Planting method for high-efficiency utilization of nitrogen in maize-medic intercropping
The intercropping method of maize and alfalfa has solved the problem of low nitrogen fertilizer utilization in monoculture of maize, achieved efficient nitrogen utilization and increased maize yield, and solved the problem of reduced output value of gramineous crops per unit area.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF ANIMAL SCI & VETERINARY HUBEI ACADEMY OF AGRI SCI
- Filing Date
- 2026-05-11
- Publication Date
- 2026-07-14
AI Technical Summary
The low nitrogen fertilizer utilization rate in the existing maize monoculture planting model leads to diminishing returns and environmental degradation in the farmland system. At the same time, intercropping of the two grain crops reduces the yield of gramineous crops per unit area, which cannot meet the yield requirements of the target crop.
The intercropping method of corn and alfalfa was adopted, with a row ratio of 1:1 between corn and alfalfa. Nitrogen utilization was rationally controlled, and fertilizer input was reduced and nitrogen utilization efficiency was improved through root complementarity, nitrogen fixation and nutrient complementarity.
It significantly improves maize grain yield and nitrogen fertilizer utilization, alleviates nitrogen stress in agricultural areas, reduces nitrogen loss from the system, achieves high-efficiency and stable yield, and improves land use efficiency.
Abstract
Description
Technical Field
[0001] This invention relates to the field of intercropping technology, specifically to a method for efficient nitrogen utilization in corn-alfalfa intercropping. Background Technology
[0002] Nitrogen is a crucial biological factor for crop growth, development, and organogenesis, generally distributed in the most active parts of plants (new leaves, meristems, reproductive organs, etc.). Nitrogen supply directly affects crop growth and development, contributing 40%–50% to final yield. It is an important component of plant proteins, nucleic acids, phospholipids, and certain growth hormones. It is also a major component of enzymes, coenzymes, and prosthetic groups such as NAD+, NADP+, and FAD+, as well as certain plant hormones and vitamins that regulate life activities. The amount of available nitrogen absorbed by plants from the soil is an important indicator of their growth status and a key environmental factor for improving plant growth and development in soil-poor areas.
[0003] Corn is an important food crop in my country, as well as a crucial feed and industrial raw material. In recent years, due to the continuous optimization of the grain consumption structure and the increase in feed and processing consumption, the supply and demand situation for corn in my country has become tighter, and the supply-demand gap has widened. Traditional corn is grown using intensive monoculture methods, which generally result in excessive application of nitrogen fertilizer. However, the nitrogen fertilizer utilization rate for corn in the current season is only 31.0% to 42.6%, leading to diminishing returns on farmland systems and environmental degradation, threatening agricultural sustainability.
[0004] Chinese patent CN116686652A discloses a method for efficient nitrogen utilization in intercropping of corn and soybeans, belonging to the field of intercropping technology. This cultivation technique uses corn and soybeans intercropped at a row ratio of 2:2. This technique utilizes the differences in nitrogen utilization among different crops' biological characteristics to rationally control the planting ratio of corn and soybeans, fully leveraging the nitrogen-fixing characteristics of legumes, reducing fertilizer input, and improving production efficiency. However, the two grain crops easily compete for nitrogen absorption in the soil, and the substitution of one crop for another in intercropping leads to a decrease in the yield of a single crop per unit area, failing to adequately meet the demand for target crop yields.
[0005] Therefore, those skilled in the art are dedicated to providing an intercropping method that can provide a clean nitrogen source for farmland, reduce nitrogen fertilizer input while maintaining crop yield, improve nitrogen use efficiency, reduce emissions, stabilize production and increase efficiency, and has considerable potential. Summary of the Invention
[0006] This invention provides a planting method for efficient nitrogen utilization in intercropping of maize and alfalfa, which solves the problem mentioned in the background art that the two grain crops easily compete for nitrogen absorption in the soil, and that intercropping with legumes and grasses leads to a decrease in the yield of grasses per unit area and a reduction in nitrogen content, which cannot well meet people's demand for the yield of the target crops.
[0007] To achieve the above-mentioned technical objectives, the present invention mainly adopts the following technical solutions: This invention discloses a planting method for high-efficiency nitrogen utilization in maize-alfalfa intercropping, comprising: intercropping maize and alfalfa with a row ratio of 1:1 between maize and alfalfa; a plant spacing of 15-25 cm between maize plants; row sowing of alfalfa; and a row spacing of 20-40 cm between maize and alfalfa.
[0008] In a preferred embodiment of the present invention, the seeding rate of alfalfa is 10-15 kg ha. -1 .
