How to select, prepare and fertilize the soil for planting yam?

How to select, prepare and fertilize the soil for planting yam? To grow Chinese yam, the soil should be strictly selected. In order to make Chinese yam high quality and high yield, it is necessary to choose soil or sandy loam fields with loose soil, high dryness, deep and fertile soil, convenient irrigation and drainage, and continuous cropping of Chinese yam. Continuous cropping is easy to cause soil nutrient imbalance and serious disease, and the rotation of yam should be carried out for more than 3 years. The cultivation of Chinese yam needs to be deeply ploughed and frozen before winter to make the soil loose. Tillage depth, flat blocks and cylinders, can be ploughed 30 cm deep, after ploughing, press 60-80 cm to make flat or high beds; long column species trench at a distance of 1 meter. The ditch is 60-100 cm deep and makes a flat bed after backfilling the ditch soil. Combined with the application of fully mature high-quality ring fertilizer more than 5000 kg per mu, and fully mixed with the soil, the main absorbing roots of Chinese yam grew horizontally and distributed evenly in the surface soil. Because the main absorbing root of Chinese yam grows horizontally, it is promulgated in the surface soil, and the fertilizer should be applied in the topsoil layer to facilitate absorption. Yam can sometimes be intercropped with other crops, and when intercropping, the distance of Chinese yam trenching depends on the width of the border of the crops and the height of the yam support.