Rice "three Fertilizer" and its Application skills

Scientific fertilization is one of the important measures to achieve high quality and high yield of rice. However, rice fertilization is a highly technical work, which must be flexibly mastered in practice because of variety characteristics, soil fertility, climatic factors and cultivation conditions. As we all know: the demand for fertilizer of rice is shown in the nutrition period, the nutrition critical period and the nutrition maximum efficiency period. For example, the growth period of early rice is short, the amount of fertilizer required is relatively less, and fertilization should be early and concentrated. If the growth period of middle rice and late rice is longer, the amount of fertilizer needed is large, and the absorption intensity is high, the times of topdressing should be increased and the proportion of topdressing should be increased. The critical period of nitrogen, phosphorus and fertilizer in rice generally appeared in the three-leaf stage, and sometimes the critical period of nitrogen and potassium also appeared in the stage of young panicle differentiation and panicle formation. The maximum nutritional efficiency period of rice occurs in the long panicle stage, which is not only the most exuberant stage of vegetative growth and reproductive growth, but also the key period of fertilizer demand. According to research, for every 100 kg of rice, it is necessary to absorb 1.6-2.5 kg of nitrogen, 0.8-1.2 kg of phosphorus and 2.1-3.0 kg of potassium from the soil. According to the above fertilizer characteristics of rice, on the basis of sufficient base fertilizer, we should pay attention to the application of "three fertilizers", that is, tillering fertilizer, panicle fertilizer and grain fertilizer.

First, apply tiller fertilizer timely and early. The topdressing of rice from transplanting to young panicle differentiation is called "tillering fertilizer". Tillering fertilizer requires early topdressing time and sufficient quantity, and the general amount of tillering fertilizer accounts for 50-60% of the total topdressing fertilizer. Because the tillering stage is the first peak period of absorbing nitrogen nutrition in rice life, and because the air temperature, water temperature and soil temperature are low in the early growth stage of rice, and the nutrient release is slow, the amount of topdressing is too little to meet the nutrient needs of rice. Only timely and early application is beneficial to early tillering and more tillering, reduce tiller node position, and create conditions for panicle length and grain weight. Tillering fertilizer was applied 7-10 days after rice planting, and urea was applied 5-7 kg per mu. If the base fertilizer is insufficient, it can be increased appropriately, but avoid excessive topdressing to prevent excessive growth in the middle and later stage, greedy green and late ripening.

Second, skillfully apply panicle fertilizer. The topdressing of rice from young panicle differentiation to pre-heading is called "panicle fertilizer". This period is the second peak of nitrogen uptake. Scientific application of panicle fertilizer can not only protect flowers and grains, promote larger grains per panicle, but also prevent greed and lodging. Technically, it is necessary to achieve several points: first, the fields with good soil fertility, sufficient bottom fertilizer and many tillers are not applied; second, the leaves do not hang dew in the morning, the leaves are straight at noon, and the leaves are yellowish; and third, they are not applied in rainy days and rush to apply in sunny days. The application time is rice round culm stage, urea 3-4 kg per mu, and 0.2-0.3% potassium dihydrogen phosphate solution 50 kg per mu evenly sprayed on the leaf surface.

Third, apply grain fertilizer as appropriate. The topdressing of rice after heading is called "grain fertilizer", also known as "strong seed fertilizer". Appropriate application of grain fertilizer can effectively prolong the functional period of leaves, prevent premature senescence and increase grain weight. However, it should be noted that the seedlings are not applied if they are not yellow, on cloudy and rainy days, and in fields with diseases. Choose to spray 1% urea solution on a sunny afternoon, or 1% of Huimanfeng active liquid fertilizer, 50 kg per mu. For the rice fields with sheath blight and febrile disease, the pesticides such as sclerotia, different rice plague, Wenkujing, Nongkang 120 and carbendazim should be sprayed alternately to prevent and control them in time.