Physico-Chemical and Biological Properties of Soil under Sorghum – Wheat Farming System of Bulandshahr and Meerut Districts in Uttar Pradesh

Abstract

The depth wise soils of sorghum- wheat farming system from different locations were analyzed to find the physico – chemical and biological properties like bulk density, pH, EC, CEC, organic carbon, macro- micronutrients and bacteria, fungi and actinomycetes. The pH of soil samples varied from 7.9 to 8.7 and range of electrical conductivity of 1:2 soil water extraction was 0.139 to 0.347 d Sm−1 at 25°C. None of the soil was found in saline category. CEC of soil varied from 9.21 to 18.25 c mol (p+) kg−1 and was positively and significantly correlated with clay content. The organic carbon content which declined with soil depth varied from 2.4 to 7.5 g kg−1 soil. Organic carbon was correlated positively and highly significantly with available nitrogen, total nitrogen, positively with available P, K, micronutrient and microbial biomass carbon and negatively with bulk density and CEC in all the cropping sequences soil. The available nitrogen ranged between 41.25 to 107.49 kg ha−1. It decline with soil depth. The available phosphorus and potassium ranged between 4.48 to 14.84 and 68.30 to 325.00 kg ha−1and declined with increasing soil depth. Among the different cationic micronutrients with exception of zinc the availability of rest micronutrients was in sufficiency range. In some case the availability of zinc was in deficient range. DTPA extractable Cu ranged from 0.075 to 1.983, Fe 2.221 to 8.474, Mn 0.408 to 5.551 and Zn 0.107 to 1.232 mg kg −1 soil. The availability of these micronutrients declined with increase in soil depth. Except Mn and available potassium others nutrients were significantly and positively correlated with organic carbon. The biological properties of soil, the range of bacteria varied from 2.0x 102 to 6.5x 108, fungi 1.0x 102 to 8.6x 104 and actinomycetes 1.0x 102 to 8.0x104 count g−1 soil. Microbial biomass carbon 75 to 400 μg g−1 soil and dehydrogenase activity 10 to 90 μg TPF g−1day−1. All the microbial population, microbial biomass carbon and dehyrogenase activity declined as the soil depth increases.