[0009] In a preferred embodiment of the present invention, the following steps are specifically included: S1 Soil preparation before sowing: In February of the first year, the land to be planted should be plowed. Before sowing, the previous crop or weeds should be removed. The plowing depth should be 15-20 cm, and the land should be plowed 2-3 times and then leveled. S2 fertilization: Apply phosphorus and potassium fertilizer once before planting crops, then apply nitrogen fertilizer before sowing alfalfa and corn, and apply nitrogen fertilizer when corn reaches the large trumpet stage; S3 Intercropping: Sow alfalfa in mid-March; sow corn in mid-April when the alfalfa has grown to the branching stage; S4 Field Management: Field management of the planting area during the growing season; S5 Planting and Harvesting: Alfalfa was harvested in June of the same year, and corn was harvested from the end of July to the beginning of August.
[0010] Preferably, the corn variety selected is the Denghai No. 9 variety, which is tolerant to high density, disease-resistant, and high-yielding; the alfalfa selected is the American Radino variety, which is leafy, palatable, high-yielding, and resistant to disease and stress.
[0011] In a preferred embodiment of the present invention, in step S1, the soil preparation before sowing requires the harvesting of the previous crop to be completed by the end of October of the previous year, the planting land to be leveled in November, and then left fallow until sowing in the following year.
[0012] In a preferred embodiment of the present invention, in step S2, the phosphate fertilizer is applied at a rate of 120 kg P2O5 ha. -1 The potassium fertilizer is applied at a concentration of 100 kg K2O ha -1Apply 36 kg N ha of nitrogen fertilizer before sowing alfalfa. -1 Apply 80 kgN ha of nitrogen fertilizer before corn planting. -1 Apply 80 kg N ha of nitrogen fertilizer during the large trumpet stage. -1 .
[0013] In a preferred embodiment of the present invention, the nitrogen fertilizer is urea with pure nitrogen ≥ 46%, the phosphate fertilizer is superphosphate with P2O5 ≥ 12%, and the potassium fertilizer is potassium sulfate.
[0014] In a preferred embodiment of the present invention, in step S3, the alfalfa sowing depth during intercropping is set to 1-1.5 cm, and the seeds are kept close to the soil during sowing to ensure that the alfalfa seeds fall evenly; the corn sowing depth is set to 4-8 cm, and the corn sowing depth is kept consistent to ensure uniform emergence.
[0015] In a preferred embodiment of the present invention, step S4, field management specifically includes the following steps: (1) Field weeding: After the alfalfa seedlings emerge in the early stage of planting, strip weeding is carried out to ensure that the sowing strips are free of weeds before planting corn. (2) Conduct a comprehensive inspection of alfalfa emergence and re-sow within one month of emergence to ensure uniform alfalfa emergence. (3) Conduct a comprehensive inspection of the corn seedling emergence status, replant missing seedlings, thin out multiple seedlings, and maintain one healthy seedling at each location to ensure full seedling emergence in the area.
[0016] In a preferred embodiment of the present invention, step S5 specifically includes the following steps: (1) Harvest alfalfa by cutting along the planting strips, leaving a stubble of 5-8 cm; (2) Harvest corn: Cut all the corn along the roots and remove it from the planting area, then dry and thresh it.
[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a planting method for efficient nitrogen utilization in maize-alfalfa intercropping. By taking advantage of the differences in biological characteristics and nitrogen utilization among different crops in the grass-legume intercropping system, reasonable regulation can fully utilize the advantages of biological nitrogen fixation, thereby reducing fertilizer input, improving production efficiency, and making the planting system more stable, high-yielding, and efficient. This method can promote nitrogen fixation in legumes, increase crop grain yield and nitrogen productivity, and achieve efficient nitrogen utilization in grass crops. The rational intercropping of maize and alfalfa in this invention can promote the nitrogen absorption and utilization capacity of maize through root complementarity, nitrogen fixation, nutrient complementarity and nitrogen transfer, effectively alleviate nitrogen stress in agricultural areas, reduce systemic nitrogen loss, improve land use efficiency, significantly increase maize grain yield and nitrogen fertilizer utilization rate, and achieve synergistic optimization of the biological nitrogen fixation of leguminous crops and the nitrogen competition effect of gramineous crops. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0019] Example 1 The implementation area of this invention is located in Jiangxia District, Wuhan City, Hubei Province, which belongs to the subtropical plain area, with an altitude of 29.6 m, an average annual temperature of 16.7 ℃, an extreme maximum temperature of 40.1 ℃, an extreme minimum temperature of -14.1 ℃, an annual rainfall of 1277 mm, and a frost-free period of 260-296 days. The soil is hilly yellow soil.
