Comprehensive measures to slow down the continuous cropping of soybean

In order to reduce the yield loss of continuous cropping to the minimum, we should avoid planting soybean in continuous cropping as far as possible, adhere to reasonable rotation, reduce continuous cropping and control continuous cropping. In the long run, the continuous cropping area of soybean should not be expanded indefinitely to avoid the decline of soil production capacity and the vicious circle. In the case of continuous cropping is inevitable, first arrange to meet the stubble planting, do not open the continuous cropping arrangement, and the continuous cropping can not exceed two years. In view of the reasons for the yield reduction of continuous cropping, we should focus on the regulation of nutrition and the prevention and control of diseases and insect pests, and assemble and implement the existing scientific research achievements, new technologies and practical technologies, so as to minimize the harm.

Select varieties with strong stress resistance

Under the condition of continuous cropping in different ecological regions, there are great differences in yield among different varieties. Therefore, the yield loss of soybean can be reduced by selecting good varieties with suitable maturity and tolerance to continuous cropping according to different regions according to local conditions. The selection of high-quality and high-yield varieties resistant to root rot in the eastern part of our province and high-quality and high-yielding varieties resistant to cyst nematode in the western region have good results.

Strengthen the control of diseases and insect pests

The main diseases and insect pests affecting soybean yield are cyst nematode, root rot and Phytophthora. The harm of these three kinds of diseases and insect pests is different in different regions and different years. The arid areas in the west of Heilongjiang Province are mainly damaged by cyst nematodes; the northern areas are mainly damaged by root rot and root maggots, and the harm of Sclerotinia sclerotiorum is also serious; the eastern and central and southern regions are mainly damaged by root rot and root maggots, and grubs are also seriously harmed. Excessive soil moisture in rainy years is prone to root rot; in dry years, cyst nematode occurs more seriously, and continuous cropping also aggravates the harm of soybean black spot, purple class disease, aphids and heart-eating insects.

Deep overturning in autumn and fine soil preparation

The deterioration of soil environment is another important reason for the yield reduction of continuous cropping soybean. Therefore, deep ploughing or deep loosening and fine soil preparation can improve soil water, fertilizer, air and heat conditions, promote soybean root development, enhance plant resistance, and increase the yield of continuous cropping soybean. At the same time, ploughing land can also bury insect eggs, pathogenic bacteria and grass seeds to prevent the spread of diseases and insect pests.

The soybean and wheat producing areas in the north of Heilongjiang Province should carry out the combination of turning and raking early, ridging in time, and stirring wheat stubble deep loosening or raking stubble deep loosening ridging, and the western and southern rice bean producing areas should turn or deep loose ridging as early as possible to reduce spring soil preparation as much as possible. to achieve turning, raking, ridging, suppressing continuous work, pay attention to soil moisture storage, soil moisture increase, soil moisture conservation, the eastern region should be through deep turning or deep loosening ridging to prevent waterlogging and increase temperature. Plots that have not been deeply turned over in time must be planted in inverted ridges instead of original ridges.

Apply organic fertilizer and skillfully use chemical fertilizer

The soybean plant of continuous cropping is not as strong as that of regular stubble, its fertilizer absorption capacity is weak, and the soil fertility of continuous cropping is not as good as that of regular cropping. Therefore, it is necessary to apply more fertilizer to promote plant growth and development. Organic fertilizer is a multi-element complex. The application of organic fertilizer can improve the physical and chemical structure of soil, improve soil fertility, meet the requirements of various nutrient elements in different growth stages of soybean, and create good environmental conditions for the growth and development of soybean. It has obvious effect on increasing yield, especially under the condition of middle and lower fertility. The application of organic fertilizer should emphasize quality, and the content of organic matter should reach more than 8%. Generally, 15000 to 22500 kg per hectare, combined with soil preparation in Fuqiu, should be applied at one time.

Comprehensive weeding and shaking to control grass famine

The harm of weeds in continuous cropping soybean is more serious than that in normal stubble. Malignant weeds such as Xanthium sibiricum, duck metatarsus and parasitic dodder associated with soybean spread rapidly, competing with soybean for nutrition, water and light. At the same time, due to the long-term or repeated use of long-term or repeated use of soybean field herbicides with long residual period, weeds enhance drug resistance and increase soil residual poison, resulting in poor effect of chemical weeding on malignant weeds. It also affects the growth of soybean and the following sensitive crops, and in serious cases, it can cause residual poison in soybean grains, reduce the quality and affect the export.

Using the control technology of continuous cropping

The plant of continuous cropping soybean is shorter than that of normal cropping, the root system is poorly developed and the absorptive capacity is weak. The application of rooting powder can promote root development and slow down the harm of root diseases and insect pests; the application of medicine and fertilizer can prevent diseases and insect pests as well as healthy plants; the application of organic micro-compound fertilizer and foliar topdressing can supplement the lack of nutrients and promote the healthy growth and development of plants, which plays a good role in improving the yield of continuous cropping soybean. At present, there are some soybean continuous cropping regulators, relieving agents, leaf sprays and special fertilizers, some of which are very effective and can be selected after the experiment.

After continuous cropping soybean was treated with ABT rooting powder, it could increase seedling emergence rate, reduce the number of cyst line in soil, reduce soybean cyst nematode disease, increase the number of bacteria and nodules in rhizosphere at seedling stage, increase root number, root weight, nodule weight, dry matter accumulation, grain number per plant and yield.

Improve planting shake and properly close planting

In the continuous cropping of soybean, dead seedlings, diseased plants and weak seedlings are easy to appear due to the harm of diseases and pests and malnutrition, which reduces the green area of the field. Improving the planting mode, increasing the sowing rate properly and distributing the population reasonably can increase the yield of soybean. In general, the sowing amount of continuous cropping soybeans is 8% and 10% higher than that of regular cropping soybeans. At present, the better planting methods are precision sowing on double rows on ridges, "three ridges" cultivation, narrow rows and close planting and so on.

Timely early sowing, shallow sowing, make full use of accumulated temperature to create high yield. Temperature is an important factor to limit the yield and quality of soybeans planted in alpine areas. In order to expand the planting area of high-yielding and late-maturing varieties and ensure maturity and quality, timely early sowing 5 cm surface plough layer stably through 4 ℃, shallow sowing (2 cm after town) to promote early seed germination, early germination, early emergence and early maturity. It can ensure the planting area of high-yield varieties and achieve the purpose of promoting early maturity and high yield of late-maturing varieties.