生物炭与有机肥配施对盐碱土改良和向日葵产量的影响

Impacts of combined application biochar and organic fertilizer on saline-alkali soil amendment and sunflower yield

【目的】探究生物炭与有机肥配施对内蒙古河套灌区盐碱土壤化学性质、养分含量以及向日葵产量的影响,为该地区土壤改良利用提供参考。【方法】试验于2022年6—10月在内蒙古自治区巴彦淖尔市河套学院试验基地开展,设置不施肥和生物炭(CK)、农民常规施化肥(CF)、常规施化肥配施生物炭(CFC)、30%有机肥替代化肥配施生物炭(MFC)、50%有机肥替代化肥配施生物炭(OFC)5个处理,分析各处理对盐碱土壤pH值、电导率、阳离子交换量、碱化度、可溶性盐离子含量、养分含量以及向日葵产量的影响。【结果】与CK相比,各处理土壤pH值无显著差异(P>0.05),CFC、MFC、OFC处理土壤电导率显著降低83%、78%、73%(P<0.05),土壤阳离子交换量显著提高38%、57%、53%(P<0.05),MFC、OFC处理土壤碱化度显著降低40%、36%(P<0.05);MFC、OFC处理土壤K^(+)含量显著提高100%、138%(P<0.05),Ca^(2+)含量显著提高61%、66%(P<0.05),Mg^(2+)含量显著提高71%、238%(P<0.05),SO_(4)^(2-)含量显著降低11%、12%(P<0.05),Na^(+)含量显著降低6%、3%(P<0.05)。CFC、MFC、OFC处理土壤养分含量显著提高(P<0.05),其中,MFC处理土壤全氮、碱解氮、速效磷、速效钾含量最高,分别为1.13、69.33、11.74、156.46 mg/kg;OFC处理土壤全磷、有机质含量最高,分别为0.49、13.44 g/kg。与CK相比,MFC处理向日葵单盘籽粒重显著提高30%(P<0.05)、百粒重显著提高22%(P<0.05),产量最高(3362.26 kg/hm^(2))。【结论】30%有机肥替代化肥配施生物炭处理能显著提高盐碱土壤阳离子交换量和K^(+)、Ca^(2+)、Mg^(2+)含量及养分含量,显著降低土壤电导率、碱化度和SO_(4)^(2-)、Na^(+)含量,显著提高向日葵产量,适宜内蒙古河套灌区盐碱土改良利用。

【Objective】To explore the effects of biochar and organic fertilizer combined application on the chemical properties,nutrient content,and sunflower yield of saline-alkali soil in Hetao Irrigation District,Inner Mongolia,and provide reference for soil improvement and utilization in the region.【Methods】The experiment was conducted from June to October,2022 at the Hetao College Experimental Base in Bayannur City,Inner Mongolia Autonomous Region.Five treatments were set up,including no fertilization and biochar(CK),conventional chemical fertilizer application by farmers(CF),conventional chemical fertilizer application combined with biochar(CFC),30%organic fertilizer replacement chemical fertilizer with biochar(MFC)and 50%organic fertilizer replacement chemical fertilizer with biochar(OFC).The effects of each treatment on the pH value,EC,CEC,ESP,soluble salt ion content,nutrient content,and sunflower yield of saline-alkali soil were analyzed.【Results】Compared with CK,no significant differences in soil pH values(P>0.05).Soil EC was significantly reduced by 83%,78%,73%in the CFC,MFC,OFC treatments(P<0.05),respectively.Soil CEC was significantly increased by 38%,57%,53%(P<0.05).Soil ESP was significantly reduced by 40%,36%in the MFC,OFC treatments(P<0.05).MFC and OFC treatments soil K^(+)content was significantly increased by 100%and 138%(P<0.05),Ca^(2+)content was significantly increased by 61%and 66%(P<0.05),Mg^(2+)content was significantly increased by 71%and 238%(P<0.05),SO_(4)^(2-)content was significantly increased by 11%and 12%(P<0.05),Na^(+)content was significantly decreased by 6%and 3%(P<0.05).CFC,MFC,and OFC treatments soil nutrient content was significantly improved(P<0.05).The MFC treatment had the highest soil total nitrogen,alkaline hydrolysis nitrogen,rapidly available phosphorus,rapidly available potassium content,at 1.13,69.33,11.74,156.46 mg/kg,respectively.The OFC treatment had the highest soil total phosphorus and organic matter content,at 0.49 and 13.44 g/kg,respectively.Single panicle grain weight of sunflower was significantly increased by 30%(P<0.05)and hundred-grain weight by 22%(P<0.05)in the MFC treatment,leading to a highest yield,at 3362.26 kg/hm^(2).【Conclusion】30%organic fertilizer replacement chemical fertilizer with biochar could significantly increase the CEC,K^(+),Ca^(2+),Mg^(2+)content and nutrient content,and significantly reduce the soil EC,ESP and SO_(4)^(2-)、Na^(+)content,the sunflower yield isignificantly increase.It is suitable for the improvement and utilization of saline-alkali soil in Hetao Irrigation District,Inner Mongolia.