Big Island Gets New Soil-Weather Stations

“Hawai`i has lots and lots of rain gages and rainfall data, but very little information on soil moisture,” says Chris Jasper, NRCS Soil Survey Project Leader in Kealakekua.  But rain gages and rainfall data only tell half the story. It is usable soil moisture that really matters to crops and native plants.  Usable soil moisture can be very different than annual rainfall because of the variations in soil type and evapotranspiration, Jasper goes on to explain.  “That’s why I started working on a project proposal to start actually measuring soil moisture.”  His efforts are now bearing fruit thanks to a partnership with the National Water and Climate Center (NWCC) Soil Climate Analysis Network (SCAN)  program headquartered in Portland, Oregon.  SCAN is a national initiative to measure soil moisture and other climate factors in rural areas.

The partnership has resulted in the installation of eight soil-weather stations on the Island of Hawaii.  Luckily, SCAN program objectives fit nicely with Jasper’s need for soil moisture information and his plan for strategically placing instruments around the island to best gather data, “I was ecstatic that they were willing to fund about 98 percent of the cost of my proposal and bring in world class installation expertise,” Jasper recalls.

Last year, over a ton of equipment was used by the NRCS Kealakekua-based team to assemble the eight soil moisture stations across the Island of Hawaii at Waimea Plain, Kemole Gulch, Kainaliu, Silver Sword, Pua Akala, Maria House, Island Dairy, and Kukuihaeli.  “I picked these sites so that the data will answer the most questions possible,” said Jasper.

Five of the sites include full weather stations, three sites measure soil properties only. All eight sites are linked to the internet via radio signals sent hourly.  The data from these sites is hosted by the National Water and Climate Center website.  “The website contains the current and historical data for each site, all of the soil pedon information, a site description, and a ‘hot link’ to the National Soil Survey Center Laboratory database, which contains all of the site characterization (chemical, physical, and mineralogical) information,” according to NWCC leader, Garry Schaefer.

Access to the data is free and available to the public to view or download on the NWCC SCAN page.  “Now that we have a years worth of data it is starting to be really useful,” suggests Jasper. NRCS staff could use the data in any number of ways.  The live weather data can be used for planning daily activities and the historical data can be downloaded and used.  Case Kea, the dairy manager who hosts one of the full weather station sites says he can log on to the web site from his home in Hilo 20 miles from the farm and check the wind speed and direction before he decides if it is a good day to apply liquid manure.  With a $4,000 per month electric bill he also plans to use the historical sunshine and wind velocity data to explore the feasibility of wind or electric power on the farm.
Your contact is Jolene Lau, NRCS public affairs specialist, at 808-541-2600, ext.135.