A Review of Modern Soil pH Monitoring Techniques and Their Effects on Crop Yield

Soil pH is a fundamental determinant of soil fertility, nutrient availability, and crop productivity. It influences chemical equilibria, microbial processes, and plant nutrient uptake, making it a key factor in sustainable agricultural management. Conventional soil pH measurement techniques, such as laboratory-based glass electrode methods, although accurate, are often labor-intensive, time-consuming, and inadequate for capturing spatial variability within fields. With the advancement of precision agriculture, modern soil pH monitoring technologies have emerged, offering real-time, high-resolution, and site-specific data. This review comprehensively examines recent developments in soil pH monitoring techniques, including electrochemical sensors, optical and spectroscopic approaches, proximal and remote sensing, and IoT-based systems integrated with machine learning algorithms. These technologies have significantly improved the efficiency of soil monitoring, enabling farmers to optimize nutrient management and enhance crop yield. The integration of artificial intelligence and wireless sensor networks has further facilitated predictive modeling and automated decision-making. The relationship between soil pH and crop yield is critically analyzed through multiple case studies, demonstrating how precise pH management can enhance nutrient use efficiency, reduce environmental impacts, and increase productivity. Despite these advancements, challenges such as sensor calibration, cost constraints, and environmental variability persist. Future prospects include the development of low-cost sensors, AI-driven decision support systems, and fully automated smart farming solutions. This review highlights the transformative role of modern soil pH monitoring in achieving sustainable agriculture and global food security.