Problems that should be paid attention to in winter irrigation of planting wheat

Winter irrigation is one of the effective practical experiences in increasing production of winter wheat. In order to carry out winter irrigation correctly, we must consider the following three factors, namely, temperature, soil moisture and seedling condition.

The suitable temperature for winter irrigation is about 3 ℃ of daily average temperature. Winter irrigation is too early, the temperature is still high, evaporation is large, can not play the role of irrigation, increase soil moisture, at the same time, it will also cause wheat seedlings to grow too long, not anti-freezing; winter irrigation is too late, the temperature is too low, soil freezing, water can not seep, often occur Lingtai, wheat seedlings will be frozen or suffocated to death. When the daily average temperature of winter irrigation is below 0 ℃ or close to 0 ℃, there are different degrees of frost injury after irrigation. After winter irrigation, the cold current comes, and when the air temperature drops below 0 ℃, the soil temperature of winter irrigation is higher than that of non-winter irrigation, which is of great benefit to ensure that wheat seedlings survive the winter safely.

In terms of soil moisture, winter irrigation is required if it is less than 70% of the field capacity; if it is higher than 70%, winter irrigation or no winter irrigation can be postponed appropriately, but measures to loosen soil and preserve soil moisture should be strengthened to increase soil temperature and promote wheat roots to root down to cultivate strong seedlings.

The seedling condition during winter irrigation is also an important condition to consider whether or not to carry out winter irrigation. Prosperous seedlings are generally not short of water and fertilizer, and there is no need to irrigate them in winter. Weak seedlings (especially late sowing wheat and single seedling) should not be irrigated in winter to prevent silting seedlings, Lingtai and freezing damage to wheat seedlings. Even dead seedlings. For this kind of weak seedlings, winter water can be changed to separate water, adjust fertilizer with water, attack seedlings with fertilizer, and make wheat seedlings from weak to strong. The soil permeability of the wheat field in the wetland is poor, and the wheat seedlings are easy to turn red, yellow, or even suffocate to death after winter irrigation. for this kind of wheat field, under the condition of water before irrigation and sowing, we should take measures to strengthen ploughing and preserving soil moisture after tillering, so it is not necessary to consider winter irrigation.

The amount of irrigation in winter should not be too large, so as to avoid stagnant water on the ground and form an ice crust in case of low temperature, resulting in freezing of the aboveground parts of the plant, asphyxiation of roots, death of tillers and reduction of yield.

After winter irrigation, the soil must be loosened at the right time to avoid the harm of cracking due to soil consolidation. Special attention must be paid to late sowing wheat. In addition to preserving soil moisture and preventing soil consolidation, cracking and aeration, ploughing and loosening soil can also increase the soil temperature by about 10 centimeters by 1 ℃, which is beneficial to the growth of seedlings.