不同水氮磷钾耦合条件下玉米干物质与养分累积动态变化

Dynamic varieties of dry matter and nutrient accumulation in maize plants under different water and N、P、K supply condition

采用盆栽正交设计方案，研究不同水、氮、磷、钾耦合处理玉米干物质、养分N、P、K吸收累积的动态变化。结果表明，不同水、氮、磷、钾耦合条件下，玉米干物质、养分累积量随玉米生育期的延长而增加，累积趋势都呈“S”型曲线，可用指数方程Y=a exp（-b／t）拟合。玉米干物质累积速率和养分累积速率用Y=a exp（-b／t）求导可得，最大累积速率出现的时间可对指数方程Y=a exp（-b／t）求二阶导数得出。不同处理玉米干物质累积最大速率出现时间为玉米出苗后33．56～68．06d，N累积最大速率出现时间为出苗后14．73-64．19d，P累积最大速率出现时间为出苗后45．23～80．64d，K累积最大速率出现时问为出苗后18．80～53．91d。

The effects of different water and N,P,K supply on the dynamics of N, P and K uptake and accumulation were studied by pot experiment with the design of orthogonal. The results showed that the dry matter and nutrient accumulation were continuously increased with plant growth, and their accumulation in different plant-growing periods were shaped in S curves that could be described by the exponential regression equations. The momentary rate of the dry matter and nutrient uptake was obtained by the regression equations for the first derivatives. At the same time, the time for the maximum absorptive rate was obtained by the regression equa- tions for the second derivatives. The time for accumulation of maximum dry matter is 33.56- 68.06 d after the maize emergence, the times for accumulation of N, P, K are 14.73-64.19, 45.23-80.64, 18.80-53.91 d respectively.