INFLUENCE OF PHOSPHAMIDON ON MICROBIAL BIOMASS CARBON, FDA AND SOIL RESPIRATION IN BLACK SOIL (ENTIC CHROMUSTERTS)

NISHA SAHU¹*, ASHA SAHU^2
1Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221 005, India
²Division of Soil Biology, Indian Institute of Soil Science, Nabibagh, Berasia Road, Bhopal 462 038, India
* Corresponding Author : nishasahu5@gmail.com

Received : 15-03-2016     Accepted : 02-06-2016     Published : 24-09-2016
Volume : 8     Issue : 39       Pages : 1796 - 1798
Int J Agr Sci 8.39 (2016):1796-1798

Keywords : Fluorescein Diacetate (FDA), Microbial Biomass Carbon (MBC), Organophosphate pesticide, Phosphamidon, Respiration, Soil
Conflict of Interest : None declared
Acknowledgements/Funding : The authors are thankful to Professor Surender Singh, Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India for providing instrumentation facility for research. We would also like to thank University Grant Commission and Department of Science and Technology, New Delhi (DST-INSPIRE) for their financial support to conduct the research work.
Author Contribution : None declared

Phosphamidon [2-chloro-2-diethylcarbamoyl-1-methylvinyldimethyl phosphate], is a broad spectrum, non-cumulative systemic organophosphorus pesticide widely used in agriculture. The potential harmful effect on soil microbial biomass and its activity was accessed in the vertisol soil under controlled laboratory conditions. We examined the effect of recommended (RD) and double the recommended doses (2RD) of phosphamidon on soil respiration, microbial biomass carbon (MBC) and fluorescein diacetate (FDA) hydrolyzing activity. The incubation study was carried out at 60 % of maximum water holding capacity of the soil sample at 28±2 °C for a period of 42 days. Our results indicated that MBC in soil increase significantly with time up to 14 days for all the treatment doses indicating adoption of microbes to use the pesticides as carbon or energy source. Thereafter, the value decline and reach the lowest 37% of the control on 42 days. There was no significant change in FDA and soil respiration, which increase with the period of incubation, but the value of pesticide treated where less compared to that of control. Our results provide the first evidence that Phosphamidon differentially affected the soil microbial community through inhibiting fungal and bacterial populations.