Department of Soils, Punjab Agricultural University, Ludhiana, Punjab.
Present address:1 Dept. of Civil Engineering, Punjab Agricultural University, Ludhiana.
Changes in soil fertility status as a consequence of differential levels of urea and manure addition to rice or wheat alone or to both the crops after the completion of two cycles of rice-wheat sequence in a Typic Vstipsamment are reported. Organic carbon (O.C) content of the soil registered an increase over its initial status. The increase in O.C. status was directly related with the quantity of urea and manures addition. Available N status increased with increasing N addition. Combined application of urea and FYM significantly enhanced O.C. and available N status over similar N addition through urea alone. Available P and K content of the soil decreased with successive rise in levels of N addition through urea whereas the status of these nutrients increased in plots receiving combined application of urea and manures. The influence of urea and manures addition was more pronounced in continuous manuring phase than direct and residual manuring phases. DTPA-extractable Fe, Mn and Cu decreased from their respective initial status. The magnitude of decline of these micro-nutrients narrowed down when 30 or 60 kg N was supplemented through manures, more so with FYM. On the other hand, available Zn status increased from its initial status since both the crops received basal dressings of ZnSO4.
Manuring phase, urea and blogas slurry, available nutrients, micronutrients
