耕作方式及沉浆时间对机插晚稻生物学特性的影响

Effects of Tillage Methods and Mud Sinking Time on Biological Characteristics of Machine-Transplanted Late Rice

洞庭湖平原区是湖南重要的粮食主产区,针对该区域水稻机插农机农艺融合低的关键问题,设置了轻型旋耕机+耕作后沉实1d机插晚稻(T1-S1)、轻型旋耕机+耕作后沉实2d机插晚稻(T1-S2)、重型旋耕机+耕作后沉实1d机插晚稻(T2-S1)和重型旋耕机+耕作后沉实2d机插晚稻(T2-S2)4个处理,开展了不同耕作方式与沉浆时间对机插晚稻生物学特性的影响研究。结果表明:沉浆是减少漏兜及促进机插晚稻返青发苗的重要农艺措施,沉浆2d的平均漏兜率较沉浆1d降低45.7%,返青期缩短2d,而不同旋耕机型间无显著差异。耕作方式与沉浆互作对机插晚稻的前期及后期干物质积累的影响达显著(P<0.05)差异,T2-S2对机插晚稻后期干物质积累的贡献最大,较T1-S1、T1-S2、T2-S1分别增加22.6%、9.1%和21.9%。同时,T2-S2的叶面积,净光合速率,作物生长率及生育后期的净同化率均最大,达显著水平。因此,洞庭湖平原区的旋耕机型与沉浆时间的最佳组合为T2-S2。

Dongting Lake Plain is an important grain-producing area in Hunan Province.This study is aimed at the key problem of integration of agricultural machinery and agronomic in this region.There were four treatments including light rotary tiller and mud sinking after farming for 1 day(T1-S1),light rotary tiller and mud sinking after farming for 2 day(T1-S2),heavy rotary tiller and mud sinking after farming for 1 day(T2-S1)and heavy rotary tiller and mud sinking after farming for 2 day(T2-S2).Effects of tillage methods and mud sinking time on biological characteristics of machine-transplanted late rice were studied.The results showed that the mud sinking was an important agronomic measure to reduce the leakage rate of seedlings of late rice and promote the seedlings into green.The average leakage rate of mud sinking for 2 days was 45.7%lower than that of mud sinking for 1 day,and the turn-greening period was shortened by 2 days,however,there was no significant difference between the different rotary tiller types.The interaction effects of tillage types and mud sinking period on the dry matter accumulation in the early stage and late stages of late rice were significantly different(P<0.05).T2-S2 contributed the most to the dry matter accumulation in the late growth stage,increased by 22.6%,9.1%,and 21.9%respectively compared with T1-S1,T1-S2 and T2-S1.Simultaneously,the leaf area index,net photosynthetic rate,crop growth rate and net assimilation rate of T2-S2 were the highest,which reached a significant level among these treatments.Therefore,the best combination of rotary tiller type and mud sinking period in the Dongting Lake plain area is T2-S2.