不同秸秆覆盖量对旱地小麦生理生化特性的影响

Effect of straw mulching rates on physiological and biochemical characteristics of wheat in dryland

为了阐明秸秆覆盖对小麦生理生化特性的影响,筛选出适宜豫西旱地小麦高产栽培的秸秆覆盖量,以豫麦49-198为材料,采用大田试验,设置5个秸秆覆盖量水平(不覆盖为对照(Ⅰ)、2 000 kg·hm-2(Ⅱ)、4 000 kg·hm-2(Ⅲ)、6 000 kg·hm-2(Ⅳ)、8 000 kg·hm-2(Ⅴ)),研究了小麦抽穗期后旗叶SPAD值和光合速率,可溶性糖、脯氨酸、可溶性蛋白质、丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性等生理生化特性和产量特征。结果表明:小麦抽穗后,在一定秸秆覆盖量范围内随覆盖量的增加,各处理总体表现为小麦旗叶SPAD值升高,净光合速率增强,可溶性糖、脯氨酸和可溶性蛋白质含量升高,MDA含量降低,SOD、CAT和POD活性增强,小麦产量增加;且秸秆覆盖处理,除MDA含量减少外,其余各指标均较对照有所增加,但覆盖量超过一定水平后,各指标增幅(降幅)不明显。处理Ⅳ的各指标均优于其它覆盖处理并与对照有显著差异。综合分析可知,在豫西旱地生态条件下,6 000 kg·hm-2为最佳秸秆覆盖量。

To better understand the effects of straw mulching on physiological and biochemical characteristics of wheat and obtain optimal straw mulching rate for the best cultivation of wheat in dryland in the western Henan Province. The cultivar,Yumai 49-198 was used as test wheat crop with 5 straw mulching rates,0 kg·hm-2(Ⅰ),2 000 kg·hm-2(Ⅱ),4 000 kg·hm-2(Ⅲ),6 000 kg·hm-2(Ⅳ),8 000 kg·hm-2(Ⅴ). The influence of straw mulching rates on physiological and biochemical indexes in different stages after heading of Yumai 49-198 and the yield were studied.The results showed that increasing straw mulching rates below 6 000 kg·hm-2increased chlorophyll content,photosynthetic rates,contents of soluble sugar,proline,soluble protein,the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT) and wheat yield. It decreased malonaldehyde(MDA)content. Straw mulching rates above 6 000 kg·hm-2did not significantly impact these indexes. Consequently,straw mulching rate of 6 000 kg·hm-2was the most optimal rate in dryland of the western Henan.