【摘要】 研究蔬菜保护地18个长期定位施肥处理的土壤钾素Q/I曲线特性,结果表明,不同长期定位施肥蔬菜保护地土壤供钾容量(-?K0即QK)、供钾强度(AReK即IK)和缓冲能力PBCK差异明显,土壤基本理化性质的差异是其存在差异的根本原因;土壤CEC、速效钾、粘粒、有机质含量越高,土壤-?K0、AReK值越大,PBCK值越小.影响各处理Q/I曲线特性的主要原因各异,施有机肥的各处理主要因为CEC和速效钾含量高,从而-?K0和AReK值较高,PBCK值较低;施钾肥的各处理主要因为速效钾含量高,具有较高的-?K0和AReK值和较低的PBCK值;施高量氮肥的处理有较低的-?K0值和PBCK值和较高的AReK值,这或许与NH4+浓度大有关.更多还原

【Abstract】 Effects of 18 long-term located fertilizations on the quantity-intensity characteristics of potassium in sheltered vegetable field soil were investigated. The results showed that there were great differentiations between the quantity factor(-?K0)、intensity factor (AReK) and potential buffering capacity of K+ (PBCK) in different treatments, and the changes of basic physical-chemical properties contributed to this. When the contents of soil CEC, fast-available potassium, clay and organic matter were increased, the value of -?K0 and AReK increased but the value of PBCK decreased. The main reasons for changes in quantity-intensity characteristics of each treatment were different. The treatments using organic fertilizer presented a high value of -?K0, AReK but a low value of PBCK,primarily owing to the higher content CEC and fast-available potassium; the treatments using potassium also presented a high value of -?K0、AReK and a low value of PBCK, while the main reason may be the higher content of fast-available potassium; the treatments using great amount of urea produced a high value of AReK only but a low value of PBCK,-?K0,properly owing to the higher amount of NH4+.更多还原