Detailed Explanation of Soybean Cultivation Technology with Film Mulching Between Rows on Wide Ridges

Heilongjiang Province is China's main soybean production area, with its planting area accounting for 7% of the national total and its current total output accounting for 11% of the national total. In the course of soybean production development, the Heilongjiang Reclamation Area has vigorously promoted scientific and technological innovation, resulting in a relatively large increase in soybean yield per unit area and total output. From 2001 to 2005, the average yield per hectare reached 2531.7 kg; in 2005, the average soybean yield per mu reached 178 kg, reaching or approaching the soybean yields of advanced countries worldwide.

The soybean cultivation technology with film mulching between rows on wide ridges refers to a planting method and its corresponding cultivation techniques in which the row spacing is 130 cm on wide ridges, 60 cm film is used for mulching on the ridges, and the seedling bands on both sides of the film are planted within 5 cm of the film. This technology is a high-yield cultivation model formed on the basis of summarizing and absorbing soybean inter-row film mulching, the soybean three-ridge cultivation technology, and the soybean "deep, narrow, dense" cultivation technology, and in response to the ecological characteristic of uneven precipitation during the soybean growth period. The average soybean yield per mu under film mulching between rows on wide ridges reaches 225 kg, an increase of more than 30% over soybeans without film mulching.

1. Theoretical Basis

For high-yield cultivation technology, "good seed and good method" is only an effective way to transform soybeans from low yield to medium yield. To move from medium yield to high yield or even higher yield, the three factors of variety, technology, and ecology must be considered. Obtaining high soybean yield requires conditions in 3 aspects: first, the variety. Without a variety with great yield-increasing potential, no matter how superior the technology or environment, high yield cannot be obtained. Second, ecological or environmental conditions. If the environmental conditions are good and can meet the external requirements of high-quality and high-yield soybeans, then high yield and high quality can be obtained; if the environmental conditions are poor, they cannot be obtained. Among ecological conditions, those that affect soybean yield and quality are mainly water, temperature, fertilizer, and light. Third, cultivation technology and cultivation measures. Cultivation technology actually includes cultivation models and cultivation measures. A cultivation technology and cultivation model should have their own characteristics. In essence, under a certain ecological condition, they change and improve a certain ecological factor in the ecological conditions that does not conform to the growth ecology required for high-quality and high-yield soybeans, ultimately achieving the goal of high yield and high quality.

2. Main Technical Measures

1. Land preparation: carry out land preparation in summer and autumn, and strictly prohibit wet land preparation. For plots without a subsoiling foundation, adopt subsoiling with a depth of more than 35 cm; for plots with a subsoiling foundation, adopt harrowing of stubble or rotary tillage, with stubble harrowing density of 15-18 cm and rotary tillage depth of 14-16 cm. In autumn, form 130 cm wide ridges, with a ridge surface width of 80 cm, and compact them.

2. Variety selection: select approved and promoted varieties with high quality, high yield, strong stress resistance, and the ability to mature normally locally.

3. Plastic film selection: select plastic film with a thickness of 0.01 mm and a width of 60 cm.

4. Sowing period: sowing can begin when the soil temperature at 5-10 cm stably passes 5°C. In eastern Heilongjiang, sowing can be done from April 25 to May 1, and in northern areas from April 28 to May 5.

5. Planting density: follow the principle that fertile land should be sparse and lean land should be dense, with 220,000-260,000 seedlings retained per hectare.

6. Sowing method: select the 2BM-3 general-purpose film-mulching tillage and seeding machine or the 2BM-1 inter-row film-mulching general-purpose tillage and seeding machine, and use single seedling-band air-suction precision hill sowing outside the film on the ridge, with the seedling band 2-3 cm from the film and not exceeding 5 cm. Complete fertilization, film mulching, sowing, compaction, and other operations in one pass.

7. Film mulching standard: the film should be laid straight, with a deviation of no more than 5 cm per 100 m, and both sides should be pressed with soil at 10 cm each. In eastern areas, press soil horizontally on the film every 10-20 m; in western areas, press soil horizontally on the film every 1.3-1.4 m to prevent strong winds from lifting the film.

8. Sowing standard: accurate sowing rate, with a positive or negative error not exceeding 1%, and sow to the end and to the edge.

9. Fertilization: apply 120-150 kg of pure N, P, and K per hectare. For black soil, the N:P:K ratio is 1:1.5:0.6, and for albic soil it is 1:1.2:0.6. Adopt layered side-deep fertilization. Fertilizer is placed 10 cm from the seed side inside the film; 1/3 of the fertilizer is applied 5-7 cm below the film on the seed side, and 2/3 of the fertilizer is applied 7-12 cm below the film on the seed side.

At the early flowering stage, seed-filling stage, and early pod-setting stage of soybean, carry out foliar topdressing separately. The reference formula is to apply 4.5 kg of urea and 2.25 kg of potassium dihydrogen phosphate per hectare. The first application can be done by machine or by aerial application; the second and third applications are mainly by aerial application. Accurate measurement, sufficient spray volume, and no missed or repeated application are required.

10. Chemical weed control: the weed control method is mainly pre-sowing soil treatment, supplemented by stem and leaf treatment. For pre-sowing soil treatment and stem and leaf treatment, the pesticide variety and application rate should be selected according to the weed species and the soil conditions at the time. Stem and leaf treatment can use a sprayer for seedling-band application. The spray volume is 150-200 L per hectare for soil treatment and 150 L per hectare for stem and leaf treatment. For soil treatment, herbicides such as Jinduer, isopropachlor, and Henais (90% acetochlor) can be selected. For post-emergence treatment, herbicides such as quizalofop-p-ethyl, sethoxydim, and quizalofop-p-ethyl can be selected.

11. Cultivation management: carry out cultivation 3 times during the soybean growth period. Carry out the 1st cultivation at the soybean emergence stage, with a depth of 15-18 cm, or subsoil the furrow to 18-20 cm, so that the furrow and ridge sides have a relatively thick active soil layer; carry out the 2nd cultivation when soybeans have 2 compound leaves, with a depth of 8-12 cm; carry out the 3rd cultivation before ridge closing, with a depth of 8-12 cm.

12. Chemical regulation: when soybean growth is too vigorous, select chemical regulators such as paclobutrazol and triiodobenzoic acid at the early flowering stage for regulation to prevent lodging later.

13. Residual film recovery: remove all film before soybean ridge closing and recover it to prevent pollution. After lifting the film, carry out cultivation between the mulched rows.

3. Matters Needing Attention

Do not choose varieties that are too late-maturing; choose varieties that can mature normally locally. The planting density should be controlled at about 250,000 plants per hectare. The soybean inter-row film mulching technology should be selected for application in arid areas or arid years, and it is not easy to apply this technology on plots with sufficient moisture. Choose film with high tensile strength to facilitate film recovery and avoid environmental pollution.