Evaluating tensiometers and moisture sensors for cranberry irrigation
Irrigation scheduling continues to be a major challenge in cranberry (Vaccinium marcrocarpon Ait.) production. Many growers tend to rely on the 25 mm week-1 rule from rain and irrigation despite evidence that in most years, this results in weeks of either inadequate or excessive soil moisture. This project tested wireless tensiometers and farmer practice for irrigation management on six cranberry bogs in southeastern Massachusetts. When a tensiometer was used to decide when to irrigate, irrigation was initiated only when the tension reading was -5 kPa and stopped at -2 kPa. The grower method of 25 mm week-1 was used as control. In each method, volumetric moisture sensor readings were taken and canopy temperatures were continuously monitored. Cranberry plant density and yield components were measured. The results showed that the grower practice had tension readings of -2 kPa or less and was consistently wetter than using the tensiometer method. On average, the volumetric water content of the grower practice was 26%, and 17% with the tensiometer method. Fruit rot was 7% higher and yield was 24% lower under the grower practice relative to the tensiometer method. It is highly likely that irrigation based on detecting available moisture in the soil and irrigating only when the moisture is inadequate to support plant growth results in better cranberry yield and less fruit rot.
Jeranyama, P., DeMoranville, C.J. and Kennedy, C.D. (2017). Evaluating tensiometers and moisture sensors for cranberry irrigation. Acta Hortic. 1180, 369-372
Vaccinium macrocarpon Ait., irrigation, tensiometer