How are yams grown?

Chinese yam can be used as a vegetable or medicine. it grows in the forests of hillsides, valleys, streams, roadsides or weeds at an altitude of 1500 meters. So, how to grow yam?

1. Land preparation

Yam should be rotated for 2-3 years. In addition to ploughing and ploughing after fertilization, the main purpose of soil preparation is to dig loose ditches for tubers to extend downward, with a general depth of more than 1 meter, a width of 20-25 cm, and a spacing of 80-100 cm. Manual ditching is more time-consuming and is generally carried out before winter. When backfilling the soil after trenching, be careful not to disturb the order of the soil layer. Using a special trenching machine is highly effective and can be carried out one month before sowing.

2. Planting

It is generally required that the ground temperature of 5 cm can be planted after stable passage of 9-10 ℃. It can be planted in southern Sichuan and Guangzhou in March, in Sichuan from late March to April, in North China in mid-late April, and in Northeast China in early May. The planting method is to use a hoe to open a ditch of 8-10 cm, put the seed potato longitudinally in the ditch and spread it evenly according to the bud mouth. The sowing density is generally 3.75-45000 plants / ha, the plant spacing is 25-30 cm, and the row spacing is the furrow spacing. Before sowing, directly above the opened ditch, dig the sowing ditch with a depth of about 10 cm, put the seed block in the ditch along the ridge according to the plant distance, and the upper end of the seed block faces in the same direction. After arranging the seeds, cover the soil and beat flat.

3. Pruning and framing

Chinese yam is a climbing plant, before the seedling height of 30 cm, must build a frame, the frame height is 1.5-1.7 cm, and the frame wood is 20-30 cm deep. It is often built into a herringbone frame or a quadrangle frame. When the seed tuber germinates, it can generally extend one main stem, but sometimes it can extend more than 2, correspondingly, it will produce 2-3 tubers, competing for nutrients with each other, so that each tuber is thin and small, affecting high-quality production. Immediately after emergence, pull out the excess stem, leaving only one sturdy main stem. Some varieties have too many lateral branches, so it is necessary to properly remove the lower lateral branches, as well as the tips of the main stem and lateral branches in the middle and later stages. The formation of a large number of residual seeds affects the growth of tubers, which can be controlled in the range of 1500-2250 kg / ha.

4. Fertilization

Chinese yam needs a large amount of fertilizer, for every 1000 kg tuber, it needs to absorb 4.32kg of pure nitrogen, 1.07kg of phosphorus pentoxide and 5.38kg of potassium oxide. Chinese yam avoid chlorine, should not use potassium chloride, emphasize the re-application of organic fertilizer. General high-yield field base fertilizer per hectare need to apply 45-75 cubic meters of mature organic fertilizer, diammonium phosphate 350-400 kg, urea 250-300 kg, potassium sulfate about 150 kg, before soil preparation, sprinkled in the field, ploughed in about 25 cm soil layer. To enter the vigorous growth period of stems, leaves and tubers, it is necessary to re-fertilize for 1 time. About 400 kg of nitrogen, phosphorus and potassium compound fertilizer is applied and watered per hectare.

5. Irrigation

In the early stage, as long as the topsoil is less than 5 cm wet, there is no need to water. Generally in the seedling about 1 meter of water; every 20 days or so, into the peak period of branch and leaf growth, and then irrigate the second water, the first two times of shallow water, do not flood irrigation. About one month after the second water, the tuber entered the period of rapid expansion, and the soil should be watered thoroughly if the soil was dry. In autumn, pay attention to drainage and waterlogging.

6. Harvest

From late October to November, when all the stems and leaves withered, the tubers began to be harvested. The storage of tubers is mainly heat preservation and anti-freezing, with a suitable temperature of 2-4 ℃ and a relative humidity of 80-85%. Can be stacked, buried or cellar and so on. In the warm south of China and the Yangtze River basin, it can be listed on demand. Leftovers must mature and harvest.