不同氮肥水平下紫苏生长的动态规律

采用田间试验定期采集紫苏样品,测定株高、叶面积、各器官干物质累量和分配情况,研究了不同氮肥水平下紫苏叶片生长和干物质积累与分配动态规律。结果表明,不同氮肥水平下紫苏株高、叶面积、干物质积累和分配动态相似,株高和干物质积累动态符合Logistic生长曲线方程,呈现“慢—快—慢”生长趋势,出苗后70-80 d出现株高增长高峰,高氮处理（N20,N15,N10）紫苏株高最大增长速度出现的时间较早、速度较快;出苗后80-100 d全株干物质积累速度最快,N5,N10处理,紫苏全株干物质积累量较高,最大干物质积累速度出现的时间较早,速度较快;出苗后100 d,紫苏叶面积大小和增长速度均达到最大值,N10和N5处理紫苏叶面积大小和增长速度明显高于其它处理;不同氮肥处理紫苏各器官干物质分配没有明显的区别。本试验条件下,紫苏施N量以75-150 kg·hm^-2较为适宜。

The Dynamic Growth Pattern of Perilla frutescens L.under Different N Applications

Field experiments were conducted to measure plant height, leaf area, dry matter accumulation of the organ of Perilla frutescens to study its dynamic growth pattern under different N applications. The result showed that the dynamic pattern of plant height, leaf area, dry matter accumulation and distribution was similar, exhibiting a ＂slow-fast-slow＂ pattern. Plant height and dry matter accumulation were all in line with the equation y=k/（1＋ae^-bx）. The maximum growth of plant height was at 70-80 days after emergence, and the biggest height growth rate was earlier and faster under N20 ,N15 ,N10 than that of other treatments. The dry matter accumulation rate was fastest at 80- 100 days after emergence, and the amount of dry matter accumulation was higher, earlier and faster under N5, N10 than those of other treatments. Dry matter distribution of different organs had no obvious difference among different treatments. The maximum amount and increasing rate of leaf area was on the 100th day after emergence. The amount of leaf area was obviously higher under N5 ,N10 than that of other treatments. The optimum N rate was 75-150 kg · hm^-2 under the condition of the present experiment.