Home › Growing Techniques › Article

Why do continuous and alternating soybean cropping reduce yields? Cause analysis and countermeasures

Growing Techniques 0 views
With China's accession to the WTO and the opening-up policies of the grain market, the problem of continuous and alternating soybean cropping has become increasingly serious, and the yield reduction increases as the number of consecutive cropping years rises. According to surveys and research, alternating cropping reduces yield by 6.1%, one year of continuous cropping by 9.9%, two years of continuous cropping by 13.8%, and three years of continuous cropping by 19.0%. Moreover, in continuous and alternating cropping soybeans, the 100-seed weight decreases, the rate of diseased seeds and insect-damaged seeds increases, and commercial quality drops significantly. With long-term continuous cropping of more than 3 years, the protein content of soybeans increases markedly while the fat content decreases markedly. According to research by scientific research departments

With China's accession to the WTO and the opening-up policies of the grain market, the problem of continuous and alternating soybean cropping has become increasingly serious, and the yield reduction increases as the number of consecutive cropping years rises. According to surveys and research, alternating cropping reduces yield by 6.1%, one year of continuous cropping by 9.9%, two years of continuous cropping by 13.8%, and three years of continuous cropping by 19.0%. Moreover, in continuous and alternating cropping soybeans, the 100-seed weight decreases, the rate of diseased seeds and insect-damaged seeds increases, and commercial quality drops significantly. With long-term continuous cropping of more than 3 years, the protein content of soybeans increases markedly while the fat content decreases markedly.

According to research by scientific research departments, the soil nutrient consumption and uptake of soybeans in normal rotation versus continuous and alternating cropping, and the relationships among root exudates, root stubble decomposition products, rhizosphere microorganisms, soil-borne diseases and pests, and the rhizosphere environment and plant metabolism. The main reason for yield reduction in continuous and alternating soybean cropping is severe root diseases and pests. Due to the severe damage from root diseases and pests and the deterioration of the soil environment, the normal physiological activities of soybean roots are disrupted, root physiological vigor is reduced, the symbiotic nitrogen fixation system is destroyed, root absorption capacity is inhibited, plant metabolism is weakened, plant growth is slow, dry matter synthesis and accumulation are reduced, and soybean yield and quality decline.

When continuous and alternating soybean cropping is unavoidable, strong technical measures must be actively adopted to mitigate the harm of continuous and alternating cropping.

1. Rational crop rotation, minimizing continuous cropping as much as possible and maintaining an appropriate proportion of alternating cropping.

2. Select varieties with strong stress resistance. This can cause variation in rhizosphere microorganisms and physiological races adapted to diseases and pests, effectively reducing the harm of continuous and alternating cropping.

3. Rational tillage and increased fertilizer application to improve the soybean growing environment, carry out autumn soil preparation, and apply trace element fertilizers to supplement the deficiency of trace elements in continuous and alternating cropping fields, so as to mitigate the harm of continuous and alternating cropping and increase yield; this is an effective approach.

4. Appropriately increasing sowing density, increasing the number of retained plants, and giving play to the population effect are effective measures to mitigate the harm; generally, the sowing rate should be increased by 8-10% compared with soybeans in normal rotation, and sowing quality should be improved.

5. Strengthen field management and control diseases, pests, and weeds. The reasons for reduced yield and declining quality in continuous and alternating cropping soybeans are many-sided and result from the interaction of various unfavorable factors. Therefore, to grow continuous and alternating cropping soybeans well, it is necessary to start from many aspects, such as improving the soybean growing environment, meeting nutritional needs, enhancing the soybean's own resistance, and strengthening disease and pest control, and to adopt comprehensive cultivation techniques, striving to mitigate the harm of continuous and alternating cropping to the greatest extent possible.

Related Articles