Assessment of soil quality and nutrient dynamics under conventional and protected agriculture

Abstract

newline Protected cultivation is gaining momentum especially for vegetable cultivation in Himachal Pradesh. Therefore the present study was undertaken to assess the soil quality inside polyhouses vis a vis under conventional cultivation so as to ascertain the effect of intensive cropping and the management practices being followed by farmers under these two systems. The main objectives of this study were to assess the effect of conventional and protected systems of farming on soil quality and to study N, P and K dynamics under conventional and protected systems of farming. To accomplish this, 25 sites of district Kangra were selected. All the required physical, chemical and biological parameters of soil quality were analysed and key indicators were identified using multivariate statistical analysis for computing the soil quality index. Wide variations in the soil health indicators were observed among different sites. Likewise, differences existed in the quality indicators between the samples from the protected and open conditions at number of sites. Higher salt accumulation (EC) was observed under protected conditions as compared to conventional system, though the differences in other properties were only conspicuous for some of the parameters. Among different nitrogen fractions, amino acid-N was the dominant fraction and contributed about 25 and 30% towards total-N and total hydrolysable-N, respectively. In case of P fractions, inorganic fractions constituted about 84.2% of total P. Water soluble-K, Exchangeable-K and non exchangeable-K contributed about 0.12, 0.59 and 3.05% towards total-K, respectively. As per multivariate statistical analysis techniques,organic carbon (OC), soil pH, EC, MWD and total K were found to be the most important indicators contributing towards soil quality.The mean soil qualityindex (SQI) values in Baijnath, Bhedu-Mahadev, Bhawarna, Kangra and Dharamshala blocks were 0.852, 0.816, 0.722, 0.823 and 0.794, respectively under protected cultivation. Similarly the SQI for the respec