Soil pH Sensing Techniques and Technologies-A Review

This paper presents the review on different concepts of soil pH detection techniques and technologies. Soil pH is a key parameter for crop productivity therefore its spatial variation should be adequately addressed to improve precision agriculture management system. Soil pH affects the soil's physical, chemical, and biological properties and processes, and thus plant growth. Soil pH, a measure of hydronium ion (H+) concentration traditionally tested in labs to decide how much fertilizer to apply to a field. Recently, with increased emphasis on precision agriculture, economics, and the environment, soil tests are also a logical tool to determine areas where adequate or excessive fertilization has taken place. In addition, they are used to monitor the impact of past fertility practices on changes in a field’s nutrient status. Therefore, developing rapid tools which can detect pH variations on a site-specific basis has become pressing need of the hour because laboratory based methods are inadequate, time consuming, laborious, and expensive. From above perspective, this paper attempts to present review of existing suitable methods, deliberations on pros and cons, and a proposal for pH sensor development which could transmit data wirelessly.