Reasons and Prevention of Winter Wheat Seedlings in Winter and Spring
I. Causes of dead seedlings in winter and spring in wheat 1. Endogenous origin refers to the ability of wheat plants to resist cold and drought. Using varieties with poor cold resistance can easily cause dead seedlings. Individual seedlings that sow prematurely and pre-winterly differentiated into the Erlang period have reduced their ability to tolerate cold. They often die severely in the event of frost damage. Some late weak seedlings have less accumulated sugar, and are often susceptible to cold and drought. 2. Exogenous factors refer to various factors other than the body of wheat plants, such as unfavorable weather, soil conditions, and improper cultivation measures. For example, if there is less rainfall in summer and autumn, the soil bottom is insufficient, and in winter and spring, there is less rain and snow, more cold wind, and increased soil drought, so that the wheat tillering festival is in the cold and warm rapidly changing soil, causing wheat to dehydrate physiologically and die. The winter is weak, shallow varieties of childbirth, vulnerable to temperature and temperature differences. Insufficient sowing, the growth and development of wheat strains, and sowing too late, too deep, too dense and easy to form weak seedlings, is not conducive to safe winter wheat, in the case of insufficient bottom water, do not pour winter water, resulting in the early cold and death seedling. Second, to reduce the cultivation of dead seedlings measures 1. Selection of cold-resistant varieties used in winter is a good, cold-resistant varieties are effective measures to prevent freezing dead seedlings, all localities should be adapted to local conditions, introduction must first understand the characteristics of varieties, not only have high yield Sex, but also have a certain resistance to cold, at least in most local years can safely winter, before planting. 2. Seedling irrigation Early cropping wheat fields with insufficient saggers can be watered well during the tillering stage. If the soil fertility is insufficient, a small amount of chemical fertilizers can be topdressed to reach the early stage of seedling growth, and the deep roots are large, which is conducive to safe wintering. For late-seeding seedlings, the main contradiction is that the accumulated temperature is insufficient, and management should focus on cultivating loose soil to increase ground temperature and preserve floods. Seedlings should not be watered, otherwise it will affect the upgrading of wheat seedlings. 3 timely winter irrigation winter irrigation can form a good soil moisture environment, adjust the soil nutrients in the plough layer, increase the heat capacity of the soil, winter irrigation so that the topsoil sealed tightly, promote rooting, more tillers, grow up, eel, seedlings, reduce winter cold, Dead seedlings caused by drought and pouring winter water are not only beneficial to wintering and protecting seedlings, but also can mitigate the adverse effects brought about by the cold, drought, and severe changes in temperature in early spring. Therefore, it is an important measure to prevent dead seedlings in winter and spring. Watering winter water should be appropriate. It is advisable to use the water at night when the temperature is 4°C. When the weather is lower than 4°C, there is a risk of freezing injury during winter irrigation. The winter irrigation should be controlled flexibly according to soil quality, seedling condition, and lyricism. The clay should be properly poured in early, to prevent the water from infiltrating and freezing before freezing. Sandy land should be poured late, and part of the wetlands, rice fields, or wheat fields at the bottom can be poured. However, for feed-rich wheat fields, winter water must be poured to crush the soil and freeze the pests. 4. Timely pressure wheat can break the soil mass, break cracks, and practical soil, so that the wheat root and the soil are tightly combined to promote the development of the root system; the pressure wheat also has the function of lifting and protecting the earthworm. 5. Appropriate coverage of winter sand cover Gamai, soil cover Gamai, can deepen the tillering section into the soil depth and protect the leaves of the near-ground, reduce soil moisture evaporation, improve the water conditions at the birthing node, play a role in insulation and antifreeze. Generally, 1～2cm soil can play a good anti-freezing and seedling preservation effect. It is necessary to enter the Qing ridge by the spring and remove the soil from the fields when the temperature is 5°C. For varieties with poor cold resistance, sowing of shallow wheat fields with poor moisture content should cover the soil as soon as possible. During the winter period, the plastic film can be covered, which can increase the temperature and protect the earthworms, effectively prevent the freezing injury and slow growth, thereby increasing the tillering, the development of large scales, the formation of strong seedlings, and the improvement of the tillering into the ear. When the temperature is 3°C, the film is covered, and the lid is easy to grow early. After the lid is covered, the leaves are frozen. For late sowing, the film can be covered after sowing.