不同作物的吸钾能力及其与根系参数的关系

THE RELATIONSHIP BETWEEN POTASSIUM ABSORPTION ABILITY AND ROOT PARAMETERS OF DIFFERENT CROPS

在温室盆栽条件下，研究了小麦和苕子在不同土壤（黑淤土、高砂土、白土）上的吸钾特性与钾肥肥效、作物根系参数变化间的关系。初步结果表明：小麦吸钾能力大于苕子，主要是前者利用土壤非交换性钾的能力较强。这两者根系的总活跃吸收表面积间的差异表现最为明显，并且与作物吸钾量、生物产量间呈显著正相关。此外，不同土壤上同种作物的根系生物产量、根系活力与作物吸钾量间也呈正相关。单位根重的阳离子交换量：苕子＞小麦，它受土壤供钾状况影响较小。不同供钾水平土壤上，钾肥肥效均以小麦优于苕子，钾肥利用率也以小麦较高。

Studies on the pot experiments with three different potassium supply soils indicated that wheat had stronger ability of utilizing soil nonexchangeable potassium and much higher utilization rate of potassium fertilizer than vetch. The significant differences of root physiological perameters were in the total and active absorption surface areas which were affected by soil potassium supply condition and hud markedly positive correlation with total uptake of soil potassium and shoot yield. There was also a significant correlation between the root activity, root weight and soil potassium uptake of the same crop. The cation exchange capacity of unit root weight of wheat was smaller than that of vetch, which wasn't strikingly varied in the different potassium supply soils.