Spring sowing in Huaishan is the best.

Huaishan (Dioscorea) cultivation technology:

Soil preparation

Dioscorea should be rotated for 2 to 3 years. In addition to plowing after fertilization, land preparation mainly involves digging loose trenches for the tubers to extend downward. Generally, the trench depth is more than 1 meter, the trench width is 20 to 25 cm, and the trench spacing is 80 to 100 cm. Manual trenching is time-consuming and is usually carried out before winter. When backfilling soil after trenching, be careful not to disrupt the sequence of soil layers. Using a special trenching machine is highly effective and can be done one month before sowing.

Planting

Generally, it is required that the ground temperature within 5 cm reaches a stable temperature of 9 to 10°C before planting. Planting can be done in March in southern Sichuan and Guangdong and Guangxi, in late March to April in Sichuan, in mid-to-late April in North China, and in early May in Northeast China. The method of planting is to use a hoe to dig a trench of 8 to 10 cm, place the seed potatoes lengthwise in the trench, and spread them evenly based on the bud mouth. The sowing density is generally 37,500 to 45,000 plants/ha, with a plant spacing of 25 to 30 cm and a row spacing of 25 to 30 cm. It's the groove distance. Before sowing, dig a seeding trench with a depth of about 10 cm directly above the trench. Place the seed blocks flat in the trench along the ridge according to the distance between the plants. The upper ends of the seed blocks face the same direction. After arranging the seeds, cover them with soil and pat them flat.

Management

Pruning and trellising: Dioscorea is a climbing plant. Before the seedlings are 30 centimeters tall, they must be trellised, with a height of 1.5 to 1.7 meters and a depth of 20 to 30 centimeters in the soil. Often set up as a herringbone or a quadrangular frame. When the seed tuber germinates, one main stem can generally extend out, but sometimes more than two can extend out. Correspondingly, 2 to 3 tubers will be produced, competing with each other for nutrients, making each tuber thin and small, affecting high-quality production. After the seedlings emerge, excess stems and vines should be removed immediately, leaving only one strong main stem. Some varieties have too many side branches. In the middle and later stages, the lower side branches, as well as the tops of the main stem and side branches should be properly removed. A large number of residual seeds are formed, which affects the growth of tubers. Generally, the amount can be controlled at 1500 to 2250 kg/ha.

Fertilization: Dioscorea requires a large amount of fertilizer. For every 1,000 kilograms of tubers produced, approximately 4.32 kilograms of pure nitrogen, 1.07 kilograms of phosphorus pentoxide, and 5.38 kilograms of potassium oxide are needed. Dioscorea should avoid chlorine and potassium chloride, and emphasize heavy application of organic fertilizers. Generally, 45 to 75 cubic meters of decomposed organic fertilizer, 350 to 400 kilograms of diammonium phosphate, 250 to 300 kilograms of urea, and about 150 kilograms of potassium sulfate are required per hectare of high-yield field base fertilizer. Before land preparation, the field should be spread and plowed at 25 centimeters of soil. Entering the vigorous growth period of stems, leaves and tubers, it is necessary to apply fertilizer again. Apply about 400 kilograms of nitrogen, phosphorus and potassium compound fertilizer per hectare and water.

Irrigation: In the early stage, there is no need to water as long as the topsoil is less than 5 cm moist. Generally, water is poured when the seedlings are about 1 meter apart; about 20 days apart, when the branches and leaves are in the peak growth period, water is poured again. The first two water should be poured shallowly, and flood irrigation should be avoided. About one month after the second watering, the tubers will enter a period of rapid expansion. If the soil is dry, it must be watered thoroughly. In autumn, pay attention to drainage and waterlogging prevention.

Harvesting

Start harvesting tubers from late October to November, when the stems and leaves are all dry. Tuber storage mainly involves heat preservation and anti-freezing. The suitable temperature is 2 to 4°C and the relative humidity is 80 to 85%. Can be piled, buried or stored in a cellar, etc. In the warm southern my country and the Yangtze River Basin, it can be harvested and put on the market. The leftovers must be harvested when they are ripe.