Effects of a Biological Amendment on Chemical and Biological Properties and Microbial Diversity in Soils Receiving Different Organic Amendments

Microbial amendments have received considerable interest in sustainable agriculture for enhancing crop productivity, improving soil quality, and reducing inputs of chemical fertilizers and pesticides (Hussain et al., 1999). Microbial amendments are also known as biofertilizers, biodynamic fertilizers or microbial inoculants, which are comprised of living microorganisms that can function as chemical fertilizer adjuvants, biocontrol agents, and plant growth factors (Li and Zhang, 2000). One popular microbial amendment is Effective Microorganisms, developed by Teruo Higa, a professor at the University of the Ryukyus, Okinawa (Yamada and Xu, 2000). Effective Microorganisms has been usedas an inoculant to change soil microbial diversity and the microbial interaction between soils and plants, thus Effective Microorganisms has been widely reported to improve soil quality and productivity of crops over a wide range of agroecological conditions. Effective Microorganisms are comprised of a large number of microbial species, predominantly lactic acid bacteria (Lactobacillus plantarum, Streptococcus lactis, and Streptococcus faecalis), numerous typesof photosynthetic bacteria (Rhodoseudomonas spaeroides), actinomycetes (Streptomyces albus), and yeasts (Saccharomyces cerevisiae and Candida utilis) Because most microorganisms in Effective Microorganisms are heterotrophic, they require organic sources of carbon and nitrogen. Thus, Effective Received : 23 January 2007 Accepted : 20 April 2007 *Corresponding author: Phone : +15738845070, E-mail : [email protected] Article