[0020] Experimental varieties: The maize variety selected was Denghai No. 9, which is tolerant to high density, disease-resistant, and high-yielding; the alfalfa variety selected was the American Radino variety, which is leafy, palatable, high-yielding, and resistant to disease and stress.
[0021] The implementation method is as follows: S1 Soil Sowing Preparation: The previous crop is harvested by the end of October of the previous year. The planting land is leveled in November and then left fallow until the following year for sowing. The planting land is then plowed in February of the first year. Before sowing, the previous crop or weeds are removed. The plowing depth is 15-20 cm, and the land is plowed 2-3 times and then leveled. S2 Fertilization: First apply 120 kg of P2O5 ha -1 and 100 kg K2O ha -1 Apply phosphate and potassium fertilizers separately in one application; then apply 36 kg N ha of nitrogen fertilizer before sowing alfalfa. -1 Apply 80 kg N ha of nitrogen fertilizer before corn planting. -1 Then, when the corn reaches the large trumpet stage, apply 80 kg N ha of nitrogen fertilizer as a top dressing. -1 The nitrogen fertilizer is urea (pure nitrogen ≥ 46%), the phosphate fertilizer is superphosphate (P2O5 ≥ 12%), and the potassium fertilizer is potassium sulfate.
[0022] Specifically, before sowing, mix the phosphate and potassium fertilizers and spread them evenly on the surface of the sowing area. Apply urea evenly to the sowing strips according to the prescribed amount. Apply nitrogen fertilizer during the mid-term of corn growth. At the large trumpet stage, apply urea evenly to the corn sowing strips according to the prescribed amount.
[0023] S3 Intercropping: Alfalfa is sown in mid-March; corn is sown in mid-April when the alfalfa reaches the branching stage. Corn and alfalfa are intercropped, with a row ratio of 1:1; the plant spacing between corn plants is 20 cm; alfalfa is sown in rows at a rate of 11.25 kg / ha. -1 The row spacing between corn and alfalfa is 30 cm. When intercropping, the sowing depth of alfalfa is set at 1-1.5 cm, and the seeds should be kept close to the soil during sowing to ensure uniform seeding. The sowing depth of corn is set at 4-8 cm, and the corn should be sown at a consistent depth to ensure uniform emergence.
[0024] S4 field management involves routine field management of the planting area during the growing season; specifically, it includes the following steps: (1) Field weeding: After the alfalfa seedlings emerge in the early stage of planting, strip weeding is carried out to ensure that the sowing strips are free of weeds before planting corn. (2) Conduct a comprehensive inspection of alfalfa emergence and re-sow within one month of emergence to ensure uniform alfalfa emergence. (3) Conduct a comprehensive inspection of the corn seedling emergence status, replant missing seedlings, thin out multiple seedlings, and maintain one healthy seedling at each location to ensure full seedling emergence in the area.
[0025] S5 is planted and harvested, with alfalfa harvested in June of the same year, and corn harvested from late July to early August. The specific steps include: (1) Harvest alfalfa by cutting along the planting strips, leaving a stubble of 5-8 cm; (2) Harvest corn: Cut all the corn along the roots and remove it from the planting area, then dry and thresh it.
[0026] Comparative Example 1 To compare the advantages and disadvantages of the nitrogen-efficient intercropping method of maize-alfalfa of the present invention, a maize field was planted using the traditional maize monoculture method as a comparison. The specific method is as follows: (1) Soil sowing is prepared as described in S1 above; (2) Apply fertilizer before sowing. Apply phosphorus and potassium fertilizers as described in S2 above. Apply nitrogen fertilizer at 80 kg N ha before sowing corn. -1 Apply 80 kg N ha of nitrogen fertilizer when the plant reaches the large trumpet stage. -1Nitrogen fertilizer is urea (pure nitrogen ≥ 46%), phosphorus fertilizer is superphosphate (P2O5 ≥ 12%), and potassium fertilizer is potassium sulfate; (3) The selection of corn varieties is the same as in Example 1; (4) The corn sowing time is the same as that described in S3 above, the plant spacing between corn plants is 20 cm, and the row spacing between corn plants is 60 cm; (5) Field management for monoculture corn fields is the same as described in S4 above; (6) The corn harvesting method is the same as described in S5 above; The yield and nitrogen content of maize planted using the planting method of Example 1 of the present invention and the conventional method provided in Comparative Example 1 were investigated, and the results are shown in Table 1.
