Abstract: The objective of this study was to find optimum ratio of base fertilizer for alfalfa (Medicago sativa L.) cultivation in sandy soil through evaluating the effects of different fertilizer types (Urea,DAP or MESZ,Red or Crystal potassium) and ratios (NPK ratio 12-17-18,10-20-24,no fertilizer-CK,only nitrogen-TN) on alfalfa productivity and quality. The results showed that 10-20-24 N-P-K ratio (applying crystal potassium) had the greatest single-plant root biomass. The dry weight of root was 161.16% and 77.93% greater than CK. Different fertilizer types and ratios ranged 832.95-1663.5 kg·hm^-2 for dry weight,respectively. However,10-20-24 N-P-K ratio (applying crystal potassium) had the greatest biomass in the next year. The dry weight of biomass was and 29.61% greater than CK. Crude protein had no significant difference among fertilizer treatments,but they all were slightly greater than CK. NDF and ADF were the lowest at TN treatment,were 37.02% and 24.20%,respectively. The results indicated that the optimum ratio of base fertilizer for alfalfa cultivation in sandy soil was 10-20-24 NPK with crystal potassium.

Key words: Alfalfa, Fertilizer type, Fertilizer ratio, Productivity, Quality

摘要： 本研究评估了不同基肥类型（尿素、磷酸二铵或美可辛、红钾或晶体钾肥）及配比（NPK配比12-17-18，10-20-24，不施肥CK和仅施N肥TN）对沙地土壤种植紫花苜蓿（Medicago sativa L.）的生长状况、生产力和品质的影响，旨在探索苜蓿沙地栽培的最佳基肥配方。结果表明14和15年单株根系干重在NPK配比为10-20-24且用晶体钾时表现最好，分别较CK显著增高161.16%和77.93%。不同的施肥类型及配比之间的产量干重变化在832.95~1 663.5 kg·hm^-2。次年生物量在NPK配比10-20-24且用晶体钾时表现最好，干产重较CK显著增高29.61%。相对CK，基肥能提高苜蓿中的粗蛋白含量，但在NPK的各配比处理间，粗蛋白含量无显著性差异。NDF和ADF在TN处理中最低为37.02%和24.20%。试验结果表明在沙地种植苜蓿较好的基肥施肥配比是NPK配比为10-20-24且钾肥最好选用可溶性更高的晶体钾。

关键词: 紫花苜蓿, 肥料类型, 施肥配比, 生产力, 品质