Effect of sulphuric acid on control of lime induced iron chlorosis in groundnut

To investigate the effect of sulphuric acid on control of lime induced iron chlorosis in groundnut, cv. TCGS-37 was grown in calcareous soil with different levels of sulphuric acid (0.0, 1.0%, 1.5%, 2.0% and 2.5%). Application of H₂SO₄ to soil decreased iron chlorosis and significantly increased chlorophyll content and active iron in leaves. Acid application increased the total dry matter and pod yield. H₂SO₄ at 2.5% concentration recorded higher dry matter compared to other treatments. The increase in pod yield can be attributed to increased availability of Fe, P and chlorophyll contents. Acid application of above 2.0% raised the DTPA-Fe level of the soil above the critical limit of 4.5 ppm by decreasing soil pH, CaCO₃ content and HCO₃ concentration. The results indicated that soil application of 2.5% H₂SO₄ was an effective means of controlling lime induced iron chlorosis in groundnut.