Conservation agriculture increases yields and economic returns of potato, forage, and grain systems of the Andes

Authors: BARRERA, VICTOR - National Institute For Agricultural Research (INIAP); Delgado, Jorge; ALWANG, JEFFREY - Virginia Tech; ESCUDERO, LUIS - National Institute For Agricultural Research (INIAP); CARTAGENA, YAMIL - National Institute For Agricultural Research (INIAP); DOMINQUEZ, JUAN - National Institute For Agricultural Research (INIAP); D Adamo, Robert

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2019
Publication Date: 11/1/2019
Citation: Barrera, V., Delgado, J.A., Alwang, J., Escudero, L., Cartagena, Y., Dominquez, J., D Adamo, R.E. 2019. Conservation agriculture increases yields and economic returns of potato, forage, and grain systems of the Andes. Agronomy Journal. 111:2747-2753. https://doi.org//10.2134/agronj2019.04.0280.
DOI: https://doi.org/10.2134/agronj2019.04.0280

Interpretive Summary: Reduced tillage, retention of crop residues, and use of cover crops and nitrogen fertilizer applications are positively associated with yields and profits, demonstrating the economic viability of conservation agriculture in the Andes region of Ecuador. Although Illangama farmers are aware of the environmental benefits of conservation agriculture practices, economic considerations are the main drivers for adopting these practices. The 21% increase in net benefits of using reduced tillage, enhanced groundcover, and application of nitrogen compared to conventional practices can motivate adoption. These conservation agriculture innovations can improve the sustainability of the potato-pasture system and also generate off-farm benefits in the form of reduced erosion (and reduced impacts from erosion on water quality downstream). The study was conducted over 4 years, and the theory of conservation agriculture is that improvements in soil health will foster greater productivity gains over time. However, our study demonstrates the economic viability of conservation agriculture and we recommend that follow-up studies be conducted to study the effects of these viable practices on soil organic matter, macro- and micro-nutrients, and soil health. Cost savings, increased net returns, and better agronomic practices make the conservation agriculture system attractive to farmers in these ecologically vulnerable areas of the Andean region of South America. With limited adaptations, these practices could benefit nearly 200,000 Ecuadorean farms in similar environments, by helping farmers adapt to a changing climate and helping ensure future food security in the region with implementation of more sustainable and economically viable management practices.

Technical Abstract: Physical and environmental vulnerability analysis conducted in 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, inappropriate soil management practices, and frequent fallow periods. Research projects conducted during 2011-2014 adapted and examined the feasibility of conservation agriculture practices for potatoes, barley, bean, and pastures. The practices included surface water deviation ditches, reduced tillage, residue retention, and application of nitrogen, all within an improved rotation. The study examined crop yields, values and overall benefits of alternative practices 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 to 30% and 21% respectively, using a feasible conservation agriculture system compared to conventional practices. It has been documented that, over extended time periods, conservation agriculture increases yields and saves production costs due to less tillage and reduced weeds. Several studies have shown, however, that it takes time for these benefits to emerge, and the delay between adoption and receipt of benefit has slowed the spread of conservation agricultural practices in the developing world. However, our study found that potential benefits in the short term from a conservation agriculture system are possible. This study concludes that conservation agriculture practices are good alternatives even in the short term. The practices should be promoted among Andean producers to increase the productivity and sustainability of their potato-pasture systems.