Management techniques for late wheat in early spring

Due to the heavy rainfall encountered during the sowing period before and after the "National Day" last year, wheat farmer Cold Dew sowed seeds only after the solar terms, forming late wheat. In addition, the rainfall at that time also delayed the growth of wheat sown at normal time, and also formed late wheat. As a result, more than half of the 1.1 million mu of wheat sown in this city last year were late wheat, and the growth characteristics of late wheat were different from those of ordinary wheat, so the management techniques in early spring were also different.

Evening wheat generally refers to the wheat sown after the cold dew festival. Its growth characteristics are different from those of wheat sown at the right time, such as young overwintering seedlings, less tillers, less secondary roots and short stems in the ground. The root group construction period of late wheat is mainly in the green stage. The main reasons for the yield reduction of late wheat in production are as follows: first, the number of ears per mu is insufficient; second, the lack of phosphate fertilizer leads to the emergence of small old seedlings; third, the practice of late sowing and early tube is adopted in early spring management, early watering, more watering and more fertilization. Due to too much water in the green period, it often causes cold ground, soil plate and alkali return, which is disadvantageous to the development of root system, postpones the growth of wheat, leads to late heading and low grain weight due to high temperature in the later stage. Therefore, the early spring management of late wheat mainly focuses on improving soil temperature, preserving soil moisture and promoting early emergence of seedlings.

1. Soil removal is carried out. Remove and paddle after watering or rain to conserve soil moisture. This is the main management measure of water saving and drought resistance of early spring wheat.

two。 Dingling is applied with chemical fertilizer, especially phosphate fertilizer. Because the temperature in early spring is low, the ability of soil phosphorus supply is weak, at the same time, the root group of wheat is small, and the ability of phosphorus uptake is weak, so the response of late wheat to phosphorus in early spring is more sensitive. If phosphate fertilizer is insufficient, it is easy to form small old seedlings, resulting in reduced yield of late wheat. Generally, the yield of late wheat is more than 400 kg per mu, and it is suitable to apply 35 kg of urea, 25 kg of diammonium phosphate and 15 kg of potassium sulfate during the whole growth period. 60% of the total nitrogen and all phosphate and potassium fertilizers were used as base fertilizer. For the wheat field with insufficient base fertilizer, the method of ditching fertilization can be used to top fertilizer before the soil in early spring, and the insufficient part can be made up.

3. Delay the time of fertilizing and watering in spring. For the wheat field with sufficient soil moisture and timely winter irrigation before winter, the suitable watering time of late wheat can be made. according to the open field of new tillers (latent tillers), the new root grows about 1.5 cm and the ear differentiation enters the two-edge stage, the general time is in the first ten days of April. 40% of the total nitrogen fertilizer is applied after watering. If the soil moisture is insufficient, it can be managed early according to the growth of wheat seedlings.

4. Toppling prevention and weeding. Because the sowing amount of late wheat is relatively large and the root group in early spring is small, it is easy to lodge if it is not well managed, so we should pay attention to prevent lodging and weeding from rising to jointing stage.