How to prepare fertilizer and fertilize in spring?

The year is in spring, what are the characteristics of spring fertilization? How should I prepare fertilizer and fertilize?
Chinese farmers have a fine tradition of “seeing the sky, seeing the land, and seeing the crops”. Farmers and agrochemical service workers in various places must carefully do the following in combination with local conditions in the spring crop fertilization:
(1) In the spring when fertilizing, the spring fertilization should be based on various spring-sown crops such as spring corn and spring wheat, as well as nursery fruit trees and vegetables, and combined with the application of base fertilizer or seed fertilizer. Followed by winter wheat, winter rape and other winter crops, transplanting fruit trees and greenhouse vegetables and other spring crops, need timely and appropriate amount of topdressing. Since the basic characteristics of climate change in the country are that the temperature in the early spring is low and the weather is warmed by the cold, fertilization should be done without delay. Especially for spring wheat, potato, etc., which are planted earlier in the northeast, north and northwestern cold regions, the organic fertilizer should be fully decomposed, preferably in combination with the land preparation after the autumn harvest in the previous year; the ammonium fertilizer and nitrate state should be preferred for the topdressing fertilizer. Nitrogen fertilizer, because its fertilizer efficiency is faster than urea; it requires high quality, safety and proper amount of seed fertilizer, and it is applied at the same time but misplaced with the seed, that is, do not directly contact the fertilizer with the seed, otherwise it is easy to burn or reduce the product quality of the potato crop.
(2) Depending on local conditions, China has a vast territory and different agricultural conditions. The planting and fertilization in northeast and northwest areas should be combined with measures such as cold protection and drought resistance. When the temperature and soil moisture are appropriate, the time should be applied and fertilized, and the soil should be covered in time after fertilization; In the Jianghuai region, rice, wheat and rapeseed, fertilization should be combined with the excavation of “three ditch”, and the sputum should be used to prevent waterlogging, improve soil temperature and improve soil aeration conditions. The Huanghuaihai area was affected by rain and snow this spring. The soil moisture and drought are different and should be treated differently. For the general wheat field, the appropriate amount of nitrogen fertilizer should be applied in combination with watering in the jointing stage. Generally, 10 to 15 kg of urea should be applied to the mu, and 3 to 5 kg of urea can be applied to the mu in the ear, or the foliar fertilizer can be sprayed; Better wheat field, can apply nitrogen fertilizer in the greening period without irrigation, generally apply 10~15 kg of ammonium sulfate or 5-10 kg of urea, and then apply it once after jointing; good soil moisture and fertility In the Wangmiao field, which has a larger plant population, it can be fertilized after jointing and the amount of fertilizer applied is appropriately reduced.
(3) Appropriate fertilization Appropriate fertilization mainly refers to the appropriate amount of nutrient application, appropriate proportion of nitrogen, phosphorus, potassium and other nutrient distribution ratios and appropriate ratio of base fertilizer. Take food crops as an example, the current total amount of nutrient application per mu, nitrogen is 8-15 kg, rarely more than 17 kg; the amount of phosphorus applied is about half or even lower than the winter crop; The amount is mostly between the amount of nitrogen applied and the amount of phosphorus applied. The specific conditions depend on the soil conditions. The acidity of the southern acid soil is higher, the lime soil in the north is lower, and even the fertilizer can be applied in the short term. The ratio of base topdressing is that all organic fertilizers, all or most of the phosphate fertilizer, all or part of the potash fertilizer and about half of the nitrogen fertilizer are used as the base fertilizer, and the remaining fertilizers are used as seed fertilizer or top dressing; the top dressing should be applied once or in divided doses. Many farmers are accustomed to using most of the nitrogen fertilizer as the base fertilizer or the early topdressing, or even one-time application. It is easy to cause the early period, and the later fertilizer reduction and production should be corrected. If one-time fertilization is applied, the soil layer at different depths should be applied to the side when planting.
(4) Comprehensive management To do a good job in spring fertilization, it must be closely coordinated with various agricultural measures. For example, the application of base fertilizer should be combined with the improvement of soil preparation and sowing quality; topdressing should be closely coordinated with reasonable irrigation and cultivating and weeding, especially for greenhouse vegetables that have been harvested many times, such as solanaceans and melons, it is necessary to manage water and fertilizer in an integrated manner. Performed once. For greenhouse vegetables, we should pay attention to the early spring, gradually expose the shed, and strengthen the prevention and control of pests and diseases; fruit tree topdressing should be combined with the preservation of flowers and fruits and appropriate techniques for thinning and fruit thinning, and prevent excessive use of nitrogen fertilizer, resulting in long spring shoots. .