Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/25/2013
Publication Date: 11/16/2013
Citation: Cook, K.L., Sistani, K.R. 2013. Affect of soil amendments and manure application on nitrifiers and denitrifiers. ASA-CSSA-SSSA Annual Meeting Abstracts. Abstract. Interpretive Summary:
Technical Abstract: Organisms involved in N cycling are particularly important as drivers of ecosystem processes (i.e., N availability, C cycling, methane consumption, GHG production) and as a group they are often the most sensitive to management and climate fluctuations. Despite the importance of the soil microbiota to nutrient transformation and chemical cycling, physio-chemical properties rather than biological properties of soils are traditionally used as measures of environmental status. In general, much is unknown regarding the effect of management methods (i.e., application method, nitrification inhibitors, etc) on important functional groups in soils systems. It is only recently that it has been possible, through application of sophisticated molecular microbiological methods, to sensitively and specifically target important microbial populations that contribute to nutrient cycling and plant health present at the field-scale and in differentially managed soil systems. In this study, quantitative, real-time PCR (qPCR) was used to quantify nitrifiying bacteria and archaea and denitrifiers (narG) in soils planted with no-till corn (Zea mays L.). Nine different N fertilizer sources were evaluated: urea (U), urea-ammonium nitrate (UAN), ammonium nitrate (NH4NO3), poultry litter, and commercially available, enhanced-efficiency N fertilizers including: polymer-coated urea (ESN), SuperU, UAN + AgrotainPlus, and poultry litter + AgrotainPlus. Results show that concentrations of bacteria were high in all treatments with applied slurry (2.9 ± 1.4 X 10e9 cells per gram of soil); about 25% higher than in controls with no slurry added. Concentrations of methanogens and denitrifiers were slightly higher (around 50%) when slurry was applied by injection or aeration (5.3 ± 2.4 X 10e7 cells and 2.8 ± 1.8 X 107 cells per gram of soil, respectively) as compared to no till (2.4 ± 1.6 X 10e7 cells and 1.6 ± 1.0 X 107 cells per gram of soil, respectively).