地下滴灌条件下水钾耦合对紫花苜蓿的影响

Effect of Potassium Coupled with Water on Alfalfa under Drip Irrigation

为充分发挥地下滴灌技术的节水、节肥优势,进行了地下滴灌紫花苜蓿的水钾耦合试验。采用二因素完全随机区组设计,设4个钾肥水平(0、6g/m2、12g/m2、18g/m2)和W2(2d)、W3(3d)、W4(4d)3个灌水周期。结果表明:水、钾二因素对苜蓿株高、叶茎比及鲜草产量均有显著影响(P<0.05)。随着灌水周期的延长,苜蓿株高、叶茎比和鲜草产量均呈降低趋势,总体呈W2>W3>W4的关系。钾肥处理的株高、叶茎比和鲜草产量显著高于不施肥对照(P<0.05),随着钾肥施入量的增加,苜蓿株高、鲜草产量总体呈先增加后降低的趋势,叶茎比逐渐增高。苜蓿生长过程中最优地下滴灌灌水周期为2d,最优钾肥(K2O)施入量为12g/m2。

To take full advantage of subsurface drip irrigation technology in the water and fertilizer savings of alfalfa,experimental trials were carried out to study effect of water-potassium coupling on alfalfa under subsurface drip irrigation.In the experiment two factors completely randomized block design was applied,and alfalfa was grown under four potassium application levels and W2（2days）,W3（3 days）,W4（4 days）three irrigation levels making twelve combination treatments.The results showed that water and potassium supply had significant effect on the plant height,leaf-stem ratio and fresh forage yield of alfalfa（P 0.05）.The plant height,leaf-stem ratio and fresh forage yield decreased with the irrigation frequency, and the sequence was W2 treating W3 treating W4 treating in the irrigation condition.In addition, the plant height,leaf-stem ratio and fresh forage yield were significantly enhanced by the application of potassium（P〈0.05）;the plant height and fresh forage yield were increased first,then decreased with increasing application of potassium,while the leaf-stem ratio was gradually improved.Under this experimental conditions,the combination of irrigation every 2days and 12g/m2 potassium was the best treatment for the growth of alfalfa.