分蘖期控制灌溉对土温及水稻干物质积累等的影响

Effect of Control Irrigation on Soil Temperature and Dry Matter Accumulation of Rice During Tillering Stage

为了研究超级稻在双季稻区分蘖时期的最佳控水模式,2014年在华南农业大学农场以超级稻玉香油占为试材进行大田试验。在水稻分蘖数达到不同的2个阶段分别设置2个水分梯度处理,记录了控制灌溉期间土壤温度的变化,研究了其对干物质积累动态、LAI变化动态、光合特性以及成穗率和最终产量等的影响。结果表明：分蘖期控制灌溉（0~20 cm土层平均土壤相对含水率为（60±5）%能够扩大土壤5 cm深度日温差,减少拔节前干物质积累,提高拔节期净光合速率和生育后期叶面积指数,优化干物质积累动态,最终提高了W1和W2处理的成穗率与产量。因此,在玉香油占分蘖期控制0~20 cm土层平均土壤相对含水率为（60±5）%,能够达到节水高效栽培的目的。

To investigate the optimum mode of irrigation in double-harvest rice area in South China during tillering stage,super rice Yuxiangyouzhan was selected as experimental material; field experiment was conducted in SCAU farm in 2014. Two water gradient treatments were set respectively in two different tillering stages,soil temperatures were recorded during treatment periods,effect of control irrigation on dry matter accumulation,dynamic of LAI change,photosynthetic characteristics,panicle rate and yield were studied. Results showed that： control irrigation during tillering stage（ the average relative soil water content reach about（ 60 ± 5） % at 0- 20 cm soil layer）could enlarge soil diurnal temperature range in 5 cm soil layer,reduce dry matter accumulation before jointing stage,improve photosynthetic rate and LAI in late growth stage,matter accumulation dynamic was optimized thus W1 W2＇s panicle rate and yield were improved. Therefore,control 0- 20 cm soil layer＇ s average relative water content at（ 60 ± 5） % during tillering stage of Yuxiangyouzhan could attain the goal of water-saving and high-efficiency cultivation.