Soil Environ. 31(1): 96-99, 2012 www.se.org.pk Online ISSN: 2075-1141 Print ISSN: 2074-9546 *Email: mukhan65pk@yahoo.co.uk © 2012, Soil Science Society of Pakistan (http://www.sss-pakistan.org) Formulation of single super phosphate fertilizer from rock phosphate of Hazara, Pakistan Matiullah Khan *1 , Shahid Ahmad 2 , Muhammad Sharif 3 , Motsim Billah 1 and Muhammad Aslam 1 1 WRRI, National Agricultural Research Centre, Islamabad 2 Natural Resource Division, Pakistan Agricultural Research Council, Islamabad 3 Department of Soil and Environmental Sciences, KPK Agricultural University Peshawar Abstract Phosphorus deficiency is wide spread in soils of Pakistan. It is imperative to explore the potential and economics of indigenous Hazara rock phosphate for preparation of single super phosphate fertilizer. For the subject study rock phosphate was collected from Hazara area ground at 160 mesh level with 26% total P 2 O 5 content for manual preparation of single super phosphate fertilizer. The rock phosphate was treated with various concentrations of sulfuric acid (98.9%, diluted or pure) in the field. The treatments comprised of 20 and 35% pure acid and diluted with acid-water ratios of 1:5, 1:2, 1:1 and 2:1 v/v for acidulation at the rate of 60 liters 100 kg -1 rock phosphate. The amount was prior calculated in the laboratory for complete wetting of rock phosphate. A quantity of 150 kg rock phosphate was taken as treatment. The respective amount of acid was applied with the spray pump of stainless steel or poured with bucket. After proper processing, chemical analysis of the products showed a range of available P 2 O 5 content from 9.56 to 19.24% depending upon the amount of acid and its dilution. The results reveal at that 1:1 dilutions gave the highest P 2 O 5 content (19.24%), lowest free acid (6 %) and 32% weight increase. The application of acid beyond or below this combination either pure or diluted gave hygroscopic product and higher free acids. The cost incurred upon the manual processing was almost half the prevailing rates in the market. These results lead to conclude that application of sulfuric acid at the rate of 60 liters 100 kg -1 with the dilution of 50% (v/v) can yield better kind of SSP from Hazara rock phosphate at lower prices. Keywords: Hazara rock phosphate, single super phosphate, phosphorus content, acidulation Introduction The P deficiency is wide spread in soils of Pakistan (Rashid, 2005). Pakistani soils contain less than 10 mg kg -1 available P (Memon, 1986), hence application of phosphatic fertilizers are recommended for better crop production. To combat the deficiency, annually 565.7 thousand nutrient tons of P fertilizers are imported against its requirement of 759 (Agri. Statistics, 2009). The continuous price hike in various P fertilizer was observed after year 2003-04. The trend of increase in prices became sharper during the years 2007-08 and 2008-09 when 107 and 232% increase over the year 2003-04 was recorded, respectively. The price of widely used DAP hiked from Rs. 997 to Rs. 1934 and Rs. 2787 with an increase of 93.9% and 179.5%, during the years 2007-08 and 2008-09 as compared with year 2003-04, respectively (Agri. Statistics, 2009). The price hike in P fertilizers ultimately affected the amount of consumption negatively by 35.7% and 53% during the years 2007-08 and 2008-09, respectively, as compared with year 2006-07. The decrease in consumption could be more drastic, negatively affecting the crop yields in the years, but the increase in procurement/ support prices (46.5% and 52%) compensated the grower. As a result, declining trend was observed in the wheat production. The unbalanced use of fertilizers particularly phosphatic fertilizer below the recommended dose is one of the reasons for decline in wheat production in Pakistan during 2007-08 (Aujla et al., 2010). Pakistan is well blessed by the Almighty Allah with rock phosphate deposits in Hazara area of Khyber Pukhtunkhwa province of Pakistan. It is basically tri- calcium phosphate [Ca 3 (PO 4 ) 2 ] insoluble in water and unavailable to plant (Brady, 1980; Das, 2005). The reserves are widespread in Hazara, Taranawai as schists, shales or limestones at Kakul, Guldaman, and Legerban villages of district Abbottabad in the forms of dolomites or phosphorites, and in Thandiani in the form of orthoquartizites and limestones (Javed et al., 2008). The so far reported exploration indicates that total reserves are about 35.7 million tons including inferior and proven quality (PMDC, 2006). Keeping in view the huge foreign exchange incurred on the import of P fertilizers and the available rock phosphate reserves in the country, it is imperative to explore the extent of P 2 O 5 release, the amount of acid required for complete