ASA Southern Branch 2008 Annual Meeting
February 3-5, 2008
Dallas, TX
Sunday, February 3, 2008
Effect of Organic Production Systems on Arylsulfatase Activities.
Terrence G. Gardner and Zachary N. Senwo. Natural Resources and Environmental Sciences, Alabama A&M University, Po Box 1208, Normal, 35762
Sulfur (S) is an essential macro-nutrient for all organisms including plants. The range of biological compounds that contain S is vast. In particular, S has important structural and catalytic functions for proteins. Recently, deficiencies in S have been reported as being a limiting factor for crop production. The insufficient S supply reported, which can affect the yield and quality of crops, is essentially due to a drastic reduction of SO2 emissions in the atmosphere. Therefore, sulfate is now the primary source of S for plants which take it up from the rhizosphere. However, in soil, over 95% of S is organically bonded. The mineralization of these organic S forms via microbial processes is believed to contribute to the S supply for plants. The enzyme, arylsulfatase is considered a key enzyme implicated in the hydrolysis of ester sulfates, the most labile form of soil organic sulfur. We recently assayed the activity of this enzyme in crop soils under organic production. The method involved the colorimetric determination of p-nitrophenol produced when soils were incubated with p-nitrophenol sulfate, toluene, and acetate buffer at 37o C for an hour. Multivariate statistical analysis data will be presented.