Effect of Soil Compaction and Organic Matter Application on some Soil Biological Characteristic under Wheat Cultivation in Greenhouse Conditions

Soil compaction is a worldwide environmental problem. Investigations on soil compaction have focused mainly on its effects on soil physical parameters and plant growth. There is an essential need to identify the effect of soil compaction on soil organisms and biological process, especially in arid and semiarid regions such as Iran. The main objective of this research was to investigate the effect of soil compaction and organic matter on soil respiration and microbial biomass carbon, urease activity, and soil nitrification. Therefore, a factorial experiment was conducted based on completely randomized design with three replications in greenhouse conditions. Treatments included different compaction levels (0, 10, and 20 %) and organic matter addition (0 and 2 %W/W from the bagasse compost). The results indicated that the effects of soil compaction and organic matter on soil respiration, microbial biomass carbon, urease activity, and soil nitrification rate were significant. Also, the interaction effect of soil compaction and organic matter on the measured biological properties were significant (p<0.01). Furthermore, the results showed that the value of all measured biological properties decreased with increasing soil compaction, whereas, increasing soil organic matter improved those properties and the amount of microbial respiration, microbial biomass carbon, urease activity and soil nitrification significantly increased. Therefore, increasing organic matter or plant residues is an important management approach that can improve soil characteristics and performance.