玉米秸秆还田与不同耕作方式下影响小麦出苗的因素

在华北平原小麦-玉米一年两熟条件下，玉米秸秆还田后小麦出苗率下降的原因可归纳为播种过浅、播种过深、秸秆或根茬物理阻碍、种子霉烂及土壤水分不足或干湿不均等5方面。影响出苗的关键因素在传统翻耕方式下（对照）依次是土壤水分不足、播种过浅、根茬阻碍；在秸秆粉碎还田后翻耕播种方式下为土壤水分不足、秸秆阻碍、播种过浅；在秸秆粉碎还田旋耕播种方式下为秸秆阻碍、土壤水分不足、播种过浅；在秸秆粉碎还田直播方式下为秸秆阻碍、播种过深、种子霉烂、播种过浅、土壤水分不足；在秸秆立秆直播方式下为秸秆阻碍、种子霉烂、播种过浅、土壤水分不足、播种过深。在后两2种种植方式下秸秆还田量与小麦出苗率可分别用y =402.67x^－0.7192和 y =509.4x^－1.0597表示。

Factors Affecting Seeding Emergence in Winter Wheat under Different Tillage Patterns with Maize Stalk Mulching Returned to the Field

The present study was to make clear the reasons affecting the emergence of winter wheat seedling in maize stalk mulching fields in North China Plain.The results indicated that the wheat seedling rates under all treatments of stalk return field declined compared with the traditional tillage pattern(ploughed before sowing,but no stalk mulching).The main five reasons are sorted as sowing too shallow,sowing to deep,physical obstacles by maize stalks,seed moldiness and deficiency or unevenness of soil water,and their priority orders in different tillage patterns were different.The relationships between weight of maize stalk return field(y) and number of wheat seedling(x) could be simulated by power functions y= 402.67x~(-0.7192)(mulched with whole stalks and un-ploughed and y= 509.4x~(-1.0597)(mulched with crushed stalks and un-ploughed).