When will the northern vines be buried?
The most concerned issue for grape growers in the north is winter protection. As a perennial vine, the cold resistance of grape trees directly affects the yield in the coming year. In the extreme climate of minus 20℃, scientific soil burial cold prevention technology can effectively ensure the survival rate of plants. This article will systematically explain the timing of soil burial and the entire process of overwintering management. Critical temperature and regional differences for grape tree burial time selection According to observation data from China Academy of Agricultural Sciences, when the temperature continues to fall below-6 ℃, grape roots begin to suffer freezing damage. Early frost generally occurs in mid-November in northern regions, and actual operations require completion of soil burial 15 days in advance. Liaoning recommends that operations be carried out from November 1 to 10, while Heilongjiang should be completed before October 25. Soil state judgment standard The best operation period is when the surface soil is turned during the day and is frozen at night. A shovel can be inserted into the soil layer to test: the soil block can be formed but does not stick to the tool, that is, the ideal humidity state of "forming a ball when held and dispersing when it falls." The triple protection technical points of the northern grape overwintering protection system 1. Water management: Frozen water needs to penetrate into 80cm deep soil layer, and the amount per mu is about 60m³. Use ditch irrigation to prevent water from washing the roots. 2. Branch and vine treatment: Trim and retain 8-12 bud eyes, disinfect the cut with 5% copper sulfate solution, and keep the branches and vines naturally curved when bundling. 3. Layered soil burial: The first soil thickness was 15cm, the second time increased to 60cm, and the base width of the mound was expanded to 2 meters, forming a 30° slope. The new cold-proof material is applied on the basis of traditional corn stalks. It is recommended to use 3cm-thick PE foam insulation board, combined with geotextile coverage, which can increase the rhizosphere temperature by 4-6 ° C. Experimental data showed that this combination increased the survival rate of bud eyes to 98.7%. Spring nursing connection measures After the Qingming Festival, the temperature will be stabilized above 10℃, and the cold-proof soil will be removed twice. The top 1/3 of the soil layer was removed for the first time and completely removed after an interval of 7 days. Combined spraying of 0.3% urea +0.2% potassium dihydrogen phosphate solution can promote the germination of hidden buds.