Mid-stage fertility management of rice

First, increase potassium fertilizer

Rice mid-birth is the most vigorous period for rice to absorb potassium during its lifetime, and it is also the period of maximum efficiency for accelerating vegetative growth. Potassium application at this time has the following three functions: (1) To ensure the nutritional balance of rice, promote the development of young panicles, and increase grain number to increase grain weight, thereby increasing yield. (2) Sturdy stalks, thickened epidermis, and increased resistance to disease and lodging. (3) It can improve the rhizosphere environment of rice, promote root respiration and favor the development of young panicles. The amount of potash fertilizer must be determined based on the content of available potassium in the soil. For low-potassium rice fields (ie, soil content below 80 mg/kg), if the transplant has been applied to 5-8 kg, about 5 kg will be applied in the middle of fertility; if not before transplanting Shi, it should apply 10-12 kg of potassium per acre. Potassium medium (ie effective soil K content in the range of 80 to 100 mg/kg) is applied only once in the rice field before transplanting or mid-fertility, and the available potassium is 8 to 10 kg per mu. For high-potassium rice fields (ie, the available potassium content in the soil is above 100 mg/kg), depending on the circumstances, it may not be applied or reduced. Potassium fertilizer is used during and after the cob's differentiation. The method of application can be used alone, or it can be mixed with the early panicle fertilizer and nitrogen fertilizer.

Second, reasonable irrigation

In order to do a good job in the middle of rice growth, we need to do the following three measures: First, to ensure good water layer, the period of young panicle differentiation of rice is the period with the most physiological water demand. At this time, the field surface should keep the water layer and provide sufficient rice. Moisture; Second, the water layer should not be too large. The water layer over the ambassador's lower section of the rice stretches too much and becomes thin and soft. It is not only easy to fall down, but also the internodes are fine, the number of grains per spike is small, and the empty rate is high, so the young ears Shallow water irrigation should still be carried out during the differentiation period, generally 5 to 7 cm. The third is to pay attention to soil ventilation, young panicle differentiation period is also a period of vigorous growth of rice root development, on the one hand to develop in depth, on the one hand a large number of branching roots. However, due to the high temperature at this time, the soil is prone to strong reduction reactions in the case of flooding, resulting in harmful substances that damage the root system of rice, causing root rot and premature aging. Therefore, special attention should be paid to soil ventilation while maintaining the water layer. The specific methods are as follows: 1 In general, paddy fields must supply soil oxygen by means of intermittent treatment, that is, irrigating water once or twice, drying for one or two days, and closely combining field surface water conservation with soil ventilation; 2 high groundwater level, daily For paddy fields with a leakage of less than 1 cm, the drainage channels should be dredged to reduce the groundwater level and enhance soil infiltration. 3 To properly extend the drying time for paddy fields with large amount of organic fertilizers or rice straws and root rot. Putting roots at the top of the list.