氮、磷、钾配合施肥对紫花苜蓿产草量的影响

配合施肥是充分发挥紫花苜蓿（Medicago sativa）植株生长潜能、提高其饲草产量的有效手段，为探索山东农区紫花苜蓿栽培的最佳施肥组合，在山东省齐河县畜牧科技示范园，采用三因子三水平正交试验设计，研究氮、磷、钾不同水平组合对紫花苜蓿饲草产量的影响。结果表明，氮肥和钾肥对紫花苜蓿饲草产量影响不显著（P>0.05），磷肥能显著提高紫花苜蓿饲草产量（P<0.05）。互作效应分析显示，氮肥和磷肥的互作效应对第1茬草、第2茬草和总产草量的影响显著，与低水平的氮肥配施，磷肥增产的效果明显。从总产草量看，在试验条件下，N、P2O5和K2O施用量为60、90和100 kg·hm-2的组合获得的饲草产量最高，是试验点最佳的施肥组合。

Effects of fertilizer combinations of nitrogen, phosphorus and potassium on the forage yield of Medicago sativa

In order to provide the scientific basis for alfalfa fertilization, a field experiment was conducted to investigate the forage yield of alfalfa under different fertilizer combinations of nitrogen, phosphorus and potassium in Qihe, Shandong province. Orthogonal experiment design was used with 2 replicates. The results showed that there was no significant effect of nitrogen and potassium fertilizer on forage yield of alfalfa, however, phosphorus fertilizer significantly increased the alfalfa forage yield. The interactive effects between phosphorus and nitrogen on forage yield under the first cut and second cut were significant, and phosphorus fertilizer mixed with low level of nitrogen fertilizer effectively improved alfalfa forage yield. According to the total forage yield of alfalfa, the proper combination of nitrogen, phosphorus and potassium applied for alfalfa in experiment field was 60 kg·ha-1 N， 90 kg·ha-1 P2O5 and 100 kg·ha-1 K2O.