Effects of Decomposing Maize Litter on Community Level Physiological Profiles of Soil Bacteria

Abstract

Microbial biomass, basal respiration, and community level physiological profiles (CLPP) based on substrate utilization were studied during the decomposition of maize litter under different simulated soil management systems. Laboratory experiments were conducted on agricultural soil samples from Denmark, Germany, and Italy. Maize litter was either placed on soil surface (mulched) or mixed into soil (incorporated) to simulate two soil management types: tillage and no-tillage. Control samples lacking maize litter were also investigated. All soil samples were incubated at 14°C for 52 weeks. Microbial parameters were assessed after 2, 4, 8, 16, 32, and 52 weeks of incubation. During incubation, we found a significant decrease in microbial biomass C in the soils amended with litter. For all treatment types, there was a clear shift in the CLPP during decomposition; during incubation, the relative utilization of carbohydrates decreased and the usage of amino acids increased respectively. After 52 weeks of incubation, the CLPP from all treatment types were very similar.