Contrasting Effects of Nitrogen and Organic Fertilizers on Iron Dynamics in Soil after 38–Year Fertilization Practice

Various environmental factors and anthropogenic practices can affect the Fe biogeochemical cycles in soils. Nitrogen carbon states are closely associated with dynamics. However, we still have a limited understanding of complex response processes to long–term nitrogen– organic–fertilization regimes. This study investigated fraction distribution, as well link between nitrogen/carbon, bulk soil aggregates. The results showed that application nitrogen fertilizer increased contents water–soluble iron (Ws–Fe) carbonate–bound (Ca–Fe) various sizes aggregates, soybeans. decreased pH enhanced Feammox reaction nitrogen–fertilizer treatments were responsible for increase Ws–Fe Ca–Fe fractions. By contrast, organic Ca–Fe, while it Ox–Fe Or–Fe. Moreover, Or–Fe positively correlated organic–carbon micro–aggregates 0.053–0.25 mm <0.053 mm. These indicated use encouraged immobilization organo–inorganic compounds. alleviated retention induced by fertilizer. In conclusion, fertilization contrasting influences on mineralogy availability soil. is useful mechanism underlying interaction Fe’s phytoavailability different brown