This book focuses on sustainability in agriculture and current approaches in plant production. The initial chapter thoroughly examines the history and impacts of Turkey's Soil Protection and Land Use Law (Law No. 5403) and its amendments (Law No. 6537) on protecting agricultural lands and preventing their misuse. It emphasizes preventing land fragmentation, sustainable land management, and relevant legal regulations. The second chapter explores the use of essential oils as natural and eco-friendly alternatives in postharvest fruit preservation, detailing their antifungal effects, positive impacts on fruit quality, and commercial potential. The third chapter discusses the role of hydrogels in enhancing soil moisture under water stress, highlighting their biodegradable and environmentally friendly characteristics in agricultural applications. The final chapter comprehensively investigates resistance mechanisms of walnut (Juglans regia L.) against salinity stress, explaining the physiological and biochemical effects of salt stress, synthesis of osmotic regulators, ion homeostasis, antioxidant enzyme activities, and genetic adaptation processes in walnut. It also covers the role of genetic engineering methods in improving salt tolerance and provides future recommendations. Overall, the book provides a wide-ranging perspective from land protection and natural preservation to stress management and genetic improvement, offering scientific and practical solutions for sustainable agriculture.