不同稻草还田方式对双季稻产量及其上部三叶特征的影响

于2010-2011年, 以双季早稻"陆两优996"和双季晚稻"五丰优T025"为材料, 研究了不同稻草还田方式对双季稻株型指标及产量的影响。结果表明, 在等养分条件下, 较单施化肥相比, 稻草全量还田能显著提高双季早稻的产量, 而双季晚稻产量稻草全量还田处理与稻草全部烧灰还田和单施化肥基本持平; 在不施化肥区, 无论是早稻还是晚稻, 稻草全量还田处理水稻产量均显著高于稻草烧灰还田和稻草不还田处理。稻草还田改善了双季稻上三叶株型特征, 早稻上三叶株型指标的优化效应高于晚稻, 但两者与水稻产量均呈显著相关(P<0.05); 当产量最高时, 早稻稻草还田处理上三叶株型指标趋近适宜值, 而晚稻规律不明显。稻草全量还田在一定范围内提高了双季稻上三叶的叶片质量, 其高效叶面积、高效叶面积率与产量呈抛物线关系, 比叶面积与产量呈显著或极显著线性负相关。以上结果表明, 双季稻上三叶叶系配置的改善是稻草还田增产的主要原因。

Effects of straw incorporation method on double cropping rice yield and the top-three leaf characteristics

Experiments were conducted on early rice "Luliangyou 996" and late rice "Wufengyou T025" during the double cropping seasons of 2010-2011 to study the effects of different methods of straw incorporation into soil on yield and top-three leaf characteristics of rice. The results showed that compared to non-straw incorporation, incorporating straw into soils significantly increased grain yield of early rice under equal NPK fertilization. However, straw incorporation was not significantly different from non-straw incorporation in terms of grain yield of late rice. Rice yield in straw-incorporated soils was significantly higher than non-straw incorporated soil under non-fertilization treatments in both early and late rice seasons. Straw incorporation ameliorated the characteristics of top-three leaves of double cropped rice, with higher optimization effect on early rice than on late rice. A significant relationship (P < 0.05) was noted between straw incorporation and grain yield. The index of the top-three leaves of early rice under non-straw incorporation was optimum when yield was maximum, which was not so obvious for late rice. Straw incorporation strengthened the quality of the top-three leaves of double cropped rice with a parabolic relationship between leaf area and leaf area rate of the top-three leaves with grain yield. A highly significant linear relationship was also noted between the specific leaf area and grain yield. The results suggested that rice yield increase under straw incorporation was mainly driven by the perfect structure of top-three leaves of double cropping rice.