Correlation between the Soil Moisture Reading Obtained with Soil Moisture Sensors and Gravimetric Method for Scheduling of Irrigation in Maize

Abstract

A field experiment was conducted at Water Technology Centre farm (WTC), College of Agriculture, Rajendranagar, Hyderabad for studying the correlation between the soil moisture reading obtained with soil moisture sensors and gravimetric method. The experiment was designed in split plot with two main treatments comprising of surface furrow (M1) and drip irrigation (M2) methods and six irrigation schedules were assigned to sub treatments and replicated thrice. Significantly higher grain yield (7.05 t ha-1) of maize was observed with nano sensor (IITB) based irrigation scheduling over rest of the irrigation schedules except gypsum block. The results revealed that correlation between the tensiometer readings and gravimetric moisture content showed a negative non significant correlation before irrigation in surface furrow irrigation method and negative significant correlation for drip irrigation method. But in case of after irrigation a positive non significant correlation was observed in both drip and surface furrow irrigation methods. The gypsum block reading and gravimetric moisture content studies showed a negative significant correlation before irrigation in both surface furrow and drip irrigation methods, where as a positive non significant correlation between gypsum block readings and gravimetric moisture content readings were noticed after irrigation in both drip and surface furrow irrigation methods. Similar trend was recorded in nano sensor, except that it showed a positive significant correlation in both irrigation methods before irrigation. The correlation studies between the profile probe readings and gravimetric moisture content showed a negative significant correlation in surface furrow irrigation method at before and after irrigation, whereas, a positive significant correlation was observed after irrigation in drip irrigation method.