灌排模式和施氮水平对水稻株高与茎蘖生长动态的影响

Effects of Irrigation and Drainage Modes and Nitrogen Levels on Rice Plant Height and Tiller Growth Dynamics

为探究灌排模式、施氮水平对水稻株高、茎蘖生长动态的影响,以稻田水位作为调控指标,通过测坑控水试验,采用Logistic曲线以及DMOR数学模型定量分析不同施氮水平下分蘖期先旱后涝(FHL)、拔节孕穗期先旱后涝(BHL)以及控制灌排(CID)3种处理对株高、茎蘖生长动态的影响。结果表明:灌排模式主要通过改变水稻株高、茎蘖的生长时间以及生长速率来影响株高、茎蘖生长,最大株高由大到小表现为CID处理、FHL处理、BHL处理,最大茎蘖数由大到小表现为CID处理、BHL处理、FHL处理。施氮主要是通过提高水稻株高、茎蘖的生长速率来促进株高、茎蘖生长;最大株高随着施氮量的增加而增加,CID和FHL两种处理下,最大株高由施氮150 kg/hm^2的98.9、97.8 cm增加到施氮300 kg/hm^2的102.4、101.2 cm,继续施氮没有显著提高;CID处理和BHL处理下,最大茎蘖数随着施氮量的增加而增加;FHL处理下,低氮处理和高氮处理的最大茎蘖数显著小于中氮处理。灌排模式与施氮水平的交互作用对株高、茎蘖数动态过程均有极显著影响,增施氮肥在一定程度上可以缓解因水分胁迫所引起的株高、茎蘖数的下降,但是高氮会加重水分胁迫,不利于株高、茎蘖的生长。

In order to study the effects of irrigation and drainage modes and nitrogen level on rice plant height and tiller growth dynamics,the water level in the paddy field was taken as the control index in the leaching-pond.Logistic curve and DMOR mathematical model were used to quantitatively analyze the effects of drought and flood alternating stress in tillering(FHL)and the drought and flood alternating stress in jointing-booting(BHL)stage and controlled irrigation and drainage treatment(CID)at different nitrogen levels on plant height and tiller dynamics.The results showed that the irrigation and drainage modes promoted the plant height and tillers mainly by changing the growth time and increasing growth rate of plant height and tillers.The maximum of plant height was shown as BHL,FHL and CID in descending order and the maximum number of tillers was shown as FHL,BHL and CID in descending order.Nitrogen fertilizer application promoted the plant height and tillers mainly by increasing growth rate of plant height and tillers.The maximum of plant height was increased with the increase of nitrogen application rate,from 98.9 cm and 97.8 cm with 150 kg/hm^2 input to 102.4 cm and 101.2 cm with 300 kg/hm^2 input,and no further significant increase was observed with more nitrogen input.Under the treatment of CID and BHL,maximum number of tillers was increased with the increase of nitrogen application rate.Under the treatment of FHL,the maximum tiller number under low nitrogen treatment and high nitrogen treatment was less than that under medium nitrogen treatment.The interaction between irrigation and drainage mode and nitrogen level had a very significant impact on the dynamic process of plant height and tillering.The decrease of plant height and tiller number caused by water stress could be alleviated by increasing nitrogen fertilizer to some extent.However,high nitrogen level can aggravate water stress,which was not conducive to the growth of plant height and tillers.