Studies on Manganese Fractions and their Utilization in Mewar Soils of Rajasthan

Soils of Mewar (Udaipur valley) region of Rajasthan were found to contain very low amounts of water soluble and exchangeable manganese, the latter being absent in some cases. Exch. Mn increased on air drying and storing of soils. Either of these forms showed no relationship with the manganese uptake by gram and wheat. Reducible Mn, which had a significant positive correlation with manganese content of gram plant though not of wheat, appears to be more important and practically constitutes the active form in the soils. Total Mn was significantly correlated with Mn in gram crop and it increased with silt+clay fraction. The organic (dil. alkali exttactable) fraction of soil had a low content of manganese. High Fe/Mn ratios in wheat plants are also indicative of a low availability of Mn in these soils.