Effects of Organic Acids Application on Olsen- extractable P and Eggplant (Solanum melongena) Yield

This study investigated two low molecular weight organic acids (LMWOA), oxalic and citric acid, ability to mineralize fixed P in soils and the effects on production of eggplant when compared to conventional triple superphosphate fertilizer (TSP). Two calcareous soils were used: An alkaline (pH 7.6-7.8) Vertisol in the Houston Black soil series and a slightly acidic (pH 6.5-6.8) Mollisol in the Tarpley soil series. The Houston Black soil test indicated no significant difference in extractable P when comparing treatments of oxalic, citric acid or applied triple superphosphate (TSP) fertilizer (P > 0.05). Similarly, eggplant yields indicated no significant difference (P > 0.05) between treatments for this soils series. In the Tarpley series, LMWOA treatments produced significantly less extractable P and eggplant yield (P < 0.05) when compared to applied TSP fertilizer.