Dissemination pattern of available nutrients and biological properties of soil under sugarcane–wheat cropping system

Abstract

The depth wise soils of sugarcane- wheat cropping system from four blocks of Moradabad district were analysed to find the physico – chemical properties like soil texture, bulk density, pH, EC, CEC, organic carbon, total nitrogen, macro & micronutrients. The pH of soil samples varied between 7.2 to 8.9. The range of electrical conductivity of 1:2 soil water extraction was 0.139 to 0.705 d Sm-1 at 25 0C. None of the soil was found in saline category. CEC of soil varied between 12.08 to 21.10 cmol (p+)/kg of soil. Generally, CEC was positively and significantly correlated with clay content. The organic carbon content which decline with soil depth varied between 2.4 to 7.2 g kg/ha 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 from 55.62 to 138.05 kg/ha. It decline with soil depth. Total nitrogen in soil decline with increasing soil depth and ranged from 522.27 to 2924.78 kg /ha. The available phosphorus and potassium ranged from 4.53 to 26.87 and 92.0 to 189.84 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 0.598 to 1.973, Fe 4.245 to 15.413, Mn 2.025 to 4.35 and Zn 0.213 to 1.961 mg kg/ha 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 2.1 to 5.6 x 106, fungi 1.8 x 104to 2.2 x 104 and actinomycetes 1.5 x 104 to 2.7 x104 count g-1 soil, microbial biomass carbon 255-290 μg /g soil and dehydrogenase activity 61 to 72 μg TPF g/day.