Comprehensive study on physico-chemical soil analysis for optimizing paddy (Oryza sativa L.) cultivation in Kamrup (Metro) district of Assam, India

Rice being the staple food in Assam, its productivity should be increased for the availability of the common people. The main objective of this study is to compare the qualities of soil samples and to correlate the results with the production (per year) of paddy (Oryza sativa) from 3 different studied areas. The soil samples were collected during March-May, 2023. The oven dry method and drying and weighing method are used to determine bulk and particle densities respectively. The electrical conductivity and pH of the soil samples are determined using a benchtop conductivity meter and pH meter. Walkley-Black chromic acid wet oxidation method and methylene blue method are used to determine the organic carbon and cation exchange capacity (CEC) of soil samples respectively. Nitrogen, phosphorus, and potassium of the soil samples are estimated using the instrument Mridaparikshak. The moisture content, bulk density, particle density, soil porosity, cation exchange capacity (CEC), pH, electrical conductivity, nitrogen, P₂O₅, and K₂O are observed in the range of 24.69 % to 39.42 %, 1.12 g cm^-3 to 1.25 gcm^-3, 1.83 gcm^-3 to 1.99 g/cm^-3, 33 to 43, 2.8 × 10^-5mol dm^-3to 11.7×10^-5 mol dm^-3, 7.4 to 8, 0.23 dS/m to 0.40 dS/m, 0.645% to 1.49%, 213.20 kg/ha - 235.14 kg/ha, 17.92 kg/ha - 20.44 kg/ha and 148.92 kg/ha -164.45 kg/ha respectively. The soil characterized by moisture content =27.52 %, bulk density=1.25 gcm^-3, particle density =1.86 g cm^-3, porosity =33%, cation exchange capacity =11.7 x 10^-5 mol dm^-3, pH {(1:5) at 210C} = 7.9, electrical conductivity = 0.40 dS/m, organic carbon =0.825 %, organic matter =1.42 %, N =235.14 kg/ha, P₂O₅ = 20.44 kg/ha and K₂O =164.45 kg/ha showed good yield.