Assessment of Soil Quality and Organic Carbon Stocks under Different Land use Systems in Sub Humid Southern Plains of Rajasthan

Abstract

newlineResearch database information regarding soil quality, organic carbon, and nitrogen stocks, and soil properties under different land-use systems (LUSs) is essential for the sustainable utilization of existing soil resources. The main objective of this study was to examine the variation in measurable soils properties with carbon and nitrogen storage patterns and soil quality indices (SQIs) under different prevailing land-use systems in the Sub Humid Southern Plains of Rajasthan. Preliminary survey and group interaction with the farmers about land-use, cropping history were used to select the six LUSs, namely barren land (BL), agricultural (AG), agri-horticulture (AH), horticultural (HL), grassland (GL), and natural forest (NF) land-use. A total of 120 composite soil samples [6- land-use systems, 4- soil depths (0-20, 20-40, 40-60, and 60-80 cm), and 5-replication for each LUS] were randomly collected from the selected LUSs for laboratory analysis. The study area was dominated by sandy clay loam soil texture. Soil pH ranged from 7.74 to 8.27 showed slightly alkaline soil conditions under all the LUSs. The EC was not a limiting factor for plant growth and productivity of field crops in the study area. The lowest and highest soil bulk density was observed under natural forest (1.51 Mg m-3), and barren land-use (1.62 Mg m-3), respectively. The maximum total soil porosity, water holding capacity, moisture content at different water potentials, and plant available water recorded under natural forest land-use soil, while barren land-use soil was least in all these soil parameters. The calcium carbonate (CaCO3) varied from 3.12 to 3.30 per cent under different land-use systems with a non-significant difference. However, a significant increasing trend was recorded with soil depth which might be associated with the precipitation of dissolved carbonates in lower soil depths. The CEC, available N, P, K, DTPA extractable soil micronutrients (Zn, Cu, Fe, Mn) and soil organic carbon contents were higher in natural fo