Simulation of Nitrogen Mineralization in the Below-Ground Food Webs of Two Winter Wheat Fields

Food webs in conventional (high-input) and integrated (reduced-input) farming systems were simulated to estimate the contribution of soil microbes and soil fauna to nitrogen mineralization during the growing season. Microbes accounted for approximately 95% of the biomass and 70% of total nitrogen mineralization in both management practices. Among the soil fauna, amoebae and bacterivorous nematodes were the most important contributors to nitrogen mineralization. The contribution of nematodes showed more temporal and spatial variability than the contribution of amoebae. The model calculated nitrogen mineralization rates close to the observed rates for both fields and depth layers. In the integrated plot there were relatively high rates of mineralization in the 0-10 cm layer compared with the 10-25 cm layer, whereas in the conventional plot no differences were observed between depth layers (...)