Effects of different nitrogen doses and bacteria application on yi̇eld and yi̇eld components in some peanut (arachishypogaea L.) culti̇vars

This study was conducted under the climatic conditions of Diyarbakır province during the 2021 and 2022 growing seasons, using the Halisbey and Sultan peanut varieties. The effects of different nitrogen doses and Rhizobium trifolii bacterial inoculation on certain agronomic and technological traits were analyzed. The research was designed in a randomized block design with split plots and three replications; the main plots were assigned to bacterial inoculation and fertilizer treatments, while the subplots were assigned to the peanut varieties. The results revealed that key yield parameters such as the number of seeds per plant, stem weight, seed weight per plant, hundred-seed weight, seed yield, oil content, and protein content were significantly influenced by the year, fertilizer dose, variety, and their interactions. Notably, the application of 5 kg/da nitrogen was identified as the most effective dose, resulting in the highest values for several traits including plant height, seed number, seed yield, hundred-seed weight, and oil content. The highest protein content was recorded at 15.68% with 10 kg/da nitrogen application, whereas the highest oil content, 55.86%, was achieved with 5 kg/da nitrogen application. Additionally, bacterial inoculation with Rhizobium trifolii positively affected protein content across all nitrogen levels compared to the control group. These findings demonstrate that low nitrogen doses—especially 5 kg/da— provide optimal outcomes in terms of both yield and quality parameters in peanut cultivation. Compared to higher doses, this approach offers a more sustainable fertilization strategy. Furthermore, bacterial inoculation enhances nitrogen bioavailability, particularly supporting protein synthesis. In conclusion, under the semi-arid climate conditions of Diyarbakır, the careful planning of low-dose nitrogen and Rhizobium applications presents an economically and environmentally advantageous production model for peanut cultivation.