Effects of drougt and biochar treatments on some morphological and physiological parameters in Turkish hazelnut seedlings

Global climate change, which has emerged with the increasing consumption of fossil fuels since the Industrial Revolution, has caused environmental crises worldwide. Increased temperatures, irregular rainfalls, and extreme weather events, especially on plants, create severe stress factors such as drought, threatening agricultural productivity and ecosystem balance. Drought adversely affects plants' growth, development, and photosynthesis capacity and reduces productivity. Irrigation and fertilization methods are critical in overcoming this concern because these practices improve the resistance of plants to drought by meeting their water balance and nutrient needs. Biochar is obtained by pyrolysis of organic materials in an oxygen-free environment, improving soil health. By increasing the water retention capacity in the soil and improving its physical and chemical properties, biochar significantly contributes to the adaptation of plants to drought conditions and the sustainability of agricultural production. This study investigated the responses of Turkish hazelnut (Corylus colurna) seedlings, one of the important agricultural products of Türkiye, to drought and biochar applications. Our research results have shown that biochar applications positively affect Turkish hazelnut seedlings' growth performance and physiological resistance. In particular, it has been observed that biochar increases the soil's water retention capacity and enables plants to be more resistant to water stress. Increases in photosynthetic activity and chlorophyll content prove that biochar supports plant metabolism. In addition, the increase in proline accumulation in seedlings under drought stress has been interpreted as plants tending to accumulate excessive proline to cope with stress. However, biochar applications have been determined to improve soil properties by increasing organic matter content and moisture. This study emphasizes the importance of biochar in sustainable agricultural practices. It predicts that it can be an effective option in adapting high-economic value agricultural products such as hazelnuts to environmental stress factors such as drought. These findings not only increase the sustainability of agriculture but also provide guidance that can contribute to agricultural sustainability studies on a global scale.