WASHINGTON - Farmers know a good weather forecast is essential. Now, long-range outlooks a whole season ahead have been shown to help African farmers do better.
Farmers in Zimbabwe who attended meetings to learn how the forecasts were made and then used those outlooks in making their planting decisions did better in both dry and normal seasons, according to a study in Tuesday's issue of Proceedings of the
National Academy of Sciences.
A team of researchers led by Anthony Pratt of Boston University used long-range outlooks for the Pacific Ocean phenomenon known as El Nino to prepare forecasts for four groups of farmers in the sub-Saharan African country. Zimbabwe is known to suffer unusually dry seasons in years when the El Nino occurs, altering wind and weather movements.
In the Southern Hemisphere summer of 2002-2003 a mild El Nino was occurring and the researchers forecast the likelihood of below-normal moisture for the region. In the summer of 2003-2004 there was no El Nino and the forecast was for normal rainfall to occur.
Their main growing runs from October through March, and the forecasts for the period were made in September.
Of 367 farmers briefed on the forecasts, 57 percent reported making changes in their planting decisions because of what the scientists told them.
Facing the forecast of drought, some decided to plant early to take advantage of rains and to give themselves the opportunity to replant later if need be. Others changed the variety of crops to plant.
In the summer when normal rain was forecast, farmers tended to plant a greater proportion of their land rather than holding back some, which they often do in years when they do not know what to expect.
Farmers who made changes based on the forecasts reported an increase in harvest of 18.7 percent in the wet year and, even in the dry year, a slight increase, 0.3 percent.
"It appears that the forecasts benefit farmers the most when they give them the opportunity to take advantage of good conditions," Pratt and his co-authors reported.
The research was done in the villages of Tiya and Mhakwe where the staple crop is corn and the villages of Mafa and Mokoka where farmers plant a mixture of corn, sorghum and millet.
The research was funded by U.S. National Oceanic and Atmospheric Administration Program on the Human Dimensions of Global Change.
NOAA's
National Weather Service issues long-term forecasts for the United States, which is much larger, and has a much more varied weather pattern, than Zimbabwe.
Brad Rippey, a meteorologist at the U.S.
Department of Agriculture, said El Nino conditions can also affect the United States, especially the Southern cotton belt. However, it is only one of many factors affecting the weather here.
Many U.S. farmers are aware of the long-range forecasts, he said, but he was unsure how much they use them.AP
