麦秸还田对隔茬冬小麦根系及叶片衰老的影响

Effects of Returning Straw into Field on Next Year Winter Wheat Root System Development and Leaf Senescence

对麦秸翻压还田后隔茬冬小麦根系活力、旗叶叶绿素含量、丙二醛(MDA)含量及光合速率等衰老指标进行了测定分析.结果显示,(1)小麦秸秆还田后可显著促进各时期根系的生长并显著提高小麦根系活力,且根系在30cm处土壤中的分布增加;(2)冬小麦生育后期叶片叶绿素以处理Ⅲ(6 000 kg/hm2)的降解速度(18%)最慢,旗叶光合速率在灌浆期和蜡熟期以处理Ⅲ为最高,旗叶丙二醛含量以处理Ⅲ最低,比对照(Ⅰ)低6.78 mmol·g-1FW,丙二醛含量与光合速率呈显著负相关.研究结果表明,适量秸秆还田对接茬玉米的产量影响不显著,但可显著延缓隔茬冬小麦的衰老并显著提高产量,在黄土高原有灌溉条件的地区以6 000 kg/hm2的小麦秸秆量还田较适宜.

The experiment was conducted to study the effects of returning wheat straw into field on the wheat root system development, the chlorophyll content of leaves （Chl）, the malondialdehyde content （MDA） and photosynthesis rate in the next year. The results showed that （1） with the treatment of returning straw into field,wheat root system＇s growth, distribution in the in-depth soil can remarkably be enhanced;（2）The chlorophyll content of winter wheat leaf was increased with the increase of the returning straw quantity. However,at the later filling period,the chlorophyll content in leaves went to drop and the descent rates were significantly different among the various treatments. The slowest chlorophyll content descent rate and the highest photosynthesis rate were all the same one with treatment Ⅲ ; （3）Among the malondialdehyde content in flag leaves, the one with treatment Ⅲ was also the lowest. The negative correlation between MDA and photosynthesis rate was confirmed. As the results,the best treatment should be returning 6 000 kg straw per hectare into the field.