Impacts of Paddy-based Cropping Systems on Soil Properties, Fertility Status and Nutrient Index in Utkal Coastal Plain of Odisha, India

AbstractThe impact of paddy-based cropping systems on soil properties, nutrient availability, and their nutrient index was studied in part of the Utkal Coastal Plain of Odisha. The four commonly occurring paddy-based cropping systems viz., paddy-fallow (P-F), paddy-pulses (P-P), paddy-pulses-oil seeds (P-P-O), and paddy-vegetable (P-V) were selected for the present study. Soil samples were collected from two depths (0-15 and 15-30 cm) and were analyzed for the major soil properties and nutrient status. Soils are of fine texture, dark grey to dark yellowish brown in color, massive in surface, and have a subangular blocky structure in the subsurface, with moderately to somewhat poorly drained conditions. The clay content of P-F and P-P-O surface soils (0-15 cm) was found to be lower (10.2 -36.6% and 5.1-42.6%) than that of P-P and P-V soils (31.9-48.1% and 8.1-61.1%), whereas the clay content in the subsoils (15-30 cm) of P-F was higher (20.6-48.7%) than in other land use systems. The subsurface soil had higher pH values and salt contents in all the land use systems. Soil organic carbon content (SOC%) was medium in surface soils (0.50-0.75%), except in the P-V system (0.40%), whereas subsurface soils were low (<0.5%). The mean AWC content increased from the surface (11.5 to 18.3%) to subsurface soils (12.7 to 19.0%) and was highest in P-P and lowest in P-P-O systems. Soil available nitrogen content was highest (165 to 205 kg ha-1) in surface soils compared to subsurface (77 to 139 kg ha-1) soils. Available phosphorus was medium in P-F and P-V cropping systems compared to other cropping systems. The available potassium was high in all the cropping systems except in the P-V system. The content of micronutrients was sufficient in all land use systems except for Zn. Nutrient index values for N were low (<1.5) in all land use systems, P was low in the P-P system, and medium (1.50-2.50) in other land use categories, while K was high in P-F and medium in other land uses. Therefore, adapting site-and crop-specific soil and nutrient management practices is necessary for attaining sustainable crop production in coastal regions.