Abstract
Rock phosphate is the cheapest source of phosphorus nutrition. But its water soluble P is low. To enhance plant available P
from rock phosphate afield experiment was performed to determine the impact of de-waxed filter cake press mud (organic
amendment) for the release of available P from insoluble P source (local Hazara rock phosphate) in normal soil (pHs= 8.15,
ECe= 1.28 dS m-1
, SAR = 4.77 mmol L-1
, saturation percentage = 29%, Available P = 7.1 mg kg-1
and sandy clay loam texture).
The research was carried out using randomized complete block design (RCBD) with five treatments replicated thrice namely
T1, recommended basal NPK; T2, NP0K (control); T3, NK + Rock Phosphate Red (RPR); T4, NK + Filter Cake Press mud
(FCP) and T5, NK + Rock Phosphate Red (RPR) + Filter Cake Press mud (FCP). Results suggested application of recommended
doses of NPK proved superior in terms of enhancing plant height, total biomass, biological yield, leaf area index and soil
available P. However, soil organic matter and P content remained highest in treatments receiving organic amendments. Based
on this study, application of organic nutrition i.e. dewaxed filter cake press mud (FCP) proved beneficial for the release of P
from local red rock phosphate and also enhanced soil organic carbon fraction in similar growth environment.
