Study on Comparison of Soil Moisture Sensor in an Irrigated Field

Soil moisture sensor is an instrument for making rapid measurements of the soil moisture content in the root zone. It is an essential tool for many applications, including understanding of soil water dynamics, evaluation of agriculture water stress, and validation of soil moisture modeling. Studies have shown that electrical resistance measurements may be used to infer soil moisture content under special circumstances. To establish the efficacy in field, six soil moisture sensors were compared for their performance in producing soil moisture data in an irrigated hybrid mango and guava plantation in Vertisols. The sensors used were: MP406, TDR, Moisture Point, Neutron Probe, Tensiometer, and Watermark. All sensors showed correlations (r² > 0.7) to the neutron probe except the Moisture Point sensor. The MP 406 and TDR estimates of soil water were equal and sometime slightly lower than the neutron probe. The Moisture Point estimates of soil water were substantially lower than the neutron probe, MP406, and TDR. It was found that MP406 and TDR give better response as compared to the other sensors in Vertisols.