Physicochemical properties and stoichiometry of Mollisols in responses to tillage and fertilizer management

Understanding the influence of tillage and fertilizer management on soil physical properties, and their roles in soil stoichiometry are critical for estimating the ecological implications of agricultural management. The study investigated the 3-yr effects of tillage and fertilizer management on soil physical properties, nutrients, and stoichiometry. The study included two tillage methods: rotary tillage (R) and deep tillage (D), with three fertilizer management: chemical fertilizer (N), chemical fertilizer + straw returning (S), chemical fertilizer + straw returning + organic fertilizer (M). Samples were collected at three depths: 0–15, 15–30, 30–50 cm. Results indicated that treatment effects were better at depth 0–30 cm than at 30–50 cm. The D significantly increased the soil C: N but decreases the C: P because nutrient fixation state was broken. The M had more effect on soil nutrient concentrations and stoichiometry. Effects of tillage and bulk density were positively correlated with soil nutrient concentrations, while moisture content and compactness were positively correlated with the soil stoichiometric ratio. Fertilizer management is the main factor to control soil nutrient and stoichiometry while using organic fertilizer under deep tillage can improve nutrients and maintain the stability of Mollisols ecosystem.