Causes and Remedy of Dead Wheat Seedlings in Winter

1. Causes of Dead Wheat Seedlings in Winter

1.1 Low temperature freezing injury. The temperature rises and falls rapidly and frequently, causing the wheat seedlings to freeze too quickly and thaw too quickly. In this alternating change of freezing and thawing, the wheat seedlings have no time to adapt, resulting in reduced physiological functions and death of the wheat seedlings.

1.2 Cold damage. In winter, the climate is cold, the soil moisture is frozen, and it is difficult for the root system to absorb water from the soil, but the stems and leaves of the wheat seedlings still lose water through transpiration, causing the water supply and demand in the wheat plant to be out of balance, which in turn causes the wheat to gradually dehydrate and die.

1.3 Densely sown seedlings. If the wheat field is sown too early and the seeding amount is large, the wheat seedlings will be crowded after tillering before winter, the ventilation and light transmission in the field will be poor, the individual growth will be weak, and the accumulated organic nutrients will not meet the needs of wheat overwintering, resulting in dead seedlings overwintering.

1.4 Return straw to the field. In wheat fields where straw is returned to the field, the soil is loose and the cold air is easy to enter, which is easy to cause the occurrence of frost damage of wheat.

1.5 Soil drought. Insufficient soil moisture, plants cannot get sufficient water supply during winter, and wheat seedlings die due to drought and water shortage.

1.6 Irrigation is too late in winter. If the winter water is too late, the following three problems will be caused, which will eventually lead to dead seedlings. First, the water content of wheat is high, and the cold current can easily cause the plant to freeze and die. Second, the ground of the frozen soil layer is cracked, the root system is pulled off, and the cold air enters the lower part of the soil layer and kills the seedling. Third, the lower layer of the soil freezes, the water cannot infiltrate, the surface freezes and the soil is hypoxic, thus wheat suffocates to death finally.

2. Remedy of Dead Wheat Seedlings in Winter

2.1 Remove dead leaves to promote photosynthesis of wheat. The dead wheat fields are covered with dry leaves, which will affect the photosynthesis of wheat. When the topsoil melts in spring, the dead leaves of the wheat field should be removed as soon as possible to promote the growth of new leaves.

2.2 Transplanting and replenishing seedlings. For the lack of seedlings caused by dead seedlings in winter, transplanting can be carried out immediately after the wheat turns green.

2.3 Topdressing nitrogen fertilizer to promote seedling rejuvenation. After the wheat turns green, apply quick-acting nitrogen fertilizer as soon as possible to promote the rejuvenation of wheat seedlings.

2.4 Adjust measures to local conditions and water in time. For the wheat fields transplanted and replenished seedlings, water should be timely after replenishing seedlings. If there is no supplementary seedlings, it should be flexibly controlled according to the ground temperature and soil moisture.

2.5 Foliar fertilization to supplement nutrition. After the wheat is damaged by freezing, it is necessary to spray humic acid, seaweed, and amino acid foliar fertilizers 1-2 times as soon as possible to supplement the nutrition of the wheat and promote the recovery of the wheat.

2.6 Loosen the soil, increase temperature and keep moisture. After the topsoil of the wheat field is thawed, loosen the soil as soon as possible, increase the temperature and keep the moisture content, promote the early growth and early development of wheat seedlings, and improve the spike rate.