Self-Regulation of Soil Enzyme Activity and Stoichiometry under Nitrogen Addition and Plastic Film Mulching in the Loess Plateau Area, Northwest China

Soil extracellular enzyme activity (EA) and its eco-enzyme stoichiometric ratio (ES) are extremely sensitive to environmental change. This study aimed clarify the change law of EA ES in soil with different nitrogen addition levels under plastic film mulching, optimize application amount fertilizer that was used. Based on location experiment mulching fertilization has been ongoing since 2015, samples were collected from depths (0–10 cm, 10–20 cm 20–30 cm) during harvest period spring maize October 2021. Four activities (β-1,4 glucosidase (βG), β-1, 4-N-acetylglucosidase (NAG), leucine aminopeptidase (LAP) alkaline phosphatase (AP)) involved carbon (C), (N) phosphorus (P) cycling at (0, 90, 150, 225 300 kg·hm−2) studied two planting patterns no (LD) (PM). The latest discovery this is C, N P similar cm). Both EC:P area less than 1:1, indicating limited by P. Comprehensive analysis showed a level kg·hm−2 beneficial balance nutrients improvement harvest. At same time, PM can effectively improve more conducive nutrients. Redundancy (RDA) strongly correlated pH, organic (SOC), total (TN) (TP). Most importantly, revealed enzymes arid semi-arid areas constantly self-regulated nitrogen, which provided theoretical technical support for efficient use condition mulching.