Sprinkler Irrigation of Soybean at Grain filling stage

Soybean still needs some water and nutrients to promote material accumulation and maturity, increase seed setting rate and increase yield when soybean enters the grain filling stage and maturity stage. For many years, soybean has entered the grain filling stage, which is generally very dry, which has an adverse effect on the grain filling maturity of top and upper soybean. In response, some farmers used sprinkler irrigation well water to alleviate the drought during this period.

The production practice has proved that the soybean pumped and sprayed at the grain filling stage can not promote maturity, but will lead to the early withering and death of some branches and plants, thus reducing the yield.

The reason is that after seed filling, soybean enters the mature stage, because the root system is aging, the humidity is high after spraying, the ground temperature decreases, and the root conduction function is inhibited and affected, which accelerates the aging process and decline of soybean root system, resulting in partial loss of conduction function. At the same time, the humidity is too high, the root system is also easy to get soybean root rot, resulting in the whole plant drying and death, and then caused by improper sprinkler irrigation.

If sprinkler irrigation is proper, it will achieve the ideal effect. Sprinkler irrigation in the later stage of soybean should pay attention to the following points:

1. Sprinkler irrigation should be carried out before bulging. At this time, the soybean root system has not all entered the aging stage, and the ability to resist low temperature, humidity and disease resistance is strong. Spraying is not only very beneficial to soybean grain filling and rapid ripening, but also not easy to lead to root rot and so on. The soybean irrigated by sprinkler irrigation here has full grains and a large increase in yield, which is the key period for the yield increase of soybean.

2. Choose the time of sprinkler irrigation. If the weather temperature is high, high temperature sprinkler irrigation (except river water) should be avoided, and spraying in the morning and evening should be chosen to reduce the temperature difference between soybean and well water.

3. In the later stage, sprinkler irrigation should reduce or shorten the sprinkler irrigation time and reduce the high soil moisture as much as possible. When soybeans enter the late stage of grain filling, we should pay more attention to mild humidity when pumping well water, so as not to cause root rot of soybean. When the temperature is high, sprinkler irrigation should be connected with the moisture in the soil and should not be sprayed. When the temperature is on the low side, the intensity of sprinkler irrigation should be less than the infiltration rate of soil, and it is appropriate that the surface does not produce runoff and stagnant water, so as to meet the needs of soybean grain filling.

4. Sprinkler irrigation and fertilization are carried out simultaneously. In the late stage of sprinkler irrigation, the soybean should be sprayed with foliar fertilizer twice in time to promote grain filling and maturity. Soybean can be sprayed with 7.5ml 10 kg urea or 1.2 kg potassium dihydrogen phosphate per hectare to supplement the nutrients that can not be provided in time due to root aging, and at the same time promote and improve leaf function, prolong vitality and improve photosynthetic efficiency, so as to increase seed setting rate and yield.