simultaneously, the three-dimensional structure of the stalks increases surface roughness, prolongs the retention time of rainfall runoff, and promotes water infiltration (increasing soil moisture content by 0.42% in the 0-20 cm layer and by 3.25% in the 20-40 cm layer). Creative approach: Combining autumn rotary tillage with 30 cm of soil return to the field, straw residues are turned into the main root distribution layer. After decomposition, the soil pore structure is improved, significantly enhancing the water holding capacity of the 20-40 cm soil layer and providing a stable water supply for crop roots.

[0025] Treatment of soil layers with water content of % 0-20cm 20-40cm 40-60cm 60-80cm 80-100cm Straw not returned to the field 17.70% 16.88% 20.23% 14.20% 17.42% Straw mulching 18.12% 20.13% 20.57% 17.69% 14.46% Experimental data show that using whole-stalk straw mulch during the summer fallow period to form a physical barrier on the ground effectively inhibits evaporation and intercepts rainfall, increasing the soil moisture content in the 0-20 cm topsoil layer by 0.42% (17.70%→18.12%). Combined with 30 cm deep rotary tillage to bury straw in the main root distribution layer (20-40 cm), the moisture content in this layer significantly increased by 3.25% (16.88%→20.13%), and the improved deep water storage capacity directly alleviated drought stress. The simultaneous implementation of no-till seeding and whole-stalk mulch eliminated the crushing process, reducing machinery entry into the field by 2-3 times and lowering fuel costs, demonstrating the technical advantages of "reducing operational steps and saving production costs."

[0026] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period, characterized in that, Includes the following steps: S1: Remove the straw from the previous crop: Before spring sowing, use a straw harvester to recycle the corn straw stubble, leaving no straw in the farmland; S2: Spring corn no-till planting: Corn is planted using a no-till method according to the planting pattern of "planting one plant every other root", and seedling strip loosening, single-plant transplanting and drip fertilization are implemented. S3: Field Management: Weeding is carried out in zones, and weeding is carried out in the corn planting area using a spraying device. Other field management is the same as that of a conventional corn field. S4: Harvesting spring corn stalks: After the corn matures, it is harvested mechanically, while the corn stubble is left in the field; S5: Returning whole corn stalks to the field during the summer fallow period: After the corn stalks are harvested, the whole stalks are evenly covered on the ground surface; S6: Rotary tillage and return of straw to the field: When preparing the land before planting corn in autumn, the straw residue from the mulch is turned into the soil through rotary tillage; S7: Crop sowing: Use a field rowing machine to open furrows and ridges, with two holes per ridge and one plant per hole, and implement drip fertilization; S8: Field management in the second year: All field management methods in the second year shall be consistent with those in the first year.

2. The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period as described in claim 1, characterized in that: The S2 uses a high-performance no-till planter for corn planting.

3. The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period as described in claim 1, characterized in that: In S2, drip irrigation fertilization is performed using the local conventional fertilization rate, with the base fertilizer plus topdressing applied.

4. The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period as described in claim 1, characterized in that: The corn stubble height in S4 is 5-10cm.

5. The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period as described in claim 1, characterized in that: The depth of rotary tillage and return of straw residues to the field in S6 is 30cm.

6. The method for improving soil water retention capacity by returning corn stalks to the field during the summer fallow period as described in claim 1, characterized in that: The row spacing in S7 is set to 50cm.