use of the minerals and organic sediments of Río Arque which are freed by rains in the upper part of the river basin. These materials are trapped by altering the course of the river in the Capinota basin to flood some of the fields along the river bed. To alter the course of the river, bocatomas are made, man-made openings or inlets, which have to be rebuilt after each flooding by the river, which is done every 1–3 years. These bocatomas are 30 cm high and capture an average layer of sediment of 10 cm in every field. Building these 'dykes' around the fields is mainly done in December at the beginning of the rainy season. Between the outer dykes and inside the fields, small canals 35 cm deep and 80 cm wide are built to distribute the water equally. At the lower end of the field furrows drain the excess water, so that the land inside the outer dykes is covered by 12 to 15 cm of water. Lameo irrigation and sedimentation at Capinota cover 228 ha and more than 200 farmers participate in it. It enables the farmers to practise an intensive and market oriented agriculture where mainly potatoes and Dutch tomatoes are grown. In fields located further away from the river, the soil is enriched by mixing the river sediments with the existing soil, adding chicken manure. From studies of geomorphology and sedimentation in the Valle Alto region it can be estimated that the technique of lameo goes back as far as 1500 BCE. References External links Province Capinota homepage Sources Lameo, an indigenous method of soil conservation Estimating spatial patterns of soil erosion and deposition in the Andean region Appropriate designs and appropriating irrigation systems Populated places in Cochabamba Department