Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 7, 2007
Publication Date: February 1, 2008
Citation: Caesar, T., Caesar, A.J., Gaskin, J.F., Sainju, U.M., Stevens, W.B. 2008. Ecology and function of culturable microbes in soil aggregation. In: Tian-Xiao Liu, editor. Soil Ecology Research Developments. Hauppauge, NY:2007 Science Publishers, Inc. p. 121-138. Interpretive Summary: While there is a relative abundance of studies descriptive of soil aggregation, there is currently a paucity of research concerned with the taxonomic diversity of functional bacteria involved in soil aggregation. Knowledge of the microbiology of soil aggregation can perhaps be informed by some major findings and studies in microbial adhesion and biofilm formation, which are described in this review. Because cause-and-effect investigation of the role of specific bacteria in the important issue of soil aggregation is highly constrained without cultural methods, this review examine the need for studies with cultures detected at the highest levels of abundance in soil aggregates through isolation onto low nutrient or selective media, identification of these cultures and assessing them for traits possibly related to soil aggregation such as EPS production and further, the development and application of assays to test their ability to cause water stable soil aggregates, and will attempt to pinpoint strategies for future research.
Technical Abstract: Soil structure plays a dominant role in the physical protection of soil organic matter by controlling microbial access to substrate, microbial turnover processes, and food web interactions. Good soil structure results in soil productivity, a cornerstone of agricultural sustainability. While there is a wealth of knowledge about soil aggregation, soil microbial biomass and microbial diversity of soil, there is little knowledge of the microbial community ecology of soil aggregates. This review intends to expand upon and examine the microbial nature of soil aggregation: species causal to aggregation and functional groups involved. One focal point will be to examine how a quest for identifying and characterizing key species associated with microaggregates can have implications for management practices to improve soil aggregation and ultimately soil structure. The review will attempt to identify some promising avenues for future research in this area of soil biology that is a central one to soil quality. Our goals are to catalyze rigorous, innovative research on current approaches and techniques on the microbial ecology of soil aggregation.