How to fertilize rice, wheat, corn and other field crops?

According to different soil fertility conditions, in general, about 40kg urea is applied per mu.

Different crops use different amounts of urea. Take rice and wheat for example.

1. The principle of rice fertilization should be that organic fertilizer and phosphate fertilizer are used as base fertilizer, potassium fertilizer is mainly used as tiller fertilizer, and nitrogen fertilizer is applied evenly in multiple times. Special attention should be paid to strong bracts and strong seed fertilizers, and at the same time, we should focus on big ears and big grains.

(1) Organic fertilizer is the main base fertilizer. It is determined that 50%-60% of nitrogen and 70% of phosphorus and potassium absorbed by rice come from soil. Insufficient fertilization will consume too much potential nutrients in the soil and reduce soil fertility. Increasing the application amount of organic fertilizer is an important way to maintain and improve soil fertility. Therefore, rice production should emphasize the accumulation of soil and miscellaneous fertilizers, develop aquaculture, apply more column fertilizers and various green fertilizers, and advocate harvesting and returning straw to the field, so that the use of organic fertilizers accounts for 40% of the total fertilization.

(2) Apply a proper amount of tillering fertilizer early, and apply 6-7.5 kilograms of urea for the first time per mu; Every 7 days or so, according to the seedling situation, apply secondary tillering fertilizer to the fields with poor growth, with urea below 4 kg per mu; Apply 5-7.5 kilograms of potash fertilizer to the land with less organic fertilizer and insufficient potash fertilizer per mu.

(3) According to the application of ear fertilizer, both flower-promoting fertilizer and flower-protecting fertilizer can be applied, and 5 kilograms of urea can be applied once per mu. There is a great demand for potash fertilizer in rice. After drying in the sun and rehydrating, combined with topdressing nitrogen fertilizer, about 2.5 kilograms of potassium fertilizer was applied per mu, and the yield increase effect was obvious.

(4) Before heading, the leaves of the seedlings are too light, and 2-2.5 kilograms of urea should be applied per mu, and 2.5-3 kilograms of urea should be applied per mu in the land that falls yellow prematurely after heading. For normal growth of hybrid rice, only 500-750g of urea and 50kg of water need to be mixed as grain fertilizer.

2. Urea contains 46% nitrogen and is an ideal fertilizer for rice. However, due to improper and unreasonable application, it not only caused waste, but also had no effect, leading to the occurrence and epidemic of rice diseases.

(1) Before ploughing with deep base fertilizer in autumn or after ploughing in spring, evenly spread urea on the field surface, then plough it in autumn and bury it in the soil. Base fertilizer is applied deeply, and the fertilizer effect is long, so it should not be used too much, so as to avoid gluttony and lodging of rice in the later stage.

(2) Apply tillering fertilizer 7 10 day after rice planting, and apply 57kg urea per mu.

(3) "Urea" fertilizer can only be sprayed one month after seeding. Generally speaking, there is no strict boundary between fertilizer for foliar fertilization and fertilizer for root soil fertilization. In principle, all fertilizers are harmless and contain nutrients.

(4) When fertilizing late rice seedlings, it is appropriate to apply 150 kg ammonium sulfate or 75 kg urea per hectare two days before transplanting.

wheat

(1) winter wheat fertilization technology, it is generally believed that every 100 kg of wheat seeds needs to absorb about 2.8-3.2 kg of pure nitrogen, 1- 1.5 kg of phosphorus and 2-4 kg of potassium, and the ratio of nitrogen, phosphorus and potassium is about 1: 0. Among them, nitrogen and phosphorus are mainly concentrated in seeds, accounting for 76% and 82.4% of the total plant content respectively, and potassium is mainly concentrated in stems and leaves, accounting for 77.6% of the total plant content.

(2) There should be enough nitrogen and appropriate phosphorus and potassium nutrition in wheat seedling stage. According to the growth law and nutritional characteristics of wheat, base fertilizer should be applied again and topdressing should be done early. Generally, the amount of base fertilizer should account for 60% ~ 80% of the total fertilization amount, and it is appropriate to account for 40% ~ 20% of topdressing.

(3) According to the data of Soil and Fertilizer Research Institute of Qinghai Academy of Agriculture and Forestry, the output of spring wheat in this province is 7500 kg/ha. Every 100 kg of grain needs about 2.5-3.0 kg of nitrogen, 0.78- 1. 1.7 kg of phosphorus and 0.9-4.2 kg of potassium. The ratio of nitrogen, phosphorus and potassium is 2.8: 1:3. 15. The absorption of nitrogen, phosphorus and potassium by spring wheat has two peak periods: the first is from jointing to booting stage, and the second is from flowering to filling stage, the former is slightly higher than the latter. From emergence to milk ripening, from jointing to milk ripening, the absorption rate of phosphorus has been rising. According to the growth law and nutritional characteristics of spring wheat, base fertilizer should be applied again and topdressing should be done early.