Evaluation of soil extractants for estimating manganese availability to wheat in alluvial soils of Punjab

A study was conducted to explore different soil extractants for manganese availability to wheat (Triticum aestivum cv. PBW 343) on alluvial soils. Five chemical extractants were tested for their ability to predict the response of wheat to Mn application in coarse to medium-textured alkaline alluvial soils. Four out of five extractants were found promising for the estimation of critical levels of available Mn in these soils. The highest co-efficients of correlation between available Mn and relative grain yield was with 1M NH₄HCO₃ + 0.005M DTPA (r=0.510*), followed by Mehlich-3 extractant (r=0.496*), 0.005M DTPA (r = 0.479*) and, 0.2% Hydroquinone +1N NH₄OA_c (r=0.466*). The critical deficiency level of soil available Mn with 1M NH₄HCO₃ + 0.005 M DTPA, Mehlich-3 extractant, 0.005 M DTPA and, 0.2% hydroquinone + 1N NH₄OA_c which separated the responsive soils from non-responsive ones were 4.1, 7.6, 3.0 and 15.0 mg kg⁻¹ soil respectively.