两种木质素磺酸盐对盐碱地玉米根际脱盐效应研究OA

This study investigated the differential effects of calcium lignosulfonate(Ca-LS)and potassium lignosulfonate(K-LS)on rhizosphere soil functioning,focusing on their ion-specific leaching capacity and salt stress mitigation efficacy in maize(Zea mays L.)grown in saline-alkali soils.Using Zea mays L.as the test crop,a soil column experiment was conducted with Ca-LS,K-LS,and calcium sulfate(CaSO4)as amendments,each at three application rates:0,0.117 and 0.175 g/kg soil,the application rate 0 g/kg was control(CK).The key maize growth indices(plant height,root dry weight,aboveground fresh weight),soil solution ion concentrations(Na+,Cl-),and salt ion distribution across soil layers were analyzed to elucidate the desalination and salt tolerance mechanisms of the two lignosulfonates.Significant differences were observed among the three amendments concerning their impact on maize growth and soil salinity.Regarding growth indicators:CaSO4 at 0.175 g/kg significantly increased maize shoot fresh weight.At the same application rate,KLS most significantly promoted plant height and root dry weight,increasing them by 8.28％and 32.48％,respectively,compared to the CK.In contrast,neither plant height nor root dry weight differed statistically between the Ca-LS treatment and the CK(P＞0.05).For soil salinity regulation:None of the amendments significantly altered rhizospheric soil pH(P＞0.05).However,all amendments promoted the downward migration of Na+and Cl-ions from the root zone to deeper soil layers.KLS at 0.175 g/kg exhibited the most pronounced leaching effect.K-LS and Ca-LS could serve as effective amendments for saline-alkaline soil reclamation by promoting the leaching of rhizospheric Na+and Cl-into deeper soil layers,thereby alleviating salt stress.Specifically,K-LS demonstrated a greater advantage in promoting soil Cl-ion leaching,while Ca-LS was more effective for soil sodium(Na+)ion leaching.Considering the combined effects on crop growth and soil desalination,the recommended application rate for both lignosulfonates was 0.175 g/kg soil.This application rate could create a favorable rhizospheric environment for crop growth in saline-alkaline soil.