Land use influences soil morphological and physicochemical properties of salt–affected profile in Northwest India

Globally, soil salinity impedes crop growth and agricultural productivity and the impact of climate change has worsened it. Tree, agroforestry and long–term grass–based vegetation cover impact on morphological and physicochemical properties of the saline soils are rarely addressed. Morphology, structure, consistence and root features, CaCO3 and organic C (OC) stock and physico–chemical properties of the eight soil profiles with pedogenic soil horizons were studied after 25 years of the imposition of Frass (Tamarix articulata), Kainth (Feronia limonia), Eucalyptus tereticornis, Grassland, Karonda (Carissa carandas) –mustard (Brassica juncea), Bael (Aegle marmelos)–mustard (Brassica juncea), Aonla (Emblica officinalis) – mustard (Brassica juncea) and Prosopis juliflora – mustard (Brassica juncea). Tamarix and Eucalyptus showed significant increase in organic C (OC) content; and decline in bulk density, and lower CaCO3 content in the surface and near–surface horizons of soil profile. The highest OC stock in the soil profile was recorded under Eucalyptus (115.2) followed by Frass (96.0), and Karonda–mustard (88.2 Mg C ha–1) upto 1.6 m soil depth for all profiles. Similarly the CaCO3 stock was greater in the soil profile of Prosopis–mustard (2977.1) followed by Kainth (2861.6) and Beal–mustard (2960.1 Mg C ha–1). Electrical conductivity, concentration of Ca2+, Mg2+, HCO3– in soil water saturation paste extract and CaCO3, OC in soil were the most important soil variables explaining 95% of the data variability in data reduction techniques. This study concludes that the Eucalyptus, Tamarix articulata and Carissa carandas plantation can be promising option for greening barren saline landscapes to achieve greater carbon sequestration potential.