Effects of corn origin biomass applications on soil microbial diversity in structural crusted soil

The basis of soil health problems lies in the deterioration of physical, chemical and biological properties, and especially low soil aggregate stability and formation of physical crust due to insufficient organic matter levels are among the major problems. The recycling of plant waste generated during agricultural activities into the soil as organic material is critically important both for ensuring sustainable agriculture and for solving the mentioned problems. For this reason, in the thesis study, various corn-based organic materials were applied to the soil with high clay and lime content, weak structure and physical crust problem in the Selcuk University Faculty of Agriculture- Saricalar Research and Application Farm. In the field trial where corn was planted, (YA) corn green manure, (A) corn residue and (KO) corn residue compost were used separately at doses of 2 and 4 tons/da. The effects of the applications on soil physico-chemical properties and bacterial diversity were examined. The effect of organic materials on bacterial community structure was analyzed by high-throughput sequencing. Generally, residue applications have significantly increased the content of organic matter, nitrogen, and phosphorus in the soil. Green manure, on the other hand, have increased the lime content of the soil but have not sufficiently increased the amount of organic matter. All organic treatments have improved soil aggregate stability compared to the control. The bacterial community structure has changed with residue and green manure compared to other treatments. In alpha diversity analysis, it was found that the application of residue at 2 tons/da had the highest bacterial diversity. The dominant bacterial phyla in all applications are Actinobacteriota, Proteobacteria, and Chloroflexi. It has been found that the physicochemical properties of the soil, especially pH, organic matter, and aggregate stability, play a significant role in shaping the bacterial community structure. In conclusion, this thesis determines that direct application of crop residues improves the physicochemical and biological properties of the soil compared to chemical fertilization.