Detailed Explanation of Key Points of High-Yield and High-Efficiency Soybean Cultivation Techniques

China is the place of origin of soybean, and soybean has always been one of China's main food and oil crops. For a long period after the founding of New China, China's soybean area, output and export volume remained first in the world. However, since the 1990s, China has developed slowly in the breeding of high-yield and high-quality soybean varieties and in the research, testing, assembly and promotion of supporting high-yield and high-efficiency cultivation techniques, and the yield per unit area could not be raised, resulting in low comparative benefits of soybean planting. At the same time, the United States, Brazil, Argentina and other countries have developed soybean rapidly, and their share in the international soybean market has become larger and larger, dealing a great impact on the development of China's soybean production. At present, China's annual soybean output is about 13 million t, accounting for only 10% of the world's total and ranking fourth in the world. In 1996, China changed from a soybean exporting country to a net importing country. By 2000, the import volume of soybean and soybean cake exceeded more than 9 million t, making China the world's largest importing country. Entering the 21st century, with the continuous improvement of people's quality of life, the demand for soybean will become greater and greater. For this reason, while paying attention to breeding new soybean varieties, technical extension work must be done well. On the one hand, research, testing and demonstration of new supporting techniques should be strengthened; on the other hand, the assembly, promotion and application of existing high-yield cultivation techniques should be carried out well, and efforts should be made to raise the soybean yield per unit area.
During the "Tenth Five-Year Plan" period, the main spring soybean production areas in Northeast China should continue to promote relatively mature techniques such as the "ridge three" cultivation, Yongchang model cultivation and Xingfu model cultivation, and strengthen the research, demonstration and promotion of narrow-row dense planting technology and its derived technologies such as large-ridge dense planting, small-ridge dense planting and flat-planting narrow-row dense planting. With the goals of increasing yield, improving quality and saving costs, and with fine sowing, scientific fertilization and integrated control as the technical priorities, soybean should be rotated with corn and wheat to solve the problems of continuous cropping and alternating cropping. At the same time, suitable high-yield supporting techniques and field management measures should be studied, assembled and promoted in different ecological regions, and the standardization, intensification and mechanization of soybean production should be vigorously promoted, so that by the end of the "Tenth Five-Year Plan" period the average soybean yield per unit area will reach about 2700 kg/hectare. This will make Northeast China the main production area for China's commercial soybean and export soybean. In the Huang-Huai-Hai summer soybean production area and the multiple-cropping soybean production areas in the South, according to different ecological and climatic conditions and the growth and development characteristics of different varieties, suitable supporting high-yield cultivation techniques should be promoted and applied, with good work done in timely early sowing, rational dense planting, plastic film mulching cultivation, application of plant growth regulators, field disease and pest control, and rational intercropping, relay intercropping and rotation with wheat, corn, vegetables and other crops, and demonstration and promotion of vegetable soybean technology should be carried out, striving to make the soybean yield per unit area in the Huang-Huai-Hai and southern production areas reach 2250 kg/hectare after 5 years, basically meeting local demand. During the "Tenth Five-Year Plan" period, emphasis should be placed on promoting the "ridge three" cultivation and narrow-row dense planting techniques.
II. Operating Procedures
(I) Variety Selection and Treatment
Select high-quality soybean varieties with large yield-increasing potential and good internal and external quality, such as Hefeng 35, Suinong 14, Heinong 33, Yudou 22, Ludou 11, Zhonghuang No. 4, etc., requiring a seed germination rate above 90% and purity above 98%. Carry out careful seed selection before sowing, removing diseased seeds and impurities, etc. At the same time, according to different soil environments and disease and pest conditions, select suitable seed coating agents for coating; in some cases, micro-fertilizers, bacterial fertilizers, ABT rooting powder, etc. can also be used for seed dressing to enhance seed vigor.
