1, alfalfa sowing period is generally divided into spring, summer and fall sowing. The determination of the sowing period depends mainly on the temperature, moisture, the degree of weed damage, the purpose of utilization, existing conditions and so on. Among many factors, moisture is the decisive condition, and spring, summer and fall sowing can be used where there are irrigation conditions. North China generally plants from late May to early July. The first crop of alfalfa generally requires a 50-day growing period, the second crop requires a 35-day growing period, the third crop requires a 35-day growing period, and each crop can generally go up and down for 5 days, and the last crop is generally left with a 20-30 day growing period after harvest. After the return of the average daily temperature reaches 5 ℃ can grow.

2, early fall sowing, about 25 days after the start of harvest, can be harvested 4 times, mu yield of about 1000 kg. Late fall sowing, harvesting only 3 times, mu yield of about 600 to 700 kg. Early spring sowing, harvesting 3 times, mu yield of about 500 kg. Late spring sowing, harvesting in early July to late July, harvesting 2 times, mu yield is about 400 kg.