Surveys of small farmers in the Bolivian highlands have shown that moisture stress and soil erosion are the two major factors limiting wheat crop productivity. This paper discusses results of the research conducted to increase system water-use efficiency and so help increase productivity. Research began in two highland departments in 1994 to assess the effects of crop residue retention on increasing water infiltration and crop yields. In the Cochabamba high valley, yields consistently have been increased significantly by residue retention, and initial water infiltration rates are considerably higher in plots with ground cover. In contrast, at two sites in Chuquisaca the effects of ground cover have been small or occasionally negative. Direct seeding of wheat into the crop residues was originally undertaken with small single-row ox-drawn no-till seeders brought from Brazil. Although these seed the crop adequately, operator control is difficult. A prototype three-row animal-drawn small grain no-till seeder, therefore, was developed in cooperation with the DFID-funded PROMETA project and the Bolivian research institution, IBTA. Initial results of seeding efficiency and farmer acceptance are positive.
Wall, P.C. Experiences with crop residue cover and direct seeding in the Bolivian highlands. Mountain Research and Development (1999) 19 (4) 313-317.