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

Abstract

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. Core Ideas The Andean region of Ecuador is critical for the country's food security. Cultivation of high‐slope mountainous agriculture is accelerating erosion. Conservation agriculture is an attractive management alternative. Implementation of reduced tillage could contribute to higher net income for farmers. These practices could benefit nearly 200,000 Ecuadorean farms.

Soil health management practices and crop productivity

“…No‐till practices, which reduce mechanical soil disturbance to an absolute minimum, can have important economic and environmental benefits (e.g., reduced field operations, reduced erosion, retention of nutrient‐rich top soil, improved water capture and retention) (Delgado et al., 2019; Hobbs et al., 2007; Mosquera et al., 2019), yet the yield impacts of no‐till are nuanced and context dependent, as well as dependent on management duration (Daigh et al., 2018; Nouri et al., 2020). There is evidence of near‐ and long‐term yield reductions with no‐till in some cropping systems (Giller et al., 2015; Pittelkow et al., 2015a; Rusinamhodzi et al., 2011).…”

Potential use of cover crops for soil and water conservation, nutrient management, and climate change adaptation across the tropics

“…With conservation agriculture we may be able to increase economic returns, increase yields, reduce the potential for erosion, and potentially adapt to a changing climate and more frequent extreme events that may lead to increased erosion. Recent studies on conservation agriculture (no-till, crop residue management, and cover crops, with nitrogen [N] fertilizer) have shown that cover crops can contribute to increased yields and economic returns in tropical highlands in an Andean region (Barrera et al, 2019;Delgado et al, 2019).…”

“…The Andean region of South America is a region impacted by cultivation, which is increasing the potential for soil erosion since large areas of the cultivated soils are under slopes that have high erosion potential (Barrera et al, 2019;Delgado et al, 2019;Monar et al, 2013;Figs. 4 and 5).…”

“…4 and 5). This high erosion potential is decreasing the sustainability of these systems and diminishing the potential to achieve food security, especially when farm areas are eroded to the point that the subsoil is exposed or the gravelly parent material may be exposed, significantly reducing soil health and soil quality (Barrera et al, 2019;Chela, 2008;Delgado et al, 2019;Dourojeanni and Jouravlev, 2001;Monar et al, 2013). Fig.…”

“…forage systems of oat/vetch with conservation agriculture could provide an advantage to 200,000 farmers in this region. Barrera et al (2019) conducted a 4-year study to assess the effects of water deviation ditches, reduced tillage, residue retention, and application of a For the treatments with residue (no residue harvested), the product was harvested, and the crop residue was left on the ground, including whole forage that was left in the field (oat-vetch and forage crops with residue). In treatments without residue (residue harvested), the product was harvested and the remaining residue was removed from the plots.…”