水氮调控对陇中半干旱地区马铃薯产量及土壤环境的影响OA

To enhance potato yield andand improve soil conditions,a field experiment was conducted in Gaolan county from April to September 2023 in the semi-arid region of central Gansu.A two-factor experimental design was employed with three irrigation levels—W1(2 437.3 m3·hm-2),W2(1 824.2 m3·hm-2),and W3(1 297.7 m3·hm-2)—and three nitrogen application rates:N1(240 kg·hm-2),N2(180 kg·hm-2),and N3(120 kg·hm-2).A control(CK)treatment with high irri-gation(W1)and no fertilization was included,resulting in 10 total treatments.The results indicated:(1)water-nitrogen regulation significantly altered the distribution of available potassium and phos-phorus across soil layers and markedly increased nitrate and ammonium nitrogen content in the 10-20 cm layer.Under identical irrigation,N1 treatment yielded the highest soil nutrient content;(2)except for catalase,sucrase,urease,and alkaline phosphatase activities decreased with soil depth.Enzyme ac-tivities in the 0-20 cm layer were more sensitive to water-nitrogen regulation.Alkaline phosphatase activity peaked in the W1N2 treatment(60.66%higher than CK),sucrase and urease activities peaked under W1N1 treatment,while catalase activity reached its maximum in the 20-40 cm soil layer;(3)The W1N2 treatment produced the highest potato yield at 5.38 t·hm-2,representing a 42.17%in-crease over CK and a 149.58%increase over the lowest-yielding W3N3 treatment.Under identical ir-rigation conditions,nitrogen fertilizer productivity decreased with increasing nitrogen application rates.Collectively,the optimal water-nitrogen combination(W1N2)significantly increased yields and improved soil fertility by optimizing soil nutrients and enzyme activities,while reducing nitrogen appli-cation by 25.00%(60 kg·hm-2).These findings provide important technical references for the sus-tainable development of the potato industry in this region.