晒田土壤含水量对水稻有效分蘖的影响

Effects of Soil Water Content After Field Drying on Rice Effective Tillers

为探究水稻有效分蘖与土壤含水量的关系,以杂交早稻‘淦鑫203’和晚稻‘五丰优T025’为材料分早晚季进行试验,以不晒田为对照,设计4个晒田处理（分蘖数达预计成穗数的70%连续晒田5天及10天、80%成穗数晒田5天及10天,分别记为W1、W2、W3和W4）,采用土壤水分自动记录仪监测土壤5、10、20 cm深的体积含水量,研究不同晒田处理条件下土壤含水量对水稻分蘖成穗的影响。结果表明：早稻分蘖末期W1、W3和W4晒田处理及晚稻W2和W3处理均能控制无效分蘖,提高成穗率。早稻晒田处理效果排序为：W4〉W1〉W3〉CK〉W2,晚稻为W2〉W3〉W1〉CK〉W4。单株有效分蘖数和成穗率与5、10、20 cm土壤体积含水量的关系可用二次曲线拟合;早、晚稻分蘖末期排水晒田至0～20 cm土壤体积含水量为47%～55%时,有效分蘖数和成穗率较高。

In order to investigate the relationship between effective tillers of rice and soil water content,experiments were carried out with early rice‘Ganxin 203＇and late rice‘Wufengyou T025＇, the treatmentwithout field drying was used as CK, four field drying treatments were conducted, which were field drying for 5days（W1） and 10 days（W1） when tillers came to 70% expected panicles, field drying for 5 days（W3） and 10days（W4） when tillers came to 80% expected panicles, soil volumetric water content in 5, 10 and 20 cm depthwas monitored by soil moisture recorder, the effect of soil water content under different field drying treatmentswas investigated. The results showed that treatment W1, W3, and W4 of early rice and W2 and W3 of late ricecould reduce ineffective tillers and increase earbearing tiller percentage in late tillering stage. The treatmenteffect of early rice was W4 〉W1〉 W3〉 CK〉 W2, and that of late rice was W2 〉W3 〉W1 〉CK〉 W4. Therelationship between effective tillers of per plant, earbearing tiller percentage and soil volumetric water contentin 5, 10 and 20 cm depth could be fitted by the quadratic curve. Effective tiller number and earbearing tillerpercentage reached the highest when 0-20 cm soil volumetric water content reached 47%-55% at late tilleringstage after field drainage and drying.