Figure 3
From: The fate of fertilizer nitrogen in a high nitrate accumulated agricultural soil
Changes in recoveries of 15N in the soil as NH4+-N, NO3−-N, extractable organic N (EON), microbial biomass N, incorporated into SOM, mineral fixed N fractions and loss during the 120-day lab incubation after the addition of (15NH4)2SO4 alone (+15NH4+) or combined with ryegrass (+15NH4++Ryegrass) to the tested soil.
15N recovery in SOM pool was calculated as the difference of recoveries in “non-extractable N” and “microbial biomass N + mineral fixed N”. Nitrogen loss is the unrecovered 15N neither in extractable nor non-extractable pools. Numbers in the areas are the corresponding 15N recoveries in relevant N pool at the related incubation time.
