Farming Food for All
Feeding the planet’s growing population uses huge tracks of farmland. Today, humans use more land for agriculture than anything else.
What Landsat Sees
When you look at a field of soybean plants, it looks green because the pigment in the leaves reflects green light. Healthy soybean leaves also reflect infrared light – light we can’t see. By recording how much infrared light is reflecting off plants, we can measure their health.
Landsat’s instruments can sense wavelengths of infrared light to help farmers see where their crops are healthy or not. The Landsat image on the left show what the crops around Garden City, Kansas look like in natural color – light we can see. The shades of red in the image on the right are where infrared light is reflecting off healthy vegetation.
High reflectance of infrared light is a sign of a healthy plant. Plants absorb blue- and red-light energy to create chlorophyll which reflects infrared light. A plant that is healthy has more chlorophyll and will reflect more infrared than an unhealthy plant.
Landsat’s unique view from space can provide images of plant health of important crops like wheat, soybean, and corn across the United States and around the world.
Changes from Landsat
The Landsat series of satellites has observed the changes in farming practices around the world from clearing forests for farmland to irrigating crops in the middle of the desert.
Far beneath the desert sands of the Wadi As-Sirhan Basin in Saudi Arabia, there are aquifers filled with water dating back to the last Ice Age. This underground water is tapped by drilling wells as far down as a kilometer deep and is used to grow grains, fruits, and vegetables in the desert.
This Landsat 5 image (left) shows this area of the desert back in 1987. The upper left of the image around city shows the only vegetation in the area at that time. By 2012, Landsat 7 observed patterns of irrigated farm fields.
New vegetation appears bright green while dry vegetation or fallow fields appear rust colored. Dry, barren surfaces (mostly desert) are pink and yellow. Each green dot is a field watered by a center-pivot irrigation system.
The circle patterns reveal how the farmers water their crops. Large sprinkler systems, like this one, irrigate fields rotating around a center point create circular fields.
How Change Impacts Us
Supplying water to growing crops is one of the most important ways humans use water and accounts for 80 percent of fresh water use across the United States. By giving farmers better data on how their plants are using the water and how much they need, Landsat can help farmers reduce the amount of water they use and harvest more with same amount.
When a farmer irrigates a field, some of that water evaporates from the soil and some transpires from plants' leaves into the atmosphere. These two processes together are called evapotranspiration.
Landsat can measure evapotranspiration by detecting the temperature of the land surface. Farm fields that are consuming more water appear cooler because evapotranspiring water absorbs energy.
The Landsat image on the left shows green circles of irrigated farms in Idaho. The image on the right is a map of evapotranspiration of the same area on the same day. The blue and bright green colors show where fields are evapotranspiring.
How Landsat is helping transform water management in the American West
Landsat-based evapotranspiration measurements help water managers assess how much water farmers are using. The measurements have even been used to help settle water rights conflicts in court.
Landsat Helps Feed the World
Shortly after Landsat 1 launched in 1972, the data was used to measure how much wheat, corn, and other crops were being grown in the U.S. and around the world.
Food production can change year to year with drought, natural disasters, and even war which all impact the planting and harvesting of crops. Knowing how much food is being grown can also help forecast food supply to ensure there is enough food to feed the growing global population.
The U.S. Department of Agriculture uses Landsat data to track the annual yield for every crop produced. This map of the United States shows the where different crops were planted in 2018.
Monitoring and forecasting crop and rangeland conditions is critical for early warning and response planning in food-insecure areas of the world.
Landsat continues to help make data-driven decisions to produce greater quantities of food as population expands and climate change strains lands and water resources.
People of Landsat: Forrest Hall
Most importantly I think, [the LACIE team] showed that remote sensing data ... could be rapidly processed to identify and measure the area of food crops and real-time, report the monthly changes in crop area, yield and production. – Forrest Hall
1963
Earned B.S. degree in Mechanical Engineering from the University of Texas in Austin, TX.
1963
Joined Johnson Space Center in Houston to work on designing such things as docking mechanisms for the Gemini and Apollo missions and landing gear for the Lunar Excursion Module that landed astronauts safely on the lunar surface.
1968
Earned M.S. degree in physics from the University of Houston.
1970
Earned Ph.D. degree in physics from the University of Houston.
1974-1978
Served as Project Scientists on the Large Area Crop Inventory Experiment (LACIE)
1985
Joined NASA Goddard to continue his remote sensing work, using it to aid in the study of the Earth’s climate and the effects humans are having on it.
1992 - 1996
Served as member of the Landsat Science Working Group.
2009
Received the William T. Pecora Award for his instrumental work in advancing remote sensing of Earth and research that contributed to solving a number of crucial problems in remote-sensing science concerned with interpreting images gathered over vegetated areas.
Postcards from Camp Landsat
This week we travel to the Amazon forests of South America. This August 2000 image shows dramatic deforestation in Bolivia. Loggers have cut long paths into the forest, while ranchers have cleared large blocks for their herds. Unique star patterns are formed where clear-cutting for fields and farms fan out from settlements at the center. Healthy vegetation appears orange and cleared areas appear teal in this image.
Collect all five postcards from Camp Landsat continuing with Week 3: Farms & Food !
The adventure continues at Camp Landsat with lots of fun and fascinating Landsat facts and activities.
