施磷对紫花苜蓿光合特性以及生长的影响

盆栽条件下不同施磷水平对苜蓿光合特性及其产量和品质的影响研究表明，在苜蓿充分供应氮、钾等其它营养的基础上，适量施用磷肥能显著增加苜蓿叶片的叶绿素含量，提高其光合作用，从而促进苜蓿植株生长，增加苜蓿产量和品质。本试验条件下P4处理的紫花苜蓿两次收割的植株平均高度与不施磷比较，增加了3．54cm、侧枝数增加3．78个／株、全年产草量增加25％；苜蓿粗蛋白含量年平均比对照增加了4．87％；粗纤维含量年平均比对照降低了5．85％。达到最佳经济产量的施磷（P2O5）量为106mg／kg.

Effect of phosphorus levels on photosynthesis and herbage yield and quality of alfalfa

Effect of application of phosphorus fertilizers at different levels on photosynthesis and herbage yield and quality of alfalfa was studied.The results indicated that plants chlorophyll and photosynthesis rate were significantly increased.And then plant height and side branches of alfalfa were significantly higher in treatments with P application,compared with that in CK treatment.Plants height of alfalfa was increased by 3.54 cm and number of side branches increased by 3.78 per plant when fertilization P2O5 was 108 mg/kg.Herbage yield of alfalfa increased 25% all the year.There was significantly increased in content of crude protein,and significantly decreased crude fiber by P application properly.However,compared to the treatment without P application,crude protein was obviously increased 4.87% and crude fiber was obviously decreased 5.85% by applicating P2O5 108 mg/kg.The optimum P application rates based on benefit and yield was 231 kg/hm2(106 mg/kg) under this experimental condition.