水肥耦合对巴彦淖尔盐碱地紫花苜蓿产量、品质和经济效益的影响OA

To address the challenges of low soil fertility and inefficient water-fertilizer management in alfalfa(Medicago sativa)cultivation on moderately saline-alkaline soils in the Hetao Irrigation District in Bay-annur,Inner Mongolia,a two-factor field experiment was conducted.The experiment included three fertilizer levels(N-P₂O₅-K₂O:18.0 kg/hm2-91.5 kg/hm2-34.5 kg/hm2,54.0 kg/hm2-277.5 kg/hm2-103.5 kg/hm2,and 103.5 kg/hm2-463.5 kg/hm2-172.5 kg/hm2)and three irrigation levels(675,900,and 1 125 m³/hm2).The study systematically investigated the effects of water-fertilizer coupling on alfalfa growth,yield,forage quality,and economic performance.The results showed that both the medium fertilizer with high irrigation(F2W3)and low fertilizer with high irrigation(F1W3)treatments significantly increased plant height(P<0.05).Among all treatments,F2W3 achieved the best overall performance,producing the highest two-year total hay yield(44 498.69 kg/hm2)and the greatest economic return.However,irrigation water use efficiency(IWUE)and partial factor productivity of fertilizer(PFP)both declined with increasing water and fertilizer application rates.The best forage quality was obtained in the first harvest(May)under low fertilizer with medium irrigation(F1W2),while higher fertilizer application(F3)during later growth stages improved qual-ity.Based on principal component analysis and economic evaluation,the optimal water-fertilizer management strategy was identified as irrigation at 1 125 m³/hm2 combined with fertilizer application at 54.0 kg/hm2-277.5 kg/hm2-103.5 kg/hm2(F2W3).The optimized management model developed in this study provides a valuable scientific reference for alfalfa cultivition in saline-alkaline soils of the Hetao Irrigation District.