Dynamics of Nitrogen Fractions in a Calcareous Vertic Haplustepts Under AICRP-LTFE Soils

With respect to forms of nitrogen it can be deduced that there was a declined in soil nitrogen levels. Ammonical-N and Nitrate-N status of LTFE soils in general decreased after long run, but it increased in the treatment T₁₀ due to fixation of atmospheric nitrogen by Rhizobium bacteria. Whereas available-N status in treatments which received FYM (T₈ and T₉), marginally increased. At initial stage of experiment (1^st year) available nitrogen status of LTFE soils falls under medium range (250-500 kg N ha^-1), but after 4^th year it decreased to lower range (<250 Kg N ha^-1) in most of the treatments and then after 8^th year all treatments exhibited low range of available nitrogen status in soil, except treatments which received FYM (T₈ and T₉) which showed medium range in available-N status of LTFE soils. It was established here that for maintaining N fertility of soil at long run, addition of FYM is essential with inorganic fertilizers. In LTFE soils the per cent depletion of different forms of nitrogen was interesting under all treatments. The total-N and O. C. showed negative depletion after a span of 8 year and available-N exhibited positive depletion in all treatments.