Conservation Agriculture Increases Yields and Economic Returns of Potato, Forage, and Grain Systems of the Andes

Physical and environmental vulnerability analysis conducted for the Illangama watershed located in Ecuador's Andean highlands, shows deteriorated soil quality and declining crop productivity. These problems are caused by soil erosion in steep slopes and inappropriate soil management practices. Research projects conducted from 2011 to 2014 adopted and examined the feasibility of conservation agriculture practices for potato (Solanum tuberosum L.), oat (Avena sativa L.) and vetch (Vicia sativa L.), barley (Hordeum vulgare L.), bean (Vicia faba L.), and a mixture of pastures (annual ryegrass [Lolium multiflorum Lam.], perennial ryegrass [L. perenne L.], orchardgrass [Dactylis glomerata L.], white clover[Trifolium repens L.], and red clover [T. pratense L.]). The practices included surface water deviation ditches, reduced tillage, residue retention, and application of N, all within an improved rotation. The study examined crop yields and economic returns in an effort to identify the best practices. Results indicate that crop productivity and net (of cost of production) benefits of the system were increased as much as 25 and 24%, respectively, using a feasible conservation agriculture system compared to conventional practices. This study shows that conservation agriculture increases yields and saves on production costs due to less tillage. We also found that N fertilization with these conservation agriculture practices increases yields and net returns. This study concludes that conservation agriculture practices are good alternatives for these high-altitude Andean soils. The practices should be promoted among Andean producers to increase the productivity and sustainability of their potato-grain-pasture systems.