Detailed Explanation of Key Techniques for Cultivating Yam in Shallow-Growth Grooves

Using shallow-growth grooves to cultivate yam allows the yam to grow along the direction of the groove; the resulting yam stems are straight, long, round and plump, and because the shallow soil layer has a large day-night temperature difference, the yam matures quickly, is easy to harvest and yields well. Here we introduce for everyone the shallow-growth groove yam cultivation techniques.

I. Shallow-Growth Groove Yam Cultivation Techniques

1. Land preparation: It is suitable for growing in sandy soil and loam with deep soil layers, loose texture and fertile soil, with the soil ranging from slightly acidic to slightly alkaline. Then plow deep and let the soil bleach in the sun; from late February to early March, make beds 30-40 cm high and 1.3-1.4 m wide, and dig parallel slanted small trenches 7 cm wide and 120 cm long at a plant spacing of 18-20 cm, with a slant of 15 degrees, the upper end 10-15 cm deep and the lower end 25-30 cm deep.

2. Placing the grooves: Place shallow-growth grooves suitable for yam growth into the trenches; backfill the upper 10-15 cm portion of the groove with soil, and fill the remaining space with enough loose filler. The loose filler can be silt, or decomposed sawdust, mushroom residue, sugarcane bagasse, medicinal dregs or rice husks, etc.; then add 200-300 kg of decomposed chicken manure or pigeon manure, 100 kg of bio-organic fertilizer and 25-50 kg of superphosphate per mu and mix well with the loose filler.

3. Placing the seed: Select tubers with a short neck that are thick and strong, unbranched and free of pests and diseases, and use the section of the upper end of the tuber that has a bud as the seed piece, then sprout it. Place the bud-bearing seed piece parallel to the shallow-growth groove with the bud facing up; keep only 1-2 strong young shoots per plant and thoroughly remove excess young shoots, then cover with soil 5-10 cm thick, taking care not to break the young shoots.

4. Management: Before the seedlings reach 30 cm in height, trellises must be set up, commonly in the form of a herringbone trellis or a four-corner trellis, with a trellis height of 1.5-1.7 cm and the trellis material inserted 20-30 cm deep into the soil. When the seed piece sprouts, pull out excess stems and vines, keeping only 1 thick main stem; if there are too many side branches, remove them appropriately. Before land preparation, apply 45-75 cubic meters of decomposed organic fertilizer, 350-400 kg of diammonium phosphate, 250-300 kg of urea and about 150 kg of potassium sulfate per hectare; during the vigorous growth period of stems, leaves and tubers, apply 1 topdressing, with about 400 kg of nitrogen, phosphorus and potassium compound fertilizer per hectare. When the seedlings are about 1 m tall, water thoroughly; when entering the peak period of branch and leaf growth, water once more, watering lightly and not flooding with large amounts of water; when entering the period of rapid tuber expansion, water more, and if the soil is dry, water thoroughly with a large amount of water.

II. When Is the Best Time to Plant Yam?

Generally, planting is required after the 5 cm soil temperature has steadily passed 9-10°C. In southern Sichuan and the Guangdong-Guangxi region, planting can be done in March; in the Sichuan region, planting can be done from late March to April; in North China, planting can be done in mid-to-late April; and in Northeast China, planting can be done in early May. Choose sunny or cloudy days for planting, avoid scorching sun exposure, and it is best to plant in the afternoon. From late October to November, when the stems and leaves have all withered, begin harvesting the tubers.