(II) Rational Tillage, Land Preparation and Rotation
Soybean planting should adhere to rational rotation. In Northeast China, it can be rotated with corn, wheat, etc.; in the Huang-Huai-Hai and southern production areas, it can be rotated with wheat, vegetables, etc., to reduce the area of continuous cropping and alternating cropping, and at the same time return straw to the field as much as possible to improve soil fertility. Land preparation should follow the principle of deep loosening. The main soybean production areas in Northeast China use deep-loosening rotary tillers for deep loosening and stubble harrowing to enhance soil permeability and drought resistance and waterlogging tolerance, with a general plowing depth of about 20 cm. For ridge-cultivated soybean, land preparation should be combined with ridging, so that both the ridge body and the furrow are deeply loosened.
(III) Mechanized Precision Sowing
In the Northeast spring soybean production area, sowing begins from late April to early May; in the Huang-Huai-Hai summer soybean production area, sowing is in early to mid-June; plastic film soybean can be sown appropriately earlier. In Northeast China, soybean seeders are used for equidistant precision hill sowing so that plants are evenly distributed, with a sowing depth of 3-5 cm. For ridge-cultivated soybean, narrow-row dense planting technology is adopted: generally 2 rows are planted on a 60 cm small ridge and 4 rows on a 90-105 cm large ridge, with a small row spacing of about 12 cm, and the density per hectare is increased to 375,000-450,000 plants, increasing yield by 15%-20%.
(IV) Scientific Fertilization Based on Soil Testing and Formula Fertilization
Implement a scientific fertilization method combining soil testing and formula fertilization with layered fertilization. According to different soil fertility conditions and local natural climatic conditions, determine the time and amount of chemical fertilizer application through testing and calculation. Generally, layered deep application is adopted, that is, base fertilizer is applied at 16-18 cm below the ridge, with an amount accounting for about 60% of the total fertilization amount; seed fertilizer is applied at 4 cm below the seed, with an amount accounting for about 40% of the total fertilization amount; in addition, from the beginning of flowering to the end of flowering, foliar spraying can be carried out according to growth conditions. In this way, the fertilizer requirements of soybean at different growth stages are met, and fertilizer utilization efficiency is improved.
(V) Carrying Out Scientific Field Management
The focus is on the prevention and control of soybean diseases and pests, mainly including cyst nematode, root rot, gray leaf spot, soybean pod borer, aphids, etc. For aphids, fumigation control methods are adopted to reduce the amount of pesticide used. For root rot, cyst nematode, etc., according to soil conditions and local conditions, measures such as seed coating with seed coating agents and seed dressing with 50% thiram or 50% carbendazim-thiram mixture at 0.4% of the seed amount can be used. There are many weeds in soybean fields, so low-toxicity, high-efficiency and low-residue chemical herbicides should be screened for chemical weed control, and the application amount should be controlled as much as possible. Before sowing or before emergence, combined with intertillage, carry out one soil chemical closed weed control; at the flowering and pod stage, spray herbicide once more; from the late flowering stage to the pod-setting stage, spray chemical regulators according to soybean growth conditions to ensure high soybean yield.
III. Precautions
(I) Variety Selection Should Be Appropriate
Only by combining good varieties with good methods can high yield be obtained, so excellent soybean varieties with large yield potential must be selected. Narrow-row dense planting technology should use short-stalked and semi-dwarf dense-tolerant varieties, and varieties with too long a growth period and too tall plants should not be selected, so as to ensure high yield under increased planting density.
(II) Ensure Sowing Quality
Sowing should not be too deep, nor should it be too shallow, and the depth should be consistent; otherwise, seed germination and plant uniformity will be affected.
(III) Pay Attention to Balanced Fertilization
During layered fertilization, attention should be paid to the application ratio of N, P and K fertilizers and to the different fertilizer requirements of soybean at different growth stages, and at the same time attention should be paid to the rational combination of trace elements such as B fertilizer and Zn fertilizer.