Direct and residual effects of different combinations of poultry manure and single Super phosphate as Phosphorus and Sulphur sources on soil microbial activity

Abstract

Pot culture experiments were conducted to examine the best combination of poultry manure and chemical fertilizer as sources of phosphorus and sulphur on the microbial activity in a soil after sequential cropping system where main and residual crops were groundnut and sunflower respectively. To supply equal basis of phosphorus at 34 kg PzOs ha-1 and sulphur at 75 kg S ha'1 following treatments were used: L00o/o PM (Poultry Manurel, 750/o PM and 25o/o CF (Chemical Fertilizerl, 50% PM and 50% CF,25o/o PM and 750/o CF and 100% CF. Six treatments, including a no-P and S as control were replicated three times in a completell.' randomized design. After each crop soil was taken to estimate the microbial activity. In the main crop, the combination of 75 o/o PM and 25 o/o CF enhanced microbial population and biomass carbon content and was comparable with 500/o PM and 50 %o CF treatment. The soil organic carbon content was higher in sole poultry manure treatment. Same trend was observed in soil after residual crop also.