Alfalfa likes warmth and should be planted on leeward and sunny slopes. It can be planted in areas with a semi-arid climate, annual precipitation of 250 to 800 millimeters, and a frost-free period of more than 100 days. It can withstand the bottom temperature of about -20°C, and the soil requirements are not strict. It is most suitable for neutral or slightly alkaline sandy loam (PH7-9), and does not like strong acid and strong alkali soil.
1. Soil preparation and fertilization: Alfalfa seeds are small and require good plowing and land preparation to make the soil compact and flat without large clods. Maintain proper moisture content in the soil. Fertilization should use 100 kg of organic fertilizer as base fertilizer and 50 kg of phosphate fertilizer to promote root nodule formation and enhance nitrogen fixation capacity.
Autumn sowing has good moisture content (July-early August), and weeds are less harmful. It can also be sown in early winter before the soil starts to freeze.
2. Seeding amount and sowing method: The seeding amount is related to the quality of the seeds. Generally, for seeds with a purity of 90% and a germination rate of more than 80%, the seed amount per mu is about 1.5 to 2 kg, and the sowing depth is 2 to 3 cm. It is most suitable for drill sowing with a row spacing of 30 cm, or hole sowing with a row spacing of 40 cm and a plant spacing of 30 cm, which is conducive to weeding management. It can also be sown and harrowed after sowing. If it is mixed with gramineous forages such as awnless brome, tall oxtail or elymus, one catty of alfalfa seeds per mu, 1.5 to 2 catties of gramineous grass seeds, interlaced at a ratio of 1:1 or 2:1 intercast.
3. Field management of alfalfa: it mainly fights against weeds. Due to the slow growth of young grass, one to two years after sowing, weeding should be done once or twice in time.
4. Cutting of alfalfa: it should be cut at the full flowering stage or when the plant reaches a certain height, although it has not bloomed and the new shoots from the root neck have grown to 6 cm long, the dry matter is 18%, Crude protein 4.7%, crude fat 0.8%, nitrogen-free extract 7.6%, ashes 1.8%. The last crop should not be too late, so that the regenerated grass can grow to a height of 10 to 15 centimeters, so that the roots can accumulate nutrients and survive the winter safely. Generally, the yield of green grass per mu is 5,000 to 6,000 jin, and the height can reach 8,000 to 12,000. About four catties of fresh grass make one catty of hay.
