Soil Moisture Sensor-Based Irrigation Reduces Water Use and Nutrient Leaching in a Commercial Nursery

Abstract

Significance to Industry: High quality irrigation water is becoming increasingly scarce and it is becoming more important to use the available water efficiently. One approach to more efficient irrigation is the use of soil moisture sensors to control irrigation. Soil moisture sensors can detect when the substrate water content drops below a growerdefined set point and can be used to automatically turn on the irrigation when needed. Using this approach on a hydrangea crop in a commercial nursery from May 6 – July 23, 2008 resulted in large water savings: plots irrigated using standard irrigation practices used 133,000 gallons during this period, as compared to only 23,300 gallons for plots with soil moisture sensor-controlled irrigation. Excessive irrigation in the control plots also resulted in more nutrient leaching: on June 13, substrate EC in control plots was 0.94 mS/cm, while substrate EC in soil moisture sensors-controlled plots was 1.51 mS/cm. Thus, soil moisture sensors are a highly effective tool for reducing both water use and nutrient leaching.