Key points of fertilization techniques for winter wheat

The high yield of wheat is strongly dependent on soil fertility. Wheat fertilization should pay attention to the following aspects: first, the amount of nitrogen fertilizer in wheat field should not be too large, nor too small. If there is too much nitrogen fertilizer in the early stage, it is easy to cause the early growth to be too prosperous, and the lodging in the later stage to reduce the yield; if the nitrogen fertilizer is too little, then the wheat plant can not reach the physiological state of safe overwintering, and the wheat yield will be reduced if the wheat is frozen seriously. Second, wheat is particularly sensitive to phosphorus. If phosphorus is deficient in the three-leaf stage, it will lead to less secondary roots, delayed tillering or no tillering. Phosphorus deficiency after three-leaf stage will delay heading, flowering and ripening, reduce the number of grains per spike and decrease 1000-grain weight. The number of spikes per mu, grain number per spike and 1000-grain weight are the three elements of wheat yield. If the three factors decrease at the same time, the yield reduction will become a foregone conclusion. Third, potash fertilizer determines the stress resistance of wheat, such as drought resistance, cold resistance and lodging resistance. When wheat is deficient in potassium, the concentration of wheat cell sap decreases and the freezing point of wheat cell sap increases, which is prone to freezing injury.

Knowing the above characteristics of wheat fertilizer, it is easy to fertilize wheat. Through the research experience of soil testing and formula fertilization for wheat in our bureau in recent years, a better method of wheat fertilization is obtained.

In the irrigated winter wheat area, before sowing the wheat, the organic fertilizer and 60% of the chemical nitrogen fertilizer needed for the whole growth period, 100% phosphorus and potassium fertilizer were ploughed into the soil, and fertilized according to the local soil and climatic conditions combined with the soil analysis of the local plant protection station. in general, 30-40 kg compound fertilizer can be applied.

In the arid winter wheat area, due to the low precipitation during the wheat growth period, the effect of shallow topdressing is poor, so there is generally no topdressing. On the other hand, organic fertilizer and chemical fertilizer were applied once and for all before wheat sowing.

Topdressing

In the irrigated winter wheat area, in the early spring wheat turning green and jointing stage, combined with spring irrigation, topdressing back green fertilizer. Topdressing is nitrogen fertilizer, and the application rate is 40% of the nitrogen required during the whole growth period.

1. Principles of fertilization

The main results are as follows: (1) applying sufficient base fertilizer and increasing organic fertilizer to increase the content of soil organic matter, fertilize the soil and enhance the ability of soil fertilizer and water conservation.

(2) heavy application of jointing fertilizer (topdressing) according to the seedling condition, the wheat has more tillers, the seedling condition is good and the growth is vigorous, so it should be applied late appropriately, while the wheat has few tillers, the seedling condition is not good and the growth is weak, so it should be applied early.

(3) light application of panicle fertilizer is not suitable for wheat fields with sufficient water and fertilizer and lodging tendency. The seedling condition is good, can apply little or no panicle fertilizer, lack of water and fertilizer, wheat with premature senescence tendency should be applied panicle fertilizer, spike fertilizer can be applied to quickly supplement nutrients, increase grain weight, strong stalk to prevent toppling.

(4) foliar topdressing is the dry-hot wind-prone season in late May every year. Spraying fertilizer on the leaf with 0.2% potassium dihydrogen phosphate for 1-2 times with an interval of 5-7 days can effectively prevent the harm of dry and hot wind.

2. Fertilizer application rate of wheat.

The amount of nutrients absorbed by wheat grains per 100kg production is determined by soil, climate (rainfall, temperature, light) varieties, yield and other factors. The statistical results of the Institute of soil and Fertilizer, Chinese Academy of Agricultural Sciences are as follows: n 3.0 kg/100kg grain, P 0.40-0.65kg/100kg grain, K 1.7-3.3kg/100kg grain.

Determination of Fertilizer Application rate for Wheat

Most of the nutrients absorbed by wheat come from the fertilizers applied in the current season, but a considerable part of the nutrients are provided by the soil. In addition, 100% of the fertilizers applied in this season are not absorbed by plants, some or most of them are absorbed, fixed, or lost in various forms by the soil, so there is a problem of fertilizer utilization. Therefore, it is very necessary to apply fertilizer scientifically and rationally.