Effects of irrigation amount and salinity on photosynthetic characteristics and yield of cotton under drip irrigation
In order to explore the response mechanism of photosynthetic characteristics and yield of cotton to irrigation salinity and irrigation amount under mulched drip irrigation.The field plot experiment was carried out with"Xinluzao 48"as the research object in 2023.Two irrigation amounts of 4 500 m3·hm-2(W1)and 3 600 m3·hm-2(W2)and three irrigation salinities of 1(S1),3 g·L-1(S2)and 5 g·L-1(S3)were set to analyze their effects on photosynthetic characteristics and yield of cotton.The results showed that under adequate irrigation,appropriate brackish water irrigation can increase leaf area index(LAI),chlorophyll content(SPAD),net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),light use efficiency(LUE)and stomatal limitation values(Ls),while reducing intercellular CO2 concentration(Ci).Inadequate irrigation or high salinity will increase Ci,decrease LAI,SPAD,Pn,Tr,Gs,LUE and Ls.Compared with S2W1 treatment,S2W2 treatment increased the leaf water use efficiency by 3.19%and 14.79%at seedling and flowering and boll stage.The seed cotton yield of S2W1(4 957 kg·hm-2)was significantly higher than that of S1W1(4 887 kg·hm-2),and S3W2(4 173 kg·hm-2)with increases of 1.43%and 18.79%.The results of path analysis showed that LAI,Pn and Ls at flowering and boll stage had the greatest direct contribution to yield,and Gs had the greatest indirect contribution to yield mainly through LAI,Pn LUE and Ls.The leaf area index and chlorophyll of cotton treated with S2W1 were the largest,which promoted the photosynthesis and light energy utilization rate of leaves to maintain the highest,ultimately increasing the yield of cotton.
cottonmulched drip irrigationmineralization of irrigation waterirrigation water amountphotosynthesis
万方数据
维普
