The freezing damage occurred during the seedling and returning stages of winter wheat has a great impact on the yield. The freezing damage in these two periods has frequently occurred in wheat production in Xinji and other places in recent years, causing large economic losses to farmers. The main causes of frost damage in wheat are the following: 1. Climate reasons. Due to global warming, the temperature of wheat before sowing and the temperature before overwintering are higher than in the past. As a result, some wheat grows too fast and the cold resistance weakens, causing freezing damage to wheat. 2. The quality of the site is poor. In recent years, the method of sowing wheat field sowing has generally adopted ploughing, rotary tilling, sowing, or directly using a rotary cultivator to spin plough twice and direct sowing. This kind of soil preparation method caused the soil to be loose, the water in the soil was seriously dispersed, and the heat capacity of the soil was small. After entering the winter, it caused freezing damage to the above-ground wheat leaves and roots, which was the main reason causing the large-scale cold damage of wheat. 3. Improper sowing date. In recent years, a large number of rural laborers have migrated from rural areas. After the harvest of autumn crops, regardless of the characteristics of wheat varieties, farmers sow seeds when they are solicited. Some sowing seeds need to be planted in advance, resulting in madness and prolonged growth in wheat years ago. The cold resistance is reduced. Cause a large area of ​​cold damage. 4. The use of nitrogen fertilizer is too large. Nitrogen fertilizer is an indispensable fertilizer for wheat growth, but excessive use and one-time application of basal fertilizer can easily cause seedlings to prosper, leaves are tender, and the tillers cannot store enough sugar, and they are susceptible to freezing injury during wintering.
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