Wetenschap - 6 juni 1996

Weeping willows make farmers happy

Weeping willows make farmers happy

Using the sprouting trunks of willow trees for land reclamation on riverbanks is an old practice among certain farming communities in upland Bolivia. During the dry season farmers construct a row of tripods in the river bed parallel to the riverbank. One of the three legs of the tripod is a willow trunk (Salix babylonica). When the river flows, these trunks will sprout and the row of tripods is transformed into a living fence of willow trees. The fence breaks the current of the river and thus increases sedimentation. After two to three years the new strip of land is ready for cultivation. This practice enables farmers to increase the area under irrigated cultivation. Bearing in mind the fact that the average landownership is only about half a hectare, an extra plot of a few square metres suitable for irrigation is a considerable acquisition.

Since not all communities in the area use this practice, exchange of local knowledge between communities is an important criterion for the expansion and improvement of local agroforestry systems," says Jeroen van der Horst, WAU forestry student.

Last Thursday, May 31, van der Horst presented the findings of his agroforestry research in a colloquium at the Department of Forestry. Van der Horst spent his practical period in the Potosi region in Southeastern Bolivia and decided to extend his stay to carry out research for his thesis as well. He assessed the dispersion and functions of certain willow and poplar species in two areas in the Potosi region. Besides being used for land reclamation, these tree species provide fodder, timber for construction and for making charangistos, an instrument similar to a guitar. Finally, van der Horst also points to the aesthetic value of trees: trees can make people happy for a number of reasons.