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Application of Different Organic Acids on Phosphorus Solubility from Rock Phosphate

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An incubation experiment was conducted on P solubilization from rock phosphate (RP) through different organic acids such as oxalic acid, citric acid, acetic acid, humic acid and sulphur in the laboratory of the Department of Soil and Environmental Sciences, KP Agricultural University Peshawar during fall 2011. The experiment was laid in a complete randomize design. There were three replications with six treatments. The organic acids were used at the rate of 2 % for 50 g RP in 250 ml conical flasks. These samples were kept in an incubator at 250c for four months and analysed for Mehlic-3 extractable P and pH values after 20 days interval. Statiscal analyses were made and maximum P concentration of 1.52% was observed in the treatment of oxalic acid mixed with RP followed by the treatments of RP mixed with humic acid with P concentration of 0.368% (Fig. 1). Rapid increases in P solubility from RP by mixing with oxalic acids were noted up to 60th days of incubation period and then remained stable after this period. Solubilization of P from RP by mixing with other organic acids was inconsistent. The pH in treatment of citric acid mixed with RP was noted as 5.64, followed by the treatments of oxalic acid with pH values of 6.31. A dramatic increase in pH value of 9.33 was observed in the treatment of RP mixed with humic acid. It is because the humic acid contains sodium salt and sodium hummate causes increase in its pH values.


Journal of Horticulture and Plant Research (Volume 2)
A. Jamal et al., "Application of Different Organic Acids on Phosphorus Solubility from Rock Phosphate", Journal of Horticulture and Plant Research, Vol. 2, pp. 43-48, 2018
Online since:
May 2018

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