施氮水平对夏播花生氮素及干物质积累的影响

Effects of Nitrogen Fertilizer Rate on Nitrogen and Dry Matter Accumulation in Summer Peanut

基于黄河流域夏播花生种植区两个类型花生品种(豫花15和白沙1016)不同施氮水平进行田间试验,研究夏播花生氮素积累动态,及与花生生产力的关系。结果表明,各施氮水平下,氮素积累动态呈近"S"型曲线;施氮量在120kg/hm2以下,花生植株氮积累量、叶面积指数、叶面积指数持续期、干物质积累量和各生育时期叶片氮浓度均随着施氮量增加而增加,但当施氮量达到和超过120kg/hm2时均出现滞涨;每个施氮水平下,整个叶层平均氮浓度随着生育进程推进均呈下降趋势,但随着施氮量增加氮浓度下降速度趋缓。本研究用叶面积指数持续期拟合的动态曲线较好地区分了不同施氮水平间的差异,该曲线显示,在苗后10℃以上积温归一化值RGDD≤0.5时,夏播花生的叶面积指数持续期呈指数曲线增长;当RGDD>0.5时,呈线性增长。

Summer peanut nitrogen accumulation dynamics and its relationship with peanut pro- ductivity were studied through plot nitrogen fertilizer rate experiment with 2 summer peanut varieties （YH15 and BS1016） in the Yellow River Basin in China. The results showed： nitrogen accumulation of peanut was found as the ＂S＂ type curve. While nitrogen fertilizer application amount was less than 120 kg/ha, the peanut plant nitrogen accumulation, leaf area index, dry matter and the leaf nitrogen concentration increased with the increase of nitrogen fertilizer rate, but they showed stagflationary when the nitrogen rate reached over 120 kg/ha. At each level of nitrogen application, the leaf nitrogen concentration decreased with the increasing of the growth process, but decreased gradually with the increase of nitrogen application rate. The LAID dynamic curve could distinguish the peanut growth differences under different nitrogen fertilizer rate. The curves showed that the LAID complied with exponential curve when RGDD≤0.5 and linear growth when RGDD〉0.5.