Abstract:
A modified chemical laboratory method to assess the potentially available N in soil likely to be available during the growing season of crop has been proposed. Fresh or air dried soil samples were autoclaved in 0.01 M Ca Cl2 solution at 121 °C for 16 hours. The samples were then filtered and analyzed for NH4, NO3 and NO2-N by automated colorimetric method. The levels of NH4-N in both air dried and fresh soils increased after autoclaving. There were also changes in the NO3 and NO2-N content of the soils. The inorganic N content of the fresh and air dried soils were correlated with total N, total C and total biomass C (r = 0.72 - 0.74, 0.86 - 0.89 and 0.79 - 0.81, respectively). The correlation with clay was poor (r = 0.21 - 0.28) and was negative with soil pH (r = 0.64 - 0.58).
Page(s):
65-71
DOI:
DOI not available
Published:
Journal: Gomal University Journal of Research, Volume: 13, Issue: 2, Year: 1993