Nitrogen Mineralization in Profiles of Differently Managed Soil Types

Publisher Website
Google Scholar
Abstract
Nitrogen mineralization kinetics and relations between potentially mineralizable N and chemical availability indices have been studied mainly in surface soils. In this study, the rate of mineralization was measured, by incubation techniques, in various soil types and soil depths, in order to evaluate the contribution of different soil layers to mineral nitrogen (N) of the whole root zone and to relate the rate parameters obtained to various soil N fractions. Soil layers of 60 to 120 or 160 cm contributed about 30% of the N mineralized in the whole soil profile. Ammonium accumulated and its nitrification was delayed in deeper soil layers of several profiles. Several rate equations were fitted to the experimental data. The first order rate constant varied from 0.02 to 0.10 week−1, without any consistent trend. Similar random variations of rate parameters were observed in other models with two or more parameters. The potentially mineralizable N (No) of one‐parameter models was highly and better correlated with the amount actually mineralized in 32 weeks of incubation and with various N forms in soil than the No obtained from two‐parameter models. Total N weighted with respect to soil layer depth was the best estimate of N mineralized in soil profiles.
Funding Information
  • United States - Israel Binational Agricultural Research and Development Fund

This publication has 1 reference indexed in Scilit: