微咸水对滴灌棉花冠层光合特征及产量品质的影响

Saline Water: Effects on Canopy Photosynthetic Characteristics, Yield and Quality of Cotton Under Drip Irrigation

为探讨微咸水对新疆膜下滴灌棉花影响效果,利用排碱渠微咸水与河水混合方式,以河水为对照(CK),设置3 g/L和5 g/L两个微咸水矿化度,研究微咸水对滴灌棉花冠层光合特征及产量品质的影响。结果表明:灌溉初期微咸水对棉花影响不明显,至盛花期影响逐渐增强,与对照相比,微咸水滴灌使棉花LAI、MTA、Pn均降低,且5 g/L降幅大于3 g/L,而3 g/L蒸腾速率和气孔导度高于CK和5 g/L。微咸水滴灌使棉花产量降低,3 g/L下降不明显,5 g/L则显著下降,主要原因是单株铃数显著下降,而单铃重呈增加趋势,衣分无明显变化。微咸水对纤维长度和比强度无显著影响,但马克隆值显著增大。因此,低矿化度的微咸水在新疆棉花生产中可适当使用,是缓解棉花旱情实现稳产高产的重要途径。

To explore the effects of saline water on cotton under mulch drip irrigation in Xinjiang, the authorsused the mixing of saline water from alkali discharge canal with river water, set river water as the control（CK）and two treatments of saline water salinities of 3 g/L and 5 g/L, to study the effects of saline water dripirrigation on cotton canopy photosynthetic characteristics and cotton yield and quality. The results showed thatthe effects of saline water irrigation on cotton at early flowering stage was not obvious, and gradually increasedto the full-blossom stage; compared with the control, saline water drip irrigation decreased cotton LAI, MTA and Pn, and the decreasing effect of 5 g/L treatment was more than that of 3 g/L treatment, but the transpirationrate and stomatal conductance of 3 g/L treatment was higher than that of CK and 5 g/L. Saline water dripirrigation decreased cotton yield, 3 g/L treatment had less obvious effect than 5 g/L treatment, the main reasonwas the number of bolls per plant decreased significantly, while boll weight increased, and lint percentage hadno obvious change. Saline water had no significant effect on the fiber length and specific strength, but theMicronaire value increased significantly. Therefore, low saline water can be used in cotton production inXinjiang to alleviate the drought and achieve high and stable yield.