油菜苗期性状与其稻茬免耕直播产量损失的关系

稻茬油菜免耕直播技术可减少用工，降低冬闲田面积，但其产量常低于翻耕栽培模式。为探讨免耕直播油菜产量制约因素，在盆栽试验条件下测定各品系苗期根冠比、抗旱性、耐渍性及氮肥利用率等生理指标，在大田试验条件下测定15个油菜品系免耕产量损失率，并比较苗期各生理指标与免耕产量损失率的关系。结果表明，(1)同一油菜品种成熟期性状表现、产量及其构成因素在不同栽培模式下的差异因品系而异；(2)与翻耕比，免耕栽培时地上部干重、经济系数或千粒重降幅小的品系产量损失率也小；(3)稻茬免耕直播油菜产量损失率与油菜苗期根冠比、抗旱性及耐渍性显著负相关，与苗期氮肥利用率显著正相关；(4)栽培管理上应选用苗期根冠比大，抗旱性、耐渍性强及苗期生长稳健的品种，抗旱防渍，平衡施肥可提高稻茬免耕直播油菜的生产效率。

Relationship between Seedling Traits and Yield Loss of Rapeseed Direct-Seeded in No-Tillage Rice Stubble Field

Technique of direct-seeding rape in no-tillage rice stubble field can decrease the labor and reduce the area of winter fallow fields,but its output is often less than the tillage cultivation model.In order to investigate the production constraints of direct-seeding rape in no-tillage field,we designed a pot experiment to determine physiological indices of all lines such as root-shoot ratio,drought resistance,waterlogging tolerance and agronomy nitrogen use efficiency at seedling stage,and designed a field t...