Physico-chemical and Biological Properties Of Soil in Different Cropping Sequences of Meerut and Bulandshahr District

Abstract

The depth wise soils of various cropping sequences from different locations were analysed to find the physico- chemical properties like soil texture, bulk density, pH, EC, CEC, organic carbon, total nitrogen, macro- micronutrients and biological properties (Bacteria, Fungi, actinomycetes count, microbial biomass, carbon and dehydrogenase). The soil samples collected from 30 locations of eight different cropping sequences varied in texture. The clay ranged from 9.32 to 33.64 and sand 47.68 to 67.86 percent. Substantial translocation of clay was noted specially in case of CRC (M) soil. The bulk density ranged from 1.21 to 1.42 Mg m·3 and it increases with declining organic carbon and increasing soil depth. The pH of soil samples varied from 7.4 to 9.0. The range of electrical conductivity of I :2 soil water extraction was 0.082 to 0.744 d Sm"1 at 25 °C. None of the soil was found in saline category. CEC of soil varied from 7.43 to 33.91 cmol (p +) kg-1 soil. Generally CEC was positively and significantly correlated with clay content. The organic carbon content which decline with soil depth varied from 1.8 to 9.6 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 from 38.44 to 134.05 kg ha-1 • It decline with soil depth. Total nitrogen in soil decline with increasing soil depth and ranged from 522.27 to 2924.78 kg ha- 1 • The available phosphorus and potassium ranged from 0.02 to 32.03 and 72.85 to 1291.41 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 7.939, Fe 1.947 to 16.923, Mn 0.482 to 8.259 and Zn 0.083 to 1.702 mg kg -I 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. Among the biological properties of soil, the range of bacteria varied from 2.0x 102 to 6.5x 108 , Fungi !.Ox I 02 to 8.6x I 04 and actinomycetes !.Ox I 02 to 8.0x 104 count g-1 soil. Microbial biomass carbon 75 to 400 flg g-1 soil and dehydrogenase activity 10 to 90 flg TPF g- 1day- 1 • All the microbial population, microbial biomass carbon and dehyrogenase activity decline as the soil depth increases.