such as planting fruit trees or sowing strips of native grass along land contours of the cultivated land. Notable improvements in sediment amounts were seen when farmers adopted certain conservation practices. For example, when the Indonesian rambutan plantation that had been intercropped with cassava was replaced with grass for livestock, the annual sediment dropped from 13.1 Mg per hectare per year to 2.7 Mg. Similarly, farmers in Laos reduced sediment from 5.9 Mg per hectare per year to 0.1 Mg using a fallow system that increased the land’s recovery time. Incentive to Change Globally, farmers have been slow to adopt erosion reduction techniques. IWMI scientists believe farmers lack sufficient incentive. Scientists are assessing a plan to apportion benefits between upland farmers and hydropower companies operating downstream dams. The idea is that hydropower companies, which have a vested interest in maintaining silt-free reservoirs, would pay farmers to minimize soil erosion. “This region has very high topography and, given the economic boom, they need power,” says Pay Drechsel, theme leader for water quality, health and environment, IWMI. “Many hundreds of dams are being planned.” Using incentives to help reduce pollution from fertilizers and pesticides does not mean paying farmers to use fewer agrochemicals; it requires targeting subsidies more precisely. For example, if dangerous levels of phosphorus were found in an area, it would make sense to remove subsidies on phosphorus-containing chemicals or make them expensive, encouraging farmers to use them sparingly. The International Water Management Institute is a nonprofit scientific organization and one of 15 research centers supported by the Consultative Group on International Agricultural Research (CGIAR). IWMI’s mission is “ improving the management of land and water resources for food, livelihoods and the environment.” The Institute is working with overseas partners to help find ways to reduce the negative impacts of inappropriate land use and enhance water quality and livelihoods.
Above: Farming is a difficult way to earn a living in many countries. (left top) Produce vendors in Jayapura, Indonesia, earn a meager 5,000 rupiahs (57 U.S. cents) a day. (bottom) Seaweed harvester Wayan Suwita makes the equivalent of $1.60 a day. (left center and right top) Natural disasters, such as the 2005 tsunami that devastated fields in Indonesia and drought-induced fires, degrade soil quality for already struggling small farmers. © AP Images (4)