The Effect of Drying–Wetting Cycles on Soil Inorganic Nitrogen Transformation in Drip-Irrigated Cotton Field Soil in Northwestern China

Drip irrigation under plastic mulch is widely used and leads to periodic drying–rewetting (DW) cycles in Xinjiang, Northwest China. However, the effect of different wet dry alternation types on soil inorganic nitrogen transformation not clear. Studying these issues only provides reference for formulation fertilization systems but also great significance reducing non-point source pollution. An incubation experiment was conducted 2018 Baotou Lake farm Korla City, with drip-irrigated cotton (Gossypium hirsutum L.). The treatments were designed comprising three parts: (1) DW intensity (Q100, Q90, Q80, Q70, Q60); (2) frequency (P3d, P5d, P7d, P9d, P11d); (3) wetting time (P1m, P3m, P5m). results revealed that contents NH4+ NO3− decreased increase highest Q100 treatment. rate net N mineralization intensity. (7.02 mg kg−1 d−1) found Q70 treatment process 3.03 d−1 Q60 process, respectively. higher (P3d). P3d P5d longer content NH4+, NO3−, (P5m). shorter from process. These demonstrate a reasonable intensity, frequency, could effectively promote absorption reduce losses drip irrigation.