分蘖期控制灌溉对土温及水稻干物质积累等的影响

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。

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

To investigate the optimum mode of irrigation in double-harvest rice area in South China during tille-ring 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 temper-atures 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 irriga-tion 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-effi-ciency cultivation.