Int.J.Curr.Microbiol.App.Sci (2018) 7(5): 2435-2445 2435 Original Research Article https://doi.org/10.20546/ijcmas.2018.705.280 Influence of Different Organic Amendments on Fe, Mn, Cu and Zn Availability in Indian Soils Sumona Ojha 1* , Sushant Sourabh 2 , Shubhadip Dasgupta 3 , Dilip Kumar Das 4 and Arindam Sarkar 5 1 Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur-741252, India 2 Department of Agricultural Extension, Dr. Rajendra Prasad Central Agricultural University, Pusa-848125, India 3 AICRP on STCR, Directorate of Research, Bidhan Chandra Krishi Viswavidyalaya, Kalyani-741235, India 4 Institute of Agricultural Science, University of Calcutta, Kolkata-700019, India 5 Regional Research Station (R and L Zone), Bidhan Chandra Krishi Viswavidyalaya, Jhargram-721507, India *Corresponding author ABSTRACT International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 05 (2018) Journal homepage: http://www.ijcmas.com This experiment was carried out to investigate the stabilizing influence organic amendments on soil reaction and micronutrient availability. Three different soil types (viz. acid, neutral and sodic soil) were considered for our experiment to represent soils of the whole country. Soils were incubated with FYM and vermicompost at different doses and incubated at field capacity for 4 weeks. Subsamples at predetermined duration were analyzed for soil reaction, organic carbon (OC), available micronutrients, microbial biomass carbon and nitrogen. The pH for acid soil was found to increase from 5.40 to 5.91, whereas it showed a decreasing trend for neutral (from 7.58 to 7.09) and sodic soil (from 9.36 to 8.81). This change of pH was closely related with change in soil OC content at different durations. However acid and neutral soil reported stronger correlation (R 2 =0.93 and 0.94 respectively) than sodic soil (R 2 =0.71). All three soils contained micronutrient well above the critical limit, indicating higher availability of them. Still their content was significantly modified during the entire experiment. However the modification was not merely similar for all the micronutrient, and varied according to their elemental chemistry. The concentration of available Fe (12.11-15.26, 7.51-8.46 and 6.37-7.93 mg/kg soil for acid, neutral and sodic soil respectively) and Mn (4.4-5.03, 2.15-4.02 and 3.08- 4.5 mg/kg soil respectively) was increasing initially and then started to decrease with time. Micronutrient Zn was increasing (8.76-11.15, 7.85-10.10, 2.86-5.45 mg/kg soil for acid, neutral and sodic soil respectively) throughout the duration, whereas soil available Cu content decreased steadily (1.87-1.10, 1.59-0.99, 1.46-0.93 mg/kg for acid, neutral and sodic soil respectively). All the micronutrient was well correlated to changes in soil pH and OC. However their strength varied in terms of soil type and micronutrient in consideration. Keywords Organic amendments, Plant available Micronutrients, Soils of India, Soil reaction, Soil organic carbon, Incubation study Accepted: 18 April 2018 Available Online: 10 May 2018 Article Info