Grasping the key to winter wheat fertilization

Since the beginning of the spring, the cold current frequently invaded the snow several times, causing the temperature of the winter wheat planting area to be unable to rise steadily. This has had a great impact on the early growth of winter wheat this year.

Agrochemical service experts believe that due to the climatic characteristics of the previous year, the current winter wheat seedlings are generally weaker than the same period last year. The management of water and fertilizer after spring rejuvenation is very important. Grasping well can be beneficial to the growth and development of the middle and late stages, and make up for the losses caused by the bad weather in the early stage. But if you don't do well, it will be the worst. At present, the function of fertilizer and water management during the period of wheat rise is to focus on the number of effective spikes, and then the joint attack is the main attack number and the final weight is heavy. In principle, it is necessary to interlock, not to make mistakes, and there is no contradiction between individuals and groups, number of spikes and number of grains, and grain weight. It is still possible to strive for high yields in summer.

Although climate change is not artificially controllable, the main measure that can be regulated now is the management of fertilizer and water. Therefore, farmers must grasp the key to fertilization in spring. The following is a breakdown of the key techniques of spring winter wheat topdressing into fertilizer application, fertilization period and fertilization method:

Grasping the core technology of nitrogen fertilizer application

The amount of nitrogen fertilizer is linked to the target output, and the yield level mainly depends on the comprehensive factors such as soil basic fertility and variety. From the different climate ecology and production level, China's winter wheat production area is divided into three regions:

The winter wheat yield in the North China Plain is between 500 and 600 kg/mu, and the recommended nitrogen application rate for spring topdressing is 6-8 kg(N)/mu. For the wheat field with a target yield of 400-500 kg/mu, the recommended nitrogen application rate for spring topdressing : 5~7 kg (N)/mu, for wheat fields below 400 kg/mu: 4~5 kg(N)/mu.

If the amount of base fertilizer is too high in the wheat field in this area, the lower limit can be applied to the amount of spring topdressing. If the base fertilizer is applied with organic fertilizer, the lower limit is also used. The proportion of base and topdressing can be half of each. Topdressing must be carried out twice.

In the case of divided fertilization, it is advisable to choose ammonium bicarbonate for fertilizer and urea for joint fertilizer.

The winter wheat in the middle and lower reaches of the Yangtze River has a target yield level of 500 kg/mu or more, and the spring has applied 7-8 kg (N)/mu of nitrogen fertilizer; the wheat field with a yield of 400-500 kg/mu, and the nitrogen fertilizer of 6-7 kg in the spring (N) /mu; the yield level is 300~400 kg/mu of wheat field, and the nitrogen fertilizer is 5~6 kg(N)/mu in spring.

The principle of using nitrogen fertilizer in the northwest dryland winter wheat is based on base fertilizer and supplemented by topdressing. When the output level is above 300 kg/s, the nitrogen fertilizer in the spring is 4~5 kg(N)/mu; the production level is 200~300 kg/mu, and the nitrogen fertilizer in the spring is 3~4 kg(N)/mu; the yield level In the spring of 200 kg / acre, the application of nitrogen fertilizer in the spring 3 to 4 kg (N) / mu.

Wheat field spring dressing period

In the middle and high-yield wheat fields, the risk of nitrogen application in two springs is small. Generally, the first application rate is slightly less than the second time. The first suitable topdressing time is in the early stage of the rise, and the second top dressing time should be in the middle of the jointing stage. Five leaves (seed differentiation of panicles). The role of the first top dressing is the number of main attacking spikes. If too much is applied, a large number of ineffective tillers will grow, which not only wastes nutrients but also does not benefit or increase production. If the nitrogen fertilizer is applied all at once without dividing it twice, it will result in less effective ear and less grain, and the growth becomes a top-heavy plant type, which is easy to fall and has a low grain weight.

Application method

It is best to use mechanical sowing fertilizer or artificial animal power to spread the fertilizer to achieve the purpose of covering the soil. In the case of poor soil moisture, the top dressing should be irrigated at the same time, with water and fertilizer.