Long Term Cultivation Effects On Nitrogen Dynamics In Polyhouse And Open Field Vegetable Growing Soils Of North-Western Himalayas

Aim: The present study was undertaken to assess the differences in the transformations of native nutrients between protected and open field conditions, affecting their availability to plants.Methodology: The geo-referenced soil samples were collected from farmers' field growing vegetables under polyhouse and adjacent open fields for last 5 to 6 years. Collected soil samples were analysed for organic and inorganic pools of nitrogen. Means of the different land use types were compared by using Tukey HSD Procedure.Results: Hydrolysable NH4-N was found as second most dominant form of nitrogen after amino acid-N, both under conventional and protected cultivation. In general, an increase was observed in hydrolysable NH4-N both under protected and conventional cultivation with respect to their fallow plotsInterpretation: Various fractions of nitrogen were found to be affected by the management practices and consequently status of nitrogen fractions was observed higher under polyhouse soil. Soil nutrient release under protected environment as compared to open field is necessary to observe the changes and adverse effect with ages of intensive cultivation under protected conditions.