Cultivation techniques of bitter buckwheat in autumn

(i) Selection of varieties. Tartary buckwheat varieties with many branches, concentrated seed setting, early seed setting, high seed setting rate, strong cold resistance and high yield were mainly selected. (2) Fine soil preparation. Soil preparation requires fine, tillage depth of about 20 cm, removal of previous crop residues and weeds, conducive to seeding and emergence, deep ploughing and fine harrowing, so that the land is flat, and pay attention to ditching drainage. (iii) sowing at the appropriate time. In the case of competing with other crops, sow as early as possible to avoid frost damage in the later stage. The planting area of buckwheat in our county should be sown before the beginning of autumn. The sowing depth depends on the soil type of the planting area, preferably 3~4cm. The sandy loam is slightly deeper, the clay loam is slightly shallower, and the covering soil thickness is consistent. (4) Reasonable close planting. Sowing density is determined according to soil fertility conditions, and the sowing rate is generally controlled at 5~7kg per mu. When sowing, the row spacing is 30~35cm and the hole spacing is about 20cm; when sowing in drill, the sowing width is 10~12cm and the row spacing is 30cm. (5) Scientific fertilization. Fertilizer application should follow the principle of "applying sufficient base fertilizer, applying top fertilizer early, applying phosphorus and potassium fertilizer appropriately". 750~1000 kg farm manure per mu, 15~30 kg calcium superphosphate as base fertilizer. 3~4 seedlings appear weak at true leaf stage, 2.5~ 5kg urea per mu is used to raise seedlings, and at initial flowering stage, 0.15~ 0.2kg potassium dihydrogen phosphate and 0.5~ 1kg urea can be sprayed on 60~ 75kg water for 2~3 times per mu to ensure sufficient nutrient supply at later stage, reduce bud drop and improve seed setting rate. (vi) Field management. (1)Thinning seedlings. When seedlings 3~4 true leaf stage, the seedlings of the plot and section too dense to thin, to weak and strong, to dense and thin. Ensure that there are about 200 seedlings per square meter. (2)Promote branching, control flourishing. Under the condition of higher water and fertilizer, the growth is vigorous. Spraying 100~200ppm paclobutrazol solution 40~50 kg/mu at the initial stage of bud emergence has the effects of reducing plant height, increasing branches, resisting falling and increasing yield, increasing yield by more than 15%. (3)insect control. Insect pests are mainly used in flowering stage, supplemented by insect pests in seedling stage. 2~3 times with kungfu, enemy kill and other pesticides. (7) Timely harvest. When 2/3 of the seeds of the whole plant are brown or silver-gray, it is suitable for harvest. In order to reduce seed loss, harvest should be carried out from early morning dew drying to 11:00 a.m., and gently cut and release. After cutting, sun drying and ripening for several days, threshing nearby to reduce loss.