夏玉米叶、鞘、茎和穗干物质积累的动力学研究

通过田间小区试验,对比研究施用氮肥和钾肥对夏玉米叶、鞘、茎和穗的积累速度、分期时长和积累量的影响。结果表明,夏玉米干物质累积进程采用logistic方程分段函数法模拟效果良好,相关系数R值达0.93以上。夏玉米所有器官中,果穗干物质积累量最高,占总生物量的66.1%~74.2%。N处理果穗干物质积累主要发生在积累中期,此时期积累的干物重占果穗干重的59.7%;K处理果穗干物质积累在3个时期分布均匀,前、中、后期干物质积累量分别占果穗干重的31.0%、30.3%和38.7%。N肥明显增强了营养器官(包括叶片、叶鞘、茎)的干物质积累速度,增大了积累量,但是到生育后期积累速度和积累量均下降。K肥的生物效应表现为维持植株营养器官在生育后期的积累活性,积累速度和积累量几乎不降低。

A Kinetics Study for Dry Matter Accumulation of Leaf, Sheath, Stem and Corncob of Summer Maize

A field experiment was carried out to compare the effect of N and K fertilizer application on dynamic change of dry matter accumulation for leaf, sheath, stem and corncob of summer maize. The treatments included:unfertilized control(CK), N fertilizer(N) and K fertilizer(K). The results showed that the simulated values by the way of the logistic equation and piecewise function were agreed well with the field data and the correlation coefficient value reached above 0.93. Corncob dry matter accumulation was the highest in all maize organs, which accounted for 66.1%-74.2% of the total biomass. Corncob growth was divided into 3 periods, including early period for slow accumulation, mid-period for rapid accumulation and later period for slow accumulation. Corncob dry matter accumulation of N treatment mainly occurred in the mid-period, which accounted for 59.7% of corncob dry weight. While for K treatment, the corncob dry matter accumulation of the early period, mid-period and later period accounted for 31.0%, 30.3% and 38.7% of corncob biomass respectively. N fertilization strengthened the speed and accumulation of leaf, sheath, stem, but the speed and accumulation decreased in the declining period. Different with N fertilizer, K fertilization could keep the accumulating activity of the nutritive organ in the latter period.