Lightweight and compact radiometers for soil moisture measurement: a review

Fresh water is considered to be one of the most precious natural resources in many countries. Given that soil moisture plays a salient role in vegetation growth, the continuous and timely measurement of soil moisture content is critical to manage water shortages, especially in the agriculture sector [1], [2], which is the largest water use sector in Australia. A 10% water savings in the Australian agriculture sector would be equivalent to a reduction of more than 30% of the combined water consumption from Australian capital cities [3]. Further, soil moisture influences the process of rainfall being partitioned into runoff and infiltration, and saturated soil could turn heavy rain into floods. Therefore, soil moisture information is essential for accurate climate forecasting as well as improving flood and drought prediction [3]–[5].