Abstract

A field experiment in north China was conducted to study the effects of land use and soil elements at a moderate concentration on the amounts of various microbial populations, microbial community structure and catabolic activity which were analyzed by cultural method, phospholipid fatty acid (PLFA) and biolog techniques, respectively. The results showed that, land use type might be the primary control on soil microbial community structure. Legumes or soil N was hypothesized as the secondary factor influencing the soil microbial community structure. Legumes played an important role in stimulating the growth and reproduction of various soil microbial populations, accordingly promoting the microbial catabolic activity. Plant diversity had a significant positive effect on the amount of soil bacteria. Soil Cd at moderate concentration had a significant positive effect on microbial biomass. The majority of soil elements at moderate concentration except for Cr had no marked effects on microbial catabolic activity.

Key words: Biolog, land use, microbial biomass, phospholipid fatty acid, soil element.

Abbreviation

AWCD, Average well color development; PLFA, phospholipid fatty acid; MPN, most probable number; FAME, fatty acid methyl esters.