苗期土壤水分控制对线辣椒生长和水分利用效率的影响

以我国北方普遍种植的经济作物线辣椒为研究对象,根据线辣椒的生理生长特点,通过盆栽试验,研究了苗期不同土壤水分下限对线辣椒长势、产量和WUE的影响。结果表明,在试验条件下,土壤水分下限控制在田间持水率(θF)的45%～60%时,线辣椒生长状况良好,50%θF时线辣椒的生物量、根冠比最大;各处理按线辣椒单株产量大小排序为:处理4>处理3>处理2>处理1>处理5>处理6;各处理按线辣椒全生育期WUE大小排序为:处理3>处理4>处理2>处理1>处理5>处理6。产量最高时的苗期土壤含水率为50%θF,WUE最高的苗期土壤含水率为55%θF,从而得出线辣椒获得较高产量所对应的苗期土壤水分下限为(50%～55%)θF。

Effect of Soil Moisture Deficit at Capsicum(Capsicum annuum L.) Seedling Stage on Its Growth and Water Use Efficiency

The lower limits of soil moisture are essential for efficient irrigation techniques in crop management.A pot experiment was conducted for capsicum to evaluate the effects of different soil moisture deficit(the lower limits being 70%,60%,55%,50%,45% and 40% of field capacity) during seedling period on the growth,fruit yield and water use efficiency(WUE) of the crop.The results showed that: ① the capsicum plants performed quiet well for the 60%,55%,50% and 45% treatments,but not in 70% and 40% treatments;② plant dry matter production was the greatest in the 50% treatment which also displayed the largest root / shoot ratio;③ fruit yield decreased with the lower limits of soil moisture changed from 50%,55%,60%,70%,45% to 40%;④ WUE decreased with the lower limits of soil moisture changed from 55%,50%,60%,70%,45% to 40%,which was similar to the case of fruit yield.We thus concluded that the optimal lower limit of soil moisture for capsicum during seedling stage was 45% to assure the plant growth as well as to maintain fruit yield.