Every day - up to thirty times a day, in fact - one of Mark Mason's employees at Nature's Reward Farms in Monterey County, California brings him the results of a soil test for discussion.
Mason supervises fertilizer and irrigation for the farm's 5,000 acres along California's Central Coast, which is nicknamed "America's Salad Bowl" and is one of the most productive and diverse agricultural regions in the world. Those soil test results are key inputs for one of his newest tools: CropManage, which is operated by the University of California Cooperative Extension and uses data from NASA and other sources to create customized irrigation and fertilizer recommendations. In addition to satellite measurements of crop development, it gauges local weather, soil characteristics, and irrigation system efficiency.
But central California doesn't get much rain. Most of the Central Valley's water comes from streams and reservoirs that capture mountain snowmelt and groundwater stored in porous deposits deep below the surface. These water sources face increasing pressures due to climate change, human use and natural variability, making water management a complex and evolving issue. Monitoring how much water is available to grow our groceries has never been more vital, and NASA's Earth-observing satellites and partnership programs help farmers, water resource managers and policymakers monitor and allocate increasingly scarce water resources throughout their state.
NASA researchers closely observe central California's water sources, how they're changing over time, and why - and produce information that can be used to determine what to do about it. Satellites, airborne and field missions track snowfall, rainfall, soil moisture levels, groundwater depletion, crop health and evapotranspiration. By providing better information on the quantity of water entering and leaving the system these indicators help farmers determine how much water they will need and how much will be accessible.
Matt Rodell is the associate deputy director of Earth sciences for hydrosphere, biosphere, and geophysics at NASA's Goddard Space Flight Center in Greenbelt, Maryland. He studies groundwater around the world, using data from NASA's Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission. Groundwater is especially important in places like the Central Valley and Central Coast that don't get much precipitation and face frequent droughts.
"Groundwater is hugely important because it's typically always available," Rodell said. "It's stored up over many years, or decades, or centuries, or millennia - it's like your savings account. You always want to have that water set aside so it's there for hard times." California is one of the global hotspots GRACE researchers are studying. It's one of many areas where groundwater is being depleted more quickly than it's being recharged.
Read the complete article at www.spaceref.com.