How do northern grapes spend the winter?
Winter and cold protection of northern grapes is an important part of cultivation and management. In a severe cold climate, soil burial operations not only protect plants from freezing damage, but also directly affect next year's yield. This paper will systematically analyze the technical points of buried soil cold prevention and discuss auxiliary protective measures to provide a complete solution for grapes to safely overwinter. Technical points for soil burial cold prevention Scientific irrigation and freezing water sealing is the first barrier for overwintering protection, and watering needs to be completed 10 days before soil burial. Each grape should ensure a watering amount of 30-50 liters to ensure that the soil moisture content reaches more than 70%. Sandy soil needs to be watered twice, with an interval of 3 days, to prevent rapid water loss. Clayey soil needs to be combined with intertillage to avoid hardening and affecting root respiration. Initial burial stage of phased soil burial operation: When the temperature stabilizes at 2 ° C, bind the pruned main vines at an angle of 30° and cover them with 5 cm of fine sand. Using the "bow vine pressing method" can reduce branch damage and increase the survival rate of retaining bud eyes by 40%. After burying the soil, check the spacing between branches and branches and maintain a ventilation gap of more than 10cm.
Deep burial stage: When the temperature drops to-5℃, secondary soil covering is implemented, and corn stalks are used to form a composite insulation layer. The thickness of buried soil follows the rule of 1:1.5, that is, 1.5 cm of covered soil is increased for every 1℃ drop in temperature. The recommended total thickness is 80cm in Northeast China, and 60cm in North China. Auxiliary cold protection measures Physical protection plans can build wind barriers based on buried soil to reduce the risk of freezing damage. 1.5-meter-high corn stalk barriers were set up every 8 meters, and microclimate zones were formed in conjunction with plastic film coverage. Experimental data show that this combination can increase the rhizosphere temperature by 3-5℃. Chemical protection measures Spray 5% amino-oligosaccharide solution before burying in the soil to enhance the expression of cold resistance genes in plants. Combined with white coating agent to treat the main body (quicklime: stone-sulfur mixture: salt =10:1:0.5) can effectively prevent sunburn and freezing cracking. Special terrain treatment plan Slope vineyards adopt stepped soil burial method, with a height difference of 15cm for each level to form an insulation layer. Drainage ditches need to be excavated in advance for low-lying plots, with a depth of 40cm and gravel laying the bottom to prevent root rot caused by snow melting water.
Through scientific soil burial and comprehensive protection, the survival rate of northern grapes over winter can reach more than 98%. Growers should adjust buried soil parameters based on local extreme low temperature records, regularly check soil moisture, and cooperate with spring soil cleaning techniques to achieve dual guarantees of safe overwintering and high yield.