氮、磷、钾营养对冬小麦光合作用及水分利用的影响

在中国科学院封丘农业生态实验站长期肥料实验的基础上,选择氮磷(T1)、氮钾(T2)、磷钾(T3)和氮磷钾(T4)4个肥料处理,以不施肥为对照(CK),研究了长期施用氮、磷、钾肥对小麦抽穗期和灌浆期净光合速率(Pn)、蒸腾速率(Tr)和水分利用效率(WUE)日变化的影响.结果表明:小麦抽穗期和灌浆期T4处理的Pn日变化值显著高于CK,其他处理与CK未达到显著性差异,各处理Pn日积累量大小为T4＞T1＞T2＞T3＞CK;缺氮、缺磷和缺钾均降低了叶片Pn,影响大小依次为缺氮＞缺磷＞缺钾;小麦抽穗期和灌浆期Tr日变化曲线呈单峰型,处理间日变化值差异不显著;缺氮、缺磷和缺钾均降低了叶片WUE,抽穗期,T1、T4处理的WUE日变化值显著高于CK,而T3、T2与CK差异不显著,说明缺氮、缺磷对WUE的影响最大,灌浆期,T4处理的WUE日变化值显著高于CK;不同肥料处理仅改变了小麦光合日变化的幅度,而未改变其变化规律,氮、磷、钾复合施肥有效地提高了小麦的光合生产和水分利用效率.

Effects of N,P and K nutrition on photosynthesis and water use efficiency of winter wheat

This study was based upon a long-term fertilization experiment at the Fengqiu Agricultural Experiment Station of CAS.Four fertilization treatments including NP(T1),NK(T2),PK(T3) and NPK(T4),and non-fertilization(CK) were compared to investigate the effects of long-term application of N,P and K on the daily variations of net photosynthesis rate(Pn),transpiration rate(Tr) and water use efficiency(WUE) of wheat(Triticum aestivum) at its heading and filling stages.The results showed that the daily accumulative Pn at the two stages was in the order of T4>T1>T2>T3>CK,but statistically significant difference only occurred between T4 and CK.N,P or K deficiency reduced the Pn,with the order of N>P>K.The curves depicting the daily variations of Tr at both stages were all single-humped and similar in shape,and no significant differences in daily Tr variation were found among all treatments.N,P or K deficiency reduced leaf WUE.At heading stage,T1 and T4 had significantly higher daily accumulative WUE than CK,while the daily accumulative WUE in T1 and T4 was not significantly differed with CK,indicating that WUE was affected most strongly by N or P deficiency.At filling stage,the daily accumulative WUE in T4 was significantly higher than that in CK.Different fertilization treatments affected the range,but not the rhythm,of the daily photosynthetic variations of winter wheat.Our results suggested that applying N,P and K in combination could improve the Pn and WUE of wheat more effectively.