Optimal Nitrogen Rate Increases Water and Nitrogen Use Efficiencies of Maize under Fully Mulched Ridge–Furrow System on the Loess Plateau

Increasing water and nitrogen use efficiencies (i.e., WUE NUE) in dryland agroecosystems to maintain high agricultural output with lower environmental costs, such as minimal soil depletion nitrate-N residue, are key responsibilities assure food security for a growing global population. The impact of N rate on balance, nitrate grain yield, WUE, crop recovery efficiency (REN), agronomic fertilizer (AE), net economic return were examined maize production the rainfed Loess Plateau during 2011–2018. Field treatments included four application rates (N0, no applied; N100, 100 kg ha?1; N200, 200 N300, 300 ha?1). Results showed that compared N0, yield increased by 56, 110, 115% under respectively, corresponding improvements 5497, 10,878, 11,088 RMB ha?1 yr?1, respectively; significant difference was detected between N200 N300. Compared fertilization significantly through improving photosynthetic transpiration efficiency), but there REN gradually decreased increased, AE not changed N300 due leaf NUE. original storage at 0–300 cm depths, after seven years continuous experiments, treatment N0 enhanced 52 mm N100 had effect storage, depleted 73 109 mm, respectively. Our findings improves NUE less cost should be regarded economically optimal semiarid western China sustainable production.