Issue link: http://winesandvines.uberflip.com/i/643683
WINERY & VINEYARD EQUIPMENT 36 WINES&VINES March 2015 matric potential sensors—one placed near the top of the soil and another at the bottom of the root zone. "You have to have at least two: one shallow and one deep," he said. The deep sensor is vital for knowing when the stored moisture in the soil has been de- pleted and it's time to turn on the irrigation system. He said growers often get caught un- aware by a July heat spike because they don't realize the stored moisture has gone dry. Data from matric potential sensors are a little easier to work with, especially when pre- sented in a graph. The water content or volu- metric capacitance sensors require more interpretation based on soil type, vine perfor- mance and the field capacity of a particular vineyard. "For me, they're a little hard to work with," Grant said. "You have to get a sense of what they mean in your particular vineyard." He said one of his clients who is the most comfortable using the capacitance sensors also records data about evapotranspiration, takes PRODUCT FOCUS Volumetric Soil Moisture Sensors AQUASPY AquaSpy's Vector Probe features 12 sen- sors set at 4-inch intervals. The probe measures moisture content, conductivity and temperature simultaneously but sepa- rately with a quadrature measurement cir- cuit. The probe is connected with a cable to a communications unit that sends data to the company's web application. aquaspy.com CAMPBELL SCIENTIFIC Campbell Scientific's CS650 and CS655 measure water content, conductivity and tem- perature with time domain reflectometry (TDR). The CS650 is an SDI-12 device and has a sensing volume of about 7.5 cm radius around each probe. The sensor does not need to be calibrated for most soils. The CS655 has shorter rods for use in more compact or rocky soils. campbellsci.com SENTEK Sentek's EnviroSCAN probe can hold up to 16 sensors and is designed to work at shallow depths or deep installations up to 131 feet. The company's Drill & Drop probe is designed for easy installation and removal and is 24 or 48 inches long with sensors every 4 inches. sentek.com HSTI HSTI offers the HydraSCOUT and wire- less HydraLINK probes. Both are range in length from 100 mm to 1,500 mm, use the SDI-12 interface and come stan- dard with five sensors that measure moisture and temperature. hsti.co