Visions from Above
California is the leading agricultural producer and exporter in the U.S. More than half of the nation's fruits, nuts, and vegetables are grown in the state. Many California farmers rely on information from satellites to determine when to plant their crops, to estimate crop yields, and to react to weather conditions. Satellite imagery helps farmers make daily decisions regarding how much water is needed, the amount of pesticides and fertilizers to apply, and when to harvest their fields.
Satellites help map individual farms, allowing farmers to precisely record information such as soil moisture, positions of hazardous rocks, and yields. With these maps and GPS receivers, a new generation of farm equipment can tailor the amount of seed or chemicals delivered as the tractor moves through the field. GPS-guided tractors and combines even are steering themselves; they can work in the rain or dark of night and locate their exact position within an inch. This precision helps eliminate overlap when planting, spraying, or harvesting. Through the use of this technology, farmers are able to maximize crop yields, lower costs, and be better stewards of the land.
Scientists are using satellites to record where cows roam and when they eat and sleep. Ranchers can use this information to better manage their herds. Researchers also are experimenting with putting satellites to work as cowboys. A collar whispers electronic versions of the cowboy's "gee" (go right) and "haw" (go left) into the cow's ears. By controlling the cow's movement, the whispered commands act as a virtual fence.
Satellites are used to access global agricultural conditions, help determine trade policy, and predict the amount of world food aid that will be needed. Satellite imagery, combined with tracking rainfall, temperatures, radiation, and evaporation, can accurately predict local yields and worldwide production four to six weeks before harvest.
The Golden State produces 91percent of all the grapes (raisin, table, and wine) grown in the U.S. California wine producers are using satellite imagery to select the best grapes for their wine. The Robert Mondavi Winery partnered with NASA Ames Research Center to analyze factors such as grape ripening rate, disease incidence, and soil drainage to improve the quality of their wine.
Left: Satellites are helping measure the leaf area of the vineyard because leaf area gives an overall predictor of the health of the grapes.
