The top layer of the soil consists of large microbial biomass and hence great microbial activity which plays a significant role in proper functioning of this ecosystem. In addition, these microorganisms are also associated with various metabolic activities and in the transformation of different biological products such as waste materials and synthetic organic compounds into the harmless products like intermediates of Krebs cycle; malate and also CO. Thus, these organisms are the producers of a number of beneficial enzymes viz: dehydrogenase, amylase, protease, urease and key activators of various biogeochemical cycles of the nature hence play a vital role in maintaining fertility and health of the soil. Various natural and anthropogenic factors are established to alter activities of these enzymes. Among several important soil enzymes, protease and urease of nitrogen biogeochemical cycle are the enzymes which play crucial roles in nitrogen mineralization and its availability in the soil, thereby promoting plant growth and development responses. Repeated use of insecticides and frequent release of metalloids into the soil are shown to affect adversely to these enzymes. Thus, present study aims to assess the impacts of chlorpyrifos, cypermethrin and arsenic, which is applied at the rate of 50 mg kg', 40 mg kg" and 3.5 mg kg' over the time period of 50 days, on the activities of both protease and urease. In regard, soil samples from the paddy growing field have been collected and the water content of it was maintained up to 60% of water holding capacity. These soil samples were then exposed to five different treatments such as As, As+Chl, As+Cyp, As+Chl+Cyp and non-treated Control (Distilled water). Activities of both protease and urease in the treated soils were measured following standard protocol, after 1, 10, 20, 30, 40 and 50 days of incubation. Data were analyzed by two-way ANOVA; following DMRT at P<0.05 level using SPSS (Ver 16.0). Accumulated data revealed the significant impacts of days of incubation, treatments applied, and interaction between these two, on the activities of both the enzymes. Application of TI and T3 lead remarkable enhancement in the activities of urease and protease enzymes, than the T2 and T4.
Cite this article:
Shweta, Kulbhaje and Keshavkant (2016). Influence of Metalloid and Insecticide(S) on Urease and Protease, Key Enzymes of Nitrogen Biogeochemical Cycle. Journal of Ravishankar University (Part-B: Science), 29(1), pp.148-149.