[0027] intercropping of maize and alfalfa 24.01±1.37 228.12±21.70 12.64±0.63 137.93±11.04 Maize monoculture 23.44±1.28 199.39±11.59 11.90±0.64 132.29±6.88 Alfalfa monoculture 2.57±0.41 83.82±12.33 As shown in Table 1, the total yield and grain yield of maize in the maize-alfalfa intercropping field provided by the method of the present invention are higher than those in the maize monoculture field. At the same time, by measuring the total nitrogen concentration, the total nitrogen content and grain nitrogen content of maize in the intercropping field are calculated to be higher than those in the maize monoculture field.
[0028] In summary, this invention, through reasonable intercropping of maize and leguminous forage grasses, can promote the nitrogen absorption and utilization capacity of maize through root complementarity, nitrogen fixation, nutrient complementarity, and nitrogen transfer, effectively alleviating nitrogen stress in agricultural areas, thereby reducing systemic nitrogen loss, improving land use efficiency, and significantly increasing maize grain yield and nitrogen fertilizer utilization rate. Its core mechanism lies in the synergistic optimization of the biological nitrogen fixation of leguminous plants and the nitrogen competition effect of gramineous crops.
[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for efficient nitrogen utilization in intercropping of maize and alfalfa, characterized in that, include: Corn and alfalfa were intercropped, with a row ratio of 1:1 between corn and alfalfa. The plant spacing between corn plants is 15-25 cm; alfalfa is sown in rows; the row spacing between corn and alfalfa is 20-40 cm.
2. The planting method according to claim 1, characterized in that, The seeding rate of alfalfa is 10-15 kg / ha. -1 .
3. The planting method according to claim 1, characterized in that, Specifically, the steps include the following: S1 Soil preparation before sowing: In February of the first year, the land to be planted should be plowed. Before sowing, the previous crop or weeds should be removed. The plowing depth should be 15-20 cm, and the land should be plowed 2-3 times and then leveled. S2 fertilization: Apply phosphorus and potassium fertilizer once before planting crops, then apply nitrogen fertilizer before sowing alfalfa and corn, and apply nitrogen fertilizer when corn reaches the large trumpet stage; S3 Intercropping: Sow alfalfa in mid-March; sow corn in mid-April when the alfalfa has grown to the branching stage; S4 Field Management: Field management of the planting area during the growing season; S5 Planting and Harvesting: Alfalfa was harvested in June of the same year, and corn was harvested from the end of July to the beginning of August.
4. The planting method according to claim 3, characterized in that, The corn variety selected is the Denghai No. 9, which is tolerant to high density, disease-resistant, and high-yielding; the alfalfa variety selected is the American Radino variety, which is leafy, palatable, high-yielding, and resistant to disease and stress.
5. The planting method according to claim 3, characterized in that, In step S1, the soil preparation before sowing requires the harvesting of the previous crop by the end of October of the previous year, the leveling of the planting land in November, and then fallow until the sowing of the following year.
6. The planting method according to claim 3, characterized in that, In step S2, the phosphate fertilizer is applied at a rate of 120 kg P2O5 ha. -1 The potassium fertilizer is applied at a concentration of 100 kg K2O ha -1 Apply 36 kg N ha of nitrogen fertilizer before sowing alfalfa. -1 Apply 80 kg N ha of nitrogen fertilizer before corn planting. -1 Apply 80 kg N ha of nitrogen fertilizer during the large trumpet stage. -1 .
7. The planting method according to claim 3, characterized in that, The nitrogen fertilizer is urea with pure nitrogen ≥ 46%, the phosphate fertilizer is superphosphate with P2O5 ≥ 12%, and the potassium fertilizer is potassium sulfate.
8. The planting method according to claim 3, characterized in that, In step S3, the alfalfa sowing depth is set to 1-1.5 cm during intercropping. During sowing, ensure that the seeds are close to the soil and that the alfalfa seeds fall evenly. The corn sowing depth is set to 4-8 cm. Keep the corn sowing depth consistent to ensure uniform emergence.
9. The planting method according to claim 3, characterized in that, Step S4, field management specifically includes the following steps: (1) Field weeding: After the alfalfa seedlings emerge in the early stage of planting, strip weeding is carried out to ensure that the sowing strips are free of weeds before planting corn. (2) Conduct a comprehensive inspection of alfalfa emergence and re-sow within one month of emergence to ensure uniform alfalfa emergence. (3) Conduct a comprehensive inspection of the corn seedling emergence status, replant missing seedlings, thin out multiple seedlings, and maintain one healthy seedling at each location to ensure full seedling emergence in the area.
10. The planting method according to claim 3, characterized in that, Step S5 specifically includes the following steps: (1) Harvest alfalfa by cutting along the planting strips, leaving a stubble of 5-8 cm; (2) Harvest corn: Cut all the corn along the roots and remove it from the planting area, then dry and thresh it.