Determination of the effect of different organic and inorganic fertilizer applications on yield and soil carbon budget of sorghum and soybean crops under long term field conditions

This study aimed to determine the growth, yield, and carbon-nitrogen content of soil plants and the budgets of soybean and sorghum plants under long-term organic and inorganic fertilizer applications. The research treatments included control (without fertilizer), mineral fertilizer, animal manure, compost, and compost + mycorrhiza. Among the parameters examined throughout the research, data on plant growth, grain yield, stem dry matter; nutrient concentrations and soil properties were analyzed and evaluated. According to the results of the study, the highest grain yield of sorghum was determined in mineral fertilizer treatments with 3815 kg ha-1, while the highest grain yield of soybean was determined in compost treatment with 1460 kg ha-1. According to the effects of treatments on soil organic carbon (OC) content, high organic carbon concentration and carbon sequestration were determined in plots where animal manure was applied. While compost + mycorrhiza application had the highest TOC sequestration statistically with 36.17 Mg ha-1 at 0-15 cm depth in soybean cultivated plot soils, the highest TOC content was determined in animal manure application with 33.10 Mg ha-1 at 15-30 cm depth. In sorghum plots, 35.72 Mg ha-1 and 34.66 Mg ha-1 of barnyard manure had the highest TOC retention at both depths, respectively. In addition, phosphorus and zinc nutrient concentrations were higher in the plots where organic fertilizers were applied. According to the results of the research, it was concluded that organic fertilizer applications can be applied as an alternative to mineral fertilizers for the parameters examined. Keywords: Long Term Organic, Soybean, Sorghum, Plant Nutrition, Soil Organic Carbon