Effect of nutrient management and soil type on stoichiometric imbalances across the Yangtze River Basin pear districts, China

Abstract

AbstractNutrition management affects soil carbon (C), nitrogen (N), and phosphorus (P) cycles, as well as their stoichiometry, causing further stoichiometric imbalances. However, research on the effect of nutrient management on soil stoichiometric imbalance is restricted to a single soil type, limiting our understanding of the interactions between these parameters. Therefore, we conducted a study comprising 212 sites throughout the Yangtze River Basin pear districts, for which nutrient management and soil properties were available under different soil types. Soil stoichiometric imbalances varied widely among the districts, with an average C:P imbalance value (C:Pim) of 6.67, higher than that of C:N imbalance (C:Nim; 6.43) and N:P imbalance (N:Pim; 2.83). Meanwhile, soil and microbial biomass stoichiometry, particularly for soil C:P and soil microbial biomass carbon and phosphorus (MBC:MBP), were significantly influenced by nutrient addition. Large N and P fertilizer inputs altered soil C:N and C:P in yellow–brown earth, while soil C:P was influenced by organic nutrient management in purplish soil. Moreover, adding organic nutrients altered the MBP, which further influenced MBC:MBP and MBN:MBP in saline–alkaline soil and yellow–brown earth. Furthermore, C:Pim increased with increasing organic nutrient input in purple soil and decreased with a large chemical fertilizer input in red soil. N:Pim and C:Nim were weakly associated with nutrient management in different soil types. In addition, nutrition management, soil type, soil properties, and microbe content collectively accounted for 45%, 32%, and 38% of the C:Pim, C:Nim, and N:Pim variation, respectively. Nutrient management also exerted a positive direct impact on C:Pim, while soil type elicited a negative direct impact on C:Nim and N:Pim. Meanwhile, all three stoichiometric imbalances were indirectly influenced by soil type. Taken together, our results indicate that soil stoichiometric imbalances, especially for C:Pim, are sensitive to nutrient management and soil type, providing novel insights into these imbalances that can inform the development of potential remedial strategies.