Influence of nitrogen, phosphorus, potassium and sulphur fertilizer on alfalfa's yield and quality

In this article the experiment was carried out to adopt 4 factors (nitrogen, phosphorus, potassium and sulphur) and 3 levels with alfalfa fertilizer. The results indicated that fertilizer could increase the yield of alfalfa obviously. When urea 225 kg/hm~2, calcium superphosphate 262.5 kg/hm~2, potassium carbonate 675 kg/hm~2,and sulphur powder 75 kg/hm~2 were applied, the high yield was obtained respectively as follows:14 550,14 550, 13 678.5, 12 789 kg/hm~2. They were higher than the control respectively as follows:28.3%, 31.1%, 20.6%, and 13.7%. The fertilizer could increase the protein content of alfalfa, the potassium carbonate produced the best effect. When the first crop was at 225 kg/hm~2, the protein was (19.4%,)higher than the control 27.9%;When the second crop was at 450 kg/hm~2, the protein content was 20.1%, higher than the control 12.5%. The proper amount of nitrogen, phosphorus and potassium could promote alfalfa nutrient absorption. Sulphur powder has no remarkable effect on soil nutrition. Urea, calcium superphosphate and sulphur powder all could increase economic efficiency of alfalfa planting respectively:1476.9 yuan/hm~2, 1439.1 yuan/hm~2 and 750.3 yuan/hm~2.