@article {KNZ00618, title = {Carbon and nitrogen mineralization in tallgrass prairie and agricultural soil profiles}, journal = {Soil Science Society of America Journal}, volume = {62}, year = {1998}, pages = {942 -951}, abstract = {In situ mineralization of N may contribute significantly to total inorganic-N pools deep in the soil profile. We conducted long-term laboratory incubation experiments to evaluate the net C and N mineralization in soils collected from various depths in tallgrass prairie and agricultural fields of the same geological materials and soil type. Samples were packed to a bulk density of 1.4 g cm-3 in 5-cm-diameter by 10-cm-long cores. The cores were incubated at 35{\textdegree}C for 40 wk in sealed containers. Net C mineralization was measured by evolved CO2, and N mineralized was measured by periodic leaching with NH+4 and NO-3 measured in the leachate. Carbon and N mineralization in the surface horizon were greater in the tallgrass prairie than in the agricultural soil. In both the tallgrass prairie and agricultural soil profiles, C mineralization was least at the water-table depth. Carbon mineralization was described by a first-order kinetic model, but N mineralization was described better by a consecutive (sigmoidal) reaction model. At most depths, the ratios of potentially mineralizable organic C (C0) to total organic C (C0/TOC) and potentially mineralizable organic N (N0) to total N (N0/TN) were greater in the agricultural soil profile than in the tallgrass prairie soil profile. The C0 and N0 in the surface soil (0{\textendash}0.2 m) represented 11.6 and 12.2\% of the total organic C and N pools for the tallgrass prairie soil profile, respectively, and 21.0 and 10.2\% of the total organic C and N pools for the agricultural soil profile. Management practices affected the mineralization potentials and rates of both the surface and subsurface soils.}, keywords = {LTER-KNZ, tallgrass prairie}, doi = {10.2136/sssaj1998.03615995006200040014x}, author = {Ajwa, H.A. and C. W. Rice and Sotomayor, D.} }