This book explores integrated approaches to sustainable agriculture in the context of climate change, urbanization, and global food security challenges. It compiles findings from five interrelated research studies, each focusing on a critical component of agricultural sustainability. The first study analyzes spatial and temporal trends in grain sown areas and output across Jiangsu Province, China (2010-2022), highlighting the impact of land use, urbanization, and resource efficiency. The second employs ARIMA (Autoregressive integrated moving average) modeling to forecast trends in cultivated land, fertilizer use, and rice and wheat production through 2035, offering predictive insights for agricultural policy. The third and fourth studies evaluate nutrient uptake efficiencies of green manure crops--both non-leguminous (e.g., forage radish) and leguminous species (e.g., pea, chickpea)--under varying fertilizer and rice straw incorporation treatments. The book features quantitative data, comparative charts, and soil-enzyme analyses, offering scientific evidence for enhancing crop productivity, soil fertility, and environmental sustainability. Researchers, agronomists, and policy planners will benefit from its data-driven strategies for optimizing nutrient use and land management. Its unique combination of field experiments, statistical modeling, and sustainable practices makes it a practical guide for advancing resilient agricultural systems.