For high yields of Chinese yam, the key planting techniques must be mastered well

As people's living standards continue to rise, Chinese yam is becoming more and more popular, and consumption is rising rapidly. Zhang Peihai, a farmer from Daluochebu Village, Tangwu Town, Changle County, Shandong Province, seized this business opportunity and used science and technology to develop Chinese yam production, becoming a widely known Chinese yam grower. The pollution-free Chinese yam he grows is large and of high quality, and is sold far away to cities such as Beijing, Tianjin and Shanghai, as well as to Japan, South Korea and Southeast Asia. In 2009, his 4 mu of Chinese yam brought a net income of 10,000 yuan per mu; in 2010 his 5 mu of Chinese yam averaged 12,100 yuan per mu; in 2011 the area expanded to 6 mu, and judging from this year's output (2,200 kg per mu) and current sales (average price 7.6 yuan per kg), the income per mu still reached more than 10,000 yuan. His main experience:

1. Choose suitable plots and do a good job of deep plowing and soil preparation. Chinese yam is a tuber crop; its tubers enter the soil relatively deeply, it is drought-tolerant and afraid of waterlogging, and it likes deep, loose soil. Therefore, he chose sandy loam soil with high, dry terrain and good drainage for planting. Sandy loam has good looseness and air permeability, warms up quickly, and sprouts early, which is favorable for the elongation and expansion of the tubers. In view of the fact that Chinese yam is not tolerant of continuous cropping and that continuous cropping aggravates diseases, he adopted a method of rotating Chinese yam with gramineous crops once every 2 years, effectively reducing or avoiding the occurrence of diseases. Every year after autumn, before the soil freezes, he digs planting trenches at a row spacing of 70-80 cm, with a trench depth of 100 cm and a trench width of 25 cm, placing the excavated raw soil and mature soil separately at the edge of the trench. After one winter and spring, the soil is fully matured, and the pests and diseases in the soil are killed by freezing. All large sand and stones, bricks and tiles encountered while digging the trenches are picked out to avoid injuring the Chinese yam tubers. In early spring of the following year, together with the application of base fertilizer, the soil is backfilled into the trenches, first filling raw soil and then mature soil, and every 30 cm of backfill is pressed down with the foot to prevent the planting trench from collapsing. 2. Select good varieties and apply sufficient base fertilizer. Good varieties are the internal cause of high yield and good quality. He selected the Japanese Yamato long yam, which has strong adaptability, high yield potential and excellent quality, laying the foundation for high yield and good quality of Chinese yam. Chinese yam has a long growth period and a large fertilizer requirement. To obtain high yield and good quality, scientific fertilization must be carried out according to the fertilizer requirement ratio of nitrogen, phosphorus and potassium of 4:1:5 for Chinese yam. First, apply sufficient base fertilizer: apply 3,000 kg of thoroughly decomposed high-quality organic fertilizer per mu, mix it with 100 kg of Sakafu compound fertilizer, and apply it in the soil layer below 25 cm. Because Chinese yam is a potassium-loving and chlorine-avoiding crop, if chlorine-containing fertilizer is used, it will cause the yield and quality of the tubers to decline, and they will be difficult to store and transport. Therefore, he never uses chlorine-containing fertilizer when growing Chinese yam, and pays attention to increasing potassium fertilizer. After fertilization, irrigate once with a large amount of water along the trench, and after irrigation loosen the soil at the right time to preserve moisture and raise temperature, laying a good foundation for sowing and ensuring seedlings of Chinese yam. 3. Sow at the right time and cover with plastic film. Chinese yam likes warmth and is not tolerant of frost. If sown too early, the soil temperature is low and seed rot is likely to occur. However, the growth period of Chinese yam is as long as about 180 days, and sowing too late will reduce yield and quality. Sow when the soil temperature at 5 cm is stable at 14 degrees C, around mid-April, and no later than the end of April. One month before sowing, choose a sheltered, sunny outdoor spot for sprouting. Before sowing, sun the seeds for 3-5 days, then soak the seeds for 15 minutes with 500 times Guan Jin liquid, or 300 times 40% carbendazim suspension concentrate, then remove and dry them for later use. After such treatment, the seed tubers can not only be sterilized and disinfected, but also promote complete, uniform and strong seedlings. Open trenches for sowing, with a trench depth of 7-10 cm, and apply 2-3 kg of phoxim granules per mu along the trench, which can control pests such as mole crickets, white grubs, cutworms and wireworms. For plots where nematode disease occurs, broadcast along the trench avermectin granules, or Yishubao granules, or Miral granules, 5-10 kg per mu. Apply 5 kg of Sakafu fertilizer per mu as seed fertilizer. Mix the fertilizer, pesticide and soil evenly, then irrigate once with a small amount of water along the trench. After sowing and covering with soil, cover with plastic film 1.2 m wide. Plastic film mulching has the effect of increasing temperature and preserving moisture, promoting seedlings to emerge 4-6 days earlier, and increasing yield by 10%-20%. To prevent weed damage, after leveling the ground before covering with film, spray the ground once with 150 mL of Duncap per mu mixed with 50 kg of water, which can control gramineous and broadleaf weeds, with an effective period as long as 45-60 days. 4. Strengthen field management to promote high yield and good quality. 1. After emergence, promptly break the film to release the seedlings; when half of the seedlings emerge from the ground and the seedlings are 20 cm high, set up trellises. 2. Topdress and earth up at the right time. The stem and leaf growth of Chinese yam at the seedling stage is small, and when the base fertilizer is sufficient, topdressing is generally not needed. Around mid-June, it enters the vine-throwing and plant-developing stage and needs more fertilizer, so carry out the first topdressing with 30 kg of Sakafu per mu to promote stem and leaf growth. From late July to early September is the tuber expansion period and also the peak period of fertilizer demand. In mid-to-late July, topdress 30 kg of Sakafu and 10 kg of potassium sulfate per mu. In order to protect leaves and nourish roots and promote tuber growth, foliar topdressing after late August can increase yield by 15%. Use 20 mL of tuber expansion agent per mu, mix with 50 kg of water, and spray on the leaves once every 7-10 days for 2-3 consecutive sprays; or spray 0.3% monopotassium phosphate 2-3 times. Combined with soil topdressing, earth up 2-3 times; earthing up is beneficial both for drainage and for tuber growth. 3. Water and drain in time. Chinese yam is a drought-tolerant crop. In the early growth stage, even if it is dry, watering is generally not needed, so as to favor downward growth of the rhizome. But in the peak tuber expansion period, it needs more water, so keep the soil moist frequently and water in time when drought occurs, and never flood-irrigate. In case of rain and waterlogging, drain the accumulated water early to prevent trench collapse and waterlogging-induced diseases that affect tuber growth. 4. Pay attention to pest and disease control. When Chinese yam enters the middle growth stage, it is in the high-temperature and rainy season, and field humidity is high, making it very easy for diseases such as anthracnose, brown spot, brown rot and viral disease to occur. Spray with 1,500 times Amistar plus 600 times copper hydroxide solution once every 10-15 days for 2-3 consecutive sprays, with good disease control effect. Viral disease is very likely to occur after heavy rain. The key to controlling viral disease is timely control of pests such as whiteflies and mites. 5. Remove Chinese yam beans early. During growth, Chinese yam beans consume a large amount of nutrients in the plant, seriously affecting tuber expansion. According to experiments, timely removal of Chinese yam beans can increase tuber yield by 15%-20%.