ARS | Publication request: THE EFFECT OF SOIL ORGANIC AMENDMENTS AND A BIOLOGICAL FERTILIZER (EM) ON FUNCTIONAL DIVERSITY OF A WHOLE-SOIL MICROBIAL COMMUNITY

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 24, 2003
Publication Date: November 2, 2003
Citation: PARK, K., KREMER, R.J. THE EFFECT OF SOIL ORGANIC AMENDMENTS AND A BIOLOGICAL FERTILIZER (EM) ON FUNCTIONAL DIVERSITY OF A WHOLE-SOIL MICROBIAL COMMUNITY. AGRONOMY ABSTRACTS. 2003. CD-ROM (UNPAGINATED). AMERICAN SOCIETY OF AGRONOMY. MADISON, WI.

Technical Abstract: Organic matter sources and biological fertilizers can change functional diversity of soil microorganisms. Organic amendments and cover crops were studied for effects on soil microbial diversity. BIOLOG assays for soil bacterial carbon use were used to compare physiological activities of soil microbial communities. Soil treatments including cover crops (oats, red clover), municipal compost, poultry litter, and biological fertilizer (EM) were imposed on a Mexico silt loam (fine, montmorillonitic, mesic Mollic Endoaqualf). Soils sampled periodically in 2001-2002 were assayed using BIOLOG GN plates. Principal component analysis (PCA) was applied to absorption (570 nm) and average well color development values based on sample date or pooled by year. Principal components (PC) 1 and 2 explained 30-38% and 8- 9% of total variation, respectively. PCA detected seasonal changes in both years, yet functional diversity in autumn samples recovered to the initial ordination of April samples. Only poultry litter affected functional diversity when analyzed with total data over both years. Variables selected with stepwise discriminant analysis separated organic and biological fertilizer treatments from untreated control. The number of variables selected with the biological fertilizer was less than those selected with other organic amendments. Treatments with organic amendments and biological fertilizers may affect functional diversity but cannot overcome environmental or seasonal effects.