Abstract-

P hosphorus (P) is second macro-nutrient considered essential for plant growth. Physiological functions such as cell division and development, photosynthesis, the breakdown of sugar energy and transfer within the plant depends on P (Sharma, 2005). The application of P to crops increases root development, water-use efficiency and the plant's resistance to moisture stress. Phosphorus also contributes to straw strengthening in cereal crops as well as crop quality, especially in forages and vegetables.Most of the soils in Pakistan are alkaline calcareous, a condition proven to P fixation, making P deficiency a widespread phenomenon (Sharif et al., 2000; Rashid, Abstract | Field experiments were conducted during 2015-16 at National Agricultural Research Center Islamabad to evaluate the availability of P from different particle size of Hazara rock phosphate (HRP) by manual preparation of Single Super Phosphate (SSP) through the procedure already established by the author and testing its efficacy in comparison to DAP on rainfed wheat. Almost 50 bags of SSP were prepared using formula "100 kg of indigenous HRP with total P 2 O 5 content of X and mesh size 160 when treated with 60 liters (50% diluted) H 2 SO 4 (volume/volume), followed by proper curing, yields SSP of almost X/2 % extractable P 2 O 5 " . The P was applied @ 57.5 kg P 2 O 5 ha -1 both from prepared SSP and DAP to wheat crop on equal P 2 O 5 basis. Also, Phosphate Solubilizing Bacteria (PSB) were tested in this experiment for yield and P uptake of the crop. The results showed that smaller the mesh size of HRP 200 mesh gave maximum available P 2 O 5 14.27% followed by 160 mesh with 14.21%, from the stock grade HRP containing 28% total P 2 O 5 . The free acid contents were equal and lower (5%) in the prepared SSP for mesh size 160 and 200, against 6.3% when mesh size was 120. The SSP application as P source increased grain yield and total dry matter yield 2.5% and 4.7% over DAP, respectively. Similarly, SSP application enhanced P uptake of crop by 5.6% over DAP, however, no increase in postharvest soil P concentration was recorded. Seed inoculation with PSB significantly increased grain and dry matter yield. It can be concluded from the study that good quality of SSP can be manually prepared from HRP which may increase the yield comparable to DAP.