不同钾钙水平对白三叶草和黑麦草产量与品质的影响

EFFECT OF POTASSIUM AND CALCIUM SUPPLY ON YIELD AND QUALITY OF WHITE CLOVER AND PERENNIAL RYEGRASS

运用溶液培养方法研究了不同钾、钙营养水平对白三叶草和多年生黑麦草产量和品质的影响及钾、钙含量间的相互关系。这两种牧草在完全无钾溶液中不能正常生长,溶液钾浓度从0.375～3.0mmol/L,多年生黑麦草干物质产量略有上升,而白三叶草产量没有显著变化,对粗蛋白质含量影响也不明显。表明外液钾浓度达0.375mmol/L就已满足两种牧草生理上的要求。完全无钙时,两种牧草干物质产量很低,白三叶草表现更明显,比0.4mmol·Ca/L处理的低30和以上,说明白三叶草对缺钙更敏感。白三叶草产量在钙浓度为1.0 mmol/L时最高,钙浓度0.4～2.5mmol/L,对多年生黑麦草产量和品质影响不明显。地上部钾含量与钾供应水平呈正相关,与外界钙浓度相关性很小;而钙含量与钾供应水平呈负相关,与钙供应水平呈正相关。

Effect of potassium and calcium supply on yield and quality ofwhite clover and perennial ryegrass was investigated using solution culture. Bothcrops could not grow for 7 weeks long in K free solution. The yield of peren-nial ryegrass slightly increased with increasing K in solution from 0.375~3.0mmol/L, the dry matter production of white clover showed no obvious variation,and the effect of K supply on crude protein content was also not significant. Theresults indicated that the physiological requirment of K by these plants could besatisfied as K concentration in solution reached 0.375 mmol/L. The dry matteryields were rather low when no Ca was supplied, and compared with peren-nial ryegrass, white clover was more sensitive to Ca deficiency. The maximumdry matter production of white clover was obtained in 1.0 mmol Ca/L treatment.The change of Ca concentrations from 0.4 to 2.5 mmol/L had no significant in-fluences on yield and quality of perennial ryegrass. Potassium contents in shootsof the two species were positively correlated with K supply levels and not corre-lated with Ca concentrations in media; Ca contents in shoots, however, werenegatively and positively correlated with K and Ca supply levels, respectively.