According to the law of maize fertilizer demand and practical experience in various places, the following basic principles should be mastered in maize fertilization: base fertilizer is the main fertilizer, supplemented by topdressing; Organic fertilizer is dominant, supplemented by chemical fertilizer; Nitrogen fertilizer is dominant, supplemented by phosphorus fertilizer; Re-apply base fertilizer, increase seed fertilizer and topdressing by stages. The quantity and method of fertilization should be determined according to the yield index, soil fertility foundation, fertilizer quality and utilization rate, planting density, variety characteristics and other factors. Generally, 2 kilograms of pure nitrogen, 8 kilograms of phosphorus pentoxide, 1 kilograms of potassium chloride and 1 kilogram of zinc phosphate are applied per mu. 1. applying sufficient base fertilizer

base fertilizer refers to the fertilizer applied before sowing, also known as base fertilizer, which is mainly organic fertilizer and supplemented by chemical fertilizer. The main function of base fertilizer is to improve soil fertility, loosen soil and slowly release nutrients to meet the needs of maize seedling and late growth and development. There are three methods of applying base fertilizer: strip application, spreading application and point application, among which concentrated strip application and point application have the best effect. The fertilizer is close to the root system of corn, which is easy to be absorbed and utilized by corn, with less loss and high utilization rate. As the agricultural proverb says, it is better to fertilize a large area than a line. Regardless of strip application or hole application, the fertilizer should be thoroughly pounded and mixed before application, and the fertilizer should be turned into the soil in combination with cultivated land. If nitrogen and phosphorus fertilizers are used as base fertilizer, strip application or hole application should be concentrated as far as possible according to the equipment and labor situation. When using organic fertilizer as base fertilizer, it is best to compost it with phosphate fertilizer first, and then mix nitrogen fertilizer before application. The mixed application of nitrogen, phosphate fertilizer and organic fertilizer can not only reduce the fixation of phosphorus in soil, but also make phosphate fertilizer easy to be absorbed by corn and improve fertilizer efficiency. Insoluble phosphate fertilizer and organic fertilizer are used together, which also improves the effectiveness of phosphate fertilizer and has good yield-increasing effect. Organic fertilizer as base fertilizer should be applied as early as possible. 2. Multiple topdressing < P > According to the law of fertilizer demand and growth characteristics of corn, the topdressing method for high-yield corn should be based on adequate base fertilizer and good seed fertilizer, namely, applying fertilizer at jointing stage, tapping at booting stage and tapping at grain filling stage. (1) Straw fertilizer corn is called stalk fertilizer before jointing stage, which has the function of promoting roots and seedlings and Ye Zhuang stalks. At this time, the seedlings grew vigorously, the male and female ears began to differentiate, and the demand for nutrition increased sharply. Timely topdressing fertilizer to ensure strong stems and lush leaves, and promote the differentiation of male and female ears. Generally, spring corn is about 1-2 days after transplanting, when there are 6-7 leaves, summer corn is about 7-15 days after transplanting, and when there are 5-6 leaves, it is best to apply stalk-attacking fertilizer. Fertilizer should be applied 1-15cm away from the root, 5-1cm deep in furrow, and then covered with soil. (2) Top dressing of maize during jointing stage to tasseling stage is called ear fertilizer. The maximum effect period of fertilization is in the differentiation period of female spike and floret. Generally, spring maize leaves are spread on 13-15 leaves, and summer maize leaves are spread on 11-13 leaves. At this time, it is the peak period of female ear floret differentiation in maize, and the vegetative growth and reproductive growth go hand in hand, which requires more nutrients and water, which is the key period to determine the ear volume and row number differentiation. Quick-acting nitrogen fertilizer should be used for tapping, and combined with intertillage application, the fertilizer efficiency can be quickly exerted. The frequency and time of topdressing maize are related to variety characteristics, plant growth and development, soil fertility, application amount of base fertilizer and seed fertilizer. Generally speaking, the soil fertility is high and the plants grow normally, which can be concentrated in one application before tasseling. If the soil fertility is poor, the base fertilizer and seed fertilizer are few, and the seedling growth is weak, it can be applied separately before and after jointing and before heading. At the same time, fertilization was found in the late growth stage of maize; Or after waterlogging and hail, quick-acting fertilizer can also be applied in time according to the actual situation to promote growth, prevent premature aging and win high yield.