Potassium Dichromate Oxidizable Soil Nitrogen as a Chemical Index of Availability for Potato

Experiments were conducted in pot and field on acidic brown hill and alluvial soils to assess the relative suitability of different soil tests for nitrogen availability to potato. In hill soils from Simla, K₂Cr₂O₇ oxidizable N, total N and organic carbon values were almost equally correlated with the availability of soil N while alkaline KMnO₄ oxidizable N and nitrate N showed comparatively lower degree of correlation. In alluvial soils of Jullundur (Punjab), K₂Cr₂O₇ oxidizable N was better correlated than organic carbon with the availability of soil N while alkaline KMnO₄-N and total N showed less association with N availability.