NASA maps soil moisture on a global scale

The initiative is intended to help predict where there will be too much or too little moisture to sustain farming. High-level though it sounds, the data generated from this initiative can be useful for farmers, agricultural organisations, and farm businesses at the ground-level.

The Soil Moisture Active Passive (SMAP) satellite went into operation in early 2015, and has been using radar and radio-wave detection instruments to scan the top 5cm of the planet’s topsoil layer ever since. Photo: NASA

An orbiting soil observatory

The Soil Moisture Active Passive (SMAP) satellite went into operation in early 2015, and has been using radar and radio-wave detection instruments to scan the top 5cm of the planet’s topsoil layer ever since. The data generated from both processes can be combined into detail regional maps identifying areas of severe drought, flooding, and everything in between.

The United States Department of Agriculture (USDA) is now using the data generated through the space programme to supplement its own forecasting techniques – techniques which traditionally make calculations indirectly by comparing regional precipitation and temperature data. All such data is incorporated into maps within Crop Explorer, a programme developed by the American agriculture bureau’s Foreign Agriculture Service, to profile regional crop conditions worldwide.

In an article from NASA’s Jet Propulsion Laboratory, John Bolton, research scientist for NASA’s Goodard Space Flight Centre, says SMAP is designed to address the global need for a wider crop monitoring and forecasting. Variations in global agricultural productivity have tremendous economic, social and humanitarian consequences, says the article, and such data can be used to better monitor and predict these variations.

lliana Mladenova, research assistant with the Goddard Space Flight Centre, says in the same article that the timing of SMAP data-imaging matters as well. “If there’s a short dry period early in the season,” says the article, “it might not have an impact on the total crop yield, but if there’s a prolonged dry spell when the grain should be forming, the crop is less likely to recover.”

The initiative is intended to help predict where there will be too much or too little moisture to sustain farming. Photo: NASA

Useful for researchers, farmers, & others

Soil moisture condition data, along with tools to analyse the data, are also available via Google Earth. Between there and Crop Explorer, anyone can access the latest data and archived historical information – that includes individual farmers.

In an article published by the Canadian Broadcasting Corporation just after the launch of SMAP, Canadian researchers participating in the cross-border initiative SMAP data can “provide early warning of conditions that might lead to an explosion of pests,” such as the canola disease blackleg and grains-targeting blights commonly seen in Canada’s prairie regions.

With such knowledge, farmers can take appropriate (and potentially pre-emptive) actions, such as applying fungicides in areas perceived high-risk areas. Insurance companies, too, might be able to employ the data in risk assessments, when determining who has been affected by drought and floods, and so on.

Continual refinement

SMAP covers the globe every 3 days, providing the USDA and all other users with relatively constant global updates. As the need for more accurate assessment tools increase as a result of shifting agricultural pressures (whether from climate change or other factors), more accurate versions of the now beta-version map viewer will be developed by NASA and its collaborating agencies.