Exploring the potential of cold plasma for nitrogen enrichment in diverse soil types of Kerala

Atmospheric cold plasma is a novel green technology which generates highly reactive species at room temperature. Cold plasma exposure converts inert atmospheric nitrogen to plant available nitrates and ammonium ions in the soil. The present study aims to standardise voltage levels in major soil types of Kerala for achieving sufficient nitrogen enrichment with minimal impact on soil microbial activity. Selected soils were subjected to atmospheric cold plasma at low (5 kV), medium (10 kV) and high (15 kV) voltage levels for 10 min duration. Results have shown significant increase in available, total, ammoniacal and nitrate nitrogen content in all the studied soils with highest enrichment at 15 kV in most of the soils. Coastal sandy soil has shown the highest per cent increase in available nitrogen at 5 kV (214 per cent) and 10 kV (457 per cent), and black soil has exhibited the highest per cent increase at 15 kV (269 per cent). Optimum voltage level was found to be 5 kV for all the selected soils except coastal sandy soil, at which more than two-fold increase in available nitrogen content was observed with low energy consumption. Applied voltage level and inherent soil properties can play a decisive role on the effect of cold plasma treatment in all the soil types.