~ 374 ~ The Pharma Innovation Journal 2021; 10(1): 374-378 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating: 5.03 TPI 2021; 10(1): 374-378 © 2021 TPI www.thepharmajournal.com Received: 28-11-2020 Accepted: 30-12-2020 RK Rathod Department of Soil Science and Agricultural Chemistry, College of Agriculture, Dhule, Maharashtra, India VP Bhalerao Department of Soil Science and Agricultural Chemistry, College of Agriculture, Dhule, Maharashtra, India PB Margal Department of Soil Science and Agricultural Chemistry, College of Agriculture, Dhule, Maharashtra, India RS Thakare Department of Soil Science and Agricultural Chemistry, College of Agriculture, Dhule, Maharashtra, India Corresponding Author: RK Rathod Department of Soil Science and Agricultural Chemistry, College of Agriculture, Dhule, Maharashtra, India Soil carbon fractions as influenced by pre and post emergence herbicide in sweet corn grown in vertisols RK Rathod, VP Bhalerao, PB Margal and RS Thakare Abstract Field experiment was conducted at Department of Agronomy, College of Agriculture, Dhule during Kharif 2019 to study the effect of pre and post emergence herbicides viz., atrazine, halosulfuron methyl, 2-4-D ethyl ester, pendimethalin and tembotrione on soil carbon fractions in sweet corn. All the treatments of pre and post emergence herbicide application were statistically at par in respect of organic carbon fractions viz., total organic carbon, Walkley-black carbon, water soluble carbon, soil microbial biomass carbon, permanganate oxidizable carbon, particulate organic matter carbon and humic acid and fulvic acid at harvest of sweet corn. The total organic carbon, Walkley-Black carbon, water soluble carbon, soil microbial biomass carbon, permanganate oxidisable soil carbon, particulate organic matter carbon, humic acid and fulvic acid was decreased by 9.86 to 10.90%, 17.62 to 18.15%, 12.02 to 12.32%, 13.15 to 14%, 9.57 to 9.94%, 30.23 to 30.93%, 25.30 to 26.74% and 26.64 to 28.15% in the treatments of pre and post emergence herbicides (T3 to T10) over the initial values of 104.2 g kg -1 , 5884 mg kg -1 , 82 mg kg -1 , 130 mg kg -1 , 138 mg kg -1 , 668 mg kg -1 , 13.91%m and 7.28%, respectively. The per cent decrease over initial value in organic fractions in the herbicide treatments at harvest of sweet corn was comparatively less as compared to the treatment of weed free check (T2). Keywords: Walkley-black carbon, water soluble carbon, soil microbial biomass carbon, permanganate oxidisable carbon, particulate organic matter carbon, humic acid and fulvic acid Introduction Soil organic carbon is of paramount importance for sustaining soil quality and long-term productivity of agricultural systems, measurements of changes in soil organic carbon under various nutrient management practices in intensive cropping system are the need of the day. Practices such as the addition of organic manures and/or residues, green manuring, inter- cropping with pulses, etc improve the content of soil organic carbon. The organic matter added to soil is subjected to microbial decomposition and intensity of decomposition is a function of soil moisture, temperature, and kind of organic input. Biological properties are critically important to the ecosystem functioning since they are involved in soil organic matter decomposition, nutrient cycling, and degradation of pesticides, such as herbicides (Araujo et al. 2003) [2] . Soil microbial biomass represents the active part of soil organic matter and is involved in several functions in soil, presenting a rapid turnover of soil C, N, and P; while enzymes are a suitable indicator of the catabolic activity of soil microorganism (Nannipieri and Badalucco 2003) [8] . Use of herbicides is a better supplement to conventional methods of weed control and forms an integral part of the modern crop production. It is evident that most of these herbicides may cause the reduction of sensitive populations of certain groups of biota in soil medium. It is believed that in cases where these herbicides are used to treat soils, they are considered harmful to nematode, earthworms and other biological organisms. They suppress the biodiversity of soil microbes, hinder the decomposition of soil organic matter and altered plant biomass. They also obstruct the biological activities of soil biota, photosynthetic, biosynthetic reaction, cell growth / divisions and molecular composition of soil biota (Usman et al. 2017) [14] . Though lot of information is available concerning the influence of herbicide on soil micro flora and fauna, very little information is available concerning their effects on soil organic carbon fractions. Keeping these fact in view, the present investigation was undertaken to study “Soil carbon fractions as influenced by pre and post emergence herbicide in sweet corn grown in Vertisols’’