Effect of long term manure and fertilizer application on availability of phosphorus and its fraction in long term fertilizer experimental field under finger millet-maize cropping system in Karnataka

AICRP on long-term fertilizer experiment ie finger millet-maize cropping system was initiated at the Zonal Agricultural Research Station, GKVK, UAS, Bengaluru during 1986–87. Incorporation of organic and inorganic fertilizers resulted in significant variation of available phosphorous and its fractions as compared to control. Growing of finger millet-maize cropping sequence continuously over the years with the use of inorganic fertilizers and farm yard manure markedly increased available P content of soil over the control. There was a considerable build up of available phosphorus (194.06 kg/ha), aluminium bound phosphorus (118.52 kg/ha), iron bound phosphorus (167.55 kg/ha), occluded phosphorus (85.74 kg/ha), calcium bound phosphorus (87.15 kg/ha) and total phosphorus (568.85 kg/ha) at application of higher dose of phosphorus.