Conservation Agriculture Increases Profits in an Andean Region of South America

[Abstract:] The Andean region of Ecuador is critical for the country's food security; however, cultivation of high-slope mountainous agricultural systems that experience significant precipitation is accelerating erosion of the soils and reducing the productivity and sustainability of these systems. For 5 yr we monitored tillage and crop residue management practices using a 2 × 2 factorial randomized block (Phase 1) and a 2 × 2 factorial randomized block with split plot (Phase 2) to assess the effects of tillage, crop residue management, and N fertilization on yields and economic returns. Our study found in the initial phase that for three out of the four crops zero tillage (ZT) had higher average yields than minimum tillage, and for one of these three crops, the increase was significant. Our study found in Phase 2 that when N fertilizer was added as a treatment, compared with crops that were not fertilized, yields were significantly higher in four out of five crops. Leaving the crop residue at the surface was a practice that increased the yields of one of the five crops. The higher net economic returns for Phase 1 were with ZT and with harvesting crop residue. When N was added as a treatment in Phase 2, higher net economic returns were found with ZT and residue removed and with N fertilization. Nitrogen fertilizer, crop residue removal, and zero tillage increased net economic returns by 22, 45.1, and 31.8%, respectively. There is potential to use ZT in this region of South America