| 摘要: |
| 结合田间试验与文献资料，分析了旱地秸秆覆盖条件下小麦收获指数降低的原因。结果表明，虽然大多数资料显示秸秆覆盖能够增加小麦产量，但是覆盖较常规耕作小麦收获指数下降最高达20%，这个现象不容忽视。其原因可能是：(1）小麦生育前期旺长消耗大量土壤水分，造成小麦后期严重的水分胁迫，影响籽粒灌浆。(2）小麦后期水分
胁迫可能引起冠层温度升高，导致热胁迫对籽粒灌浆不利；(3）旱地小麦氮肥播前一次施用方式有可能引起小麦后期氮营养不足，加速叶片衰老，影响花后光合产物形成，也不利于籽粒灌浆。 |
| 关键词: 小麦 收获指数 秸秆覆盖 氮素 冠层温度 |
| DOI： |
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| 基金项目:国家自然科学基金(31170411)；公益性行业科研专项（201103003）；农业科研杰出人才及其创新团队培养计划 |
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| Analysis of the causes of wheat harvest index reduction under straw mulching on dryland |
| ZHANG Shu-lan1, LIU Jun-mei1, LI Qing-hui2, FENG Yong-tao3, YANG Xue-yun1, CHANG Yan-li1 |
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| Abstract: |
| Based on field experiments and published data, this paper analysed the causes of wheat harvest index reduction under straw mulching in comparison with conventional management on dryland. Generally, many studies showed that straw mulching increased wheat yield.However, the harvest index decreased by 20% for straw mulching as compared with the conventional management. This decrease in harvest index were probably related to: (1) overuse of soil water before anthesis, which resulted in severe water stress during grain filling stage; (2) higher canopy temperature during grain filling stage; (3) leaf senescence and decreased leaf assimialation owing to the only once application of nitrogen fertilizer as basal. However, more work is needed to elucidate the mechanism underlying this reduction in harvest index. |
| Key words: wheat harvest index straw mulching nitroegn management canopy temperature |
