Vetiver Grass Fights Soil Erosion

Vetiver grass, also known as khus, has great potential for subsistence farming on hills in drought-prone areas of the developing world. Over the last three years, World Bank agricultural advisor John Greenfield has experimented with this hardy, deep-rooted and thick-tufted variety of grass on 40,000 acres of rainfed farmland in India. Although use of grasses and trees has long been crucial to soil conservation strategies, khus has advantages that other plants do not. It is cheap and requires little water once established. It is deep-rooted. It is not self-germinating and thus will not spread and become a weed. In addition, it is avoided by goats and cows, enabling it to be planted on unfenced farmland. When used in combination with such advanced methods as contour farming, it achieves maximum results.

Planting of grass strips is a cheap alternative to earthen embankment soil conservation strategies. Embankments are effective but require great investments of labor and time to erect; Third World farmers are not trained as engineers. Vetiver grass, planted in rows across the contour of fields, anchors the soil with roots that reach almost 10 feet into the ground. Rainwater flowing down the slope is slowed by the grasses, and soil particles are deposited as the water slows down. The grass, which takes several years to become fully established, has been used to prevent soil erosion in Fiji and the West Indies, and the recent Indian experience has convinced many local experts of its value. Experimental results showed a 200-to 300 percent increase in crop yields in the southern state of Andhra Pradesh. While the best results will be achieved with high yield practices, the use of erosion control will prove beneficial to most farmers.

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John Greenfield
World Bank
55 Lodi Estate
New Delhi 3