Characteristics of fertilizer requirement of winter wheat The key stage of nitrogen topdressing is jointing stage. After the winter wheat turned green and headed, the vegetative growth and reproductive growth went hand in hand, and the nutrient absorption increased rapidly, which was the key period to determine the effective panicle number and grains per panicle of wheat.
Therefore, except all organic fertilizer, phosphorus, potassium fertilizer and a part of nitrogen fertilizer as base fertilizer, most nitrogen fertilizers are mainly topdressing from the beginning to the jointing stage.
The contradiction between individuals and groups is prominent. Winter wheat is an overwintering crop, tillering per plant, and the number of effective panicles per mu is closely related to the yield per mu.
However, there is a reaction to nitrogen fertilizer at tillering stage, and excessive application will easily lead to the increase of ineffective tillers and the lodging of plants.
The growth and tillering of wheat are also related to variety characteristics, sowing quantity and quality, soil fertility and water content, climatic conditions and other factors.
Therefore, topdressing in spring should be integrated according to local conditions.
Rotation fertilization should take into account the rotation of winter wheat and summer corn, and the characteristics of rotation fertilization should be considered, and the two crops should be regarded as one.
Scientific research and practice have proved that the amount of nitrogen applied to the two high-yield crops is roughly the same, but phosphorus fertilizer should be mainly applied to winter wheat and potassium fertilizer should be mainly applied to summer corn.
Proper deep ploughing before wheat sowing can not only meet the needs of winter wheat, but also create favorable conditions for the root growth of summer maize.
The specific practice of winter wheat fertilization technology is to first define the planting area where the fertilization field is located, and then take the average yield increase 10%- 15% of continuous high yield for nearly three years as the target yield, and then calculate the corresponding fertilization amount.
Regarding fertilizer distribution, organic fertilizer and phosphorus and potassium fertilizer are used as base fertilizers; It is emphasized that the application of nitrogen fertilizer should be postponed appropriately. Except for all rain-fed dry wheat areas in the west and 55% rain-fed winter wheat areas in North China, the nitrogen application rate of base fertilizer in most other wheat areas does not exceed half of the total amount, and the rest is mainly used as topdressing, from initial application to jointing stage.
Adjust measures to local conditions.
The seedling condition of winter wheat is a comprehensive expression of soil fertility, fertilization level and production management. On the basis of table comparison, different water and fertilizer management measures were taken according to the specific seedling conditions.
Matters needing attention in winter wheat fertilization Summarizing the current situation of winter wheat fertilization in various places, we can find 7 problems that farmers should pay attention to avoid.
First, the amount of organic fertilizer application is insufficient.
With the improvement of rural conditions, farmers' enthusiasm for accumulating farmyard manure has decreased, and the aquaculture industry has gradually changed from decentralized farming to large-scale farming, and the amount of livestock manure of farmers has decreased, while the utilization rate of livestock manure in large-scale farming is not high, resulting in insufficient application of organic fertilizer.
Second, the structure of chemical fertilizer application is unreasonable.
Many farmers do not consider the soil nutrient content and wheat yield level when determining the amount of fertilization, and the phenomenon of blind fertilization is more serious.
Especially with the increase of wheat total output, the amount of chemical fertilizer is also increasing, in which the amount of nitrogen and phosphorus fertilizer is generally excessive, which leads to the increase of ineffective tillers, the thinning of stems, the decline of lodging resistance, cold resistance and disease resistance, and often suffers from freezing injury in winter, cold in late spring, and the aggravation of pests and diseases in the middle and late period, which is easy to lodging, thus affecting the yield.
Third, return the straw to the field without adding nitrogen fertilizer.
Returning straw to the field is an effective measure to solve the shortage of organic fertilizer, but many farmers have not mastered this technology and have not applied nitrogen fertilizer after returning straw to the field.
In the process of straw decay, a certain amount of nitrogen should be absorbed and consumed. If nitrogen fertilizer is insufficient, straw rot and wheat seedling growth will compete for nitrogen, resulting in "yellow weak seedlings"
Fourth, the fertilization method is unreasonable.
There is a "one shot" fertilization method in some middle and low yield fields or poor soil areas in winter wheat producing areas, that is, all chemical fertilizers are applied to the soil at one time during the soil preparation and sowing period, and no topdressing is required during the growth period.
On the one hand, due to the limitation of irrigation conditions, fertilizer and water are not coordinated, and "one shot" affects fertilizer efficiency; On the other hand, the nitrogen requirement of winter wheat before turning green is less than 30%, but in many areas, 40% ~ 50% of nitrogen fertilizer is applied at one time during turning green, even as high as 70%.
The fifth is improper topdressing period.
Topdressing in most winter wheat areas is carried out in the turning green period, and early spring is the key period for spring tillering and basal internode elongation of wheat. Premature topdressing often leads to too many ineffective tillers, too large wheat field population, too thin stems and too long basal internodes. It will also cause diseases such as field closure, poor ventilation and light transmission, powdery mildew and so on in the middle and late stage of wheat growth, which will lead to lodging easily in the later stage and affect the yield and quality of wheat.
The sixth is to ignore the application of trace element fertilizers.
Trace elements are also essential nutrients for the growth and development of winter wheat.
Lack of some trace elements in winter wheat will lead to poor growth and yield reduction.
In recent years, with the increase of wheat yield, the consumption of soil trace elements has increased, and many plots are short of trace elements, especially those that do not apply organic fertilizer or have insufficient application of organic fertilizer.
Seventh, blindly apply new fertilizers.
At present, the quality of various new fertilizers on the market is uneven.
Some of them are not high in scientific and technological content and over-hyped, which leads to farmers' unclear understanding and blind application under the condition of unclear fertilization direction and application method, resulting in reduced production and economic losses.
The above is the information about the characteristics of winter wheat fertilizer demand and how to apply fertilizer. I hope the above information can help you.