When the tuber of Chinese yam grows deep under the soil layer, it should be turned deeply or ditched locally. In rotation, the furrow is dug according to the distance of 1 meter, with the width of 25 cm and the depth of 0.5- 1 meter, which varies with varieties. Intercropping is ditching according to 2-3 meters. It is best to plow the ditch soil before winter, and turn the soil into the ditch in early spring with the thawing of the soil. Finally, make a border according to the width of 1 meter for planting.

Generally, the sowing method adopts single row drilling, and a deep ditch of 10 cm is opened in the center of the border, and then the yam seeds or segments are placed in the ditch according to the plant spacing of 15-20 cm, and covered with 8- 10 cm. It starts from planting before the final frost in early spring and ends in first frost in late autumn and early winter.

Field management of yam

(1) Sparse seedlings

In case of cutting, the weak seedlings should be thinned as early as possible, and 1~2 strong ones should be reserved. The lateral branches at the base of the main stem hinder ventilation and light transmission and should be removed. During the formation of a large number of Reiyoshi, in order to avoid excessive consumption of nutrients, a part can be removed as early as possible.

(2) Fertilization

Basic manure can be applied after sowing and before scaffold, combined with available nitrogen fertilizer. Top dressing 1 2 times at the time of tree emergence to ensure the need of tree emergence. The stems, leaves and tubers begin to grow vigorously, and the compound fertilizer of nitrogen, phosphorus and potassium should be applied again.

(3) intertillage weeding

Combined with topdressing and watering, the intertillage should be shallow, and the weeds near the plants should be pulled out by hand to avoid damaging the roots.

4. Water

During the vigorous growth period of tubers, keep the soil moist. Yam is a drought-tolerant crop, but it should be watered properly for high yield. Generally, before and after 1 topdressing, if the soil turns white after a long drought, it should be lightly watered 1-2 times until the surface of the soil is wet. Later, at the turn of summer and autumn, if the dry and hot weather lasts for more than 1 week, cold water should be poured in the morning to fight drought; Yam is more afraid of waterlogging, so it is necessary to clear the ditch and drain water in time in rainy season to achieve no water accumulation in the field.