Innovating Traditional Production Systems Through On-Farm Conservation Agriculture and Agroforestry Research

Abstract

Maize (Zea mays L.), the staple crop of Mexico, is often produced by smallholder farmers on sloping terrains. Historically, little agronomic research has been performed under the conditions of these farmers to support them in the sustainable intensification of their production systems. We set up trials at two locations in the state of Oaxaca to evaluate conservation agriculture and agroforestry in collaboration with local farmers. Crop diversification through crop rotations, multicropping, relay cropping or agroforestry increased system yields the most, by up to 1.4 t ha−1 in Teopoxco and 1.7 t ha−1 in Tamazulapam. Increased input use through increased fertilization or liming did not increase profitability enough to justify their use. Zero tillage and residue retention increased yields and reduced production costs. Conservation agriculture with agroforestry was a high-yielding, profitable system that also reduced farmers' risk by providing several harvests per year. The most profitable combinations of agroforestry and conservation agriculture could produce up to $4,854 USD ha−1 in Teopoxco and $2,143 USD ha−1 in Tamazulapam, while the control treatments in the same sites and years produced $175 USD ha−1 and $92 USD ha−1 respectively. In several years the main crop failed, while the trees were able to produce due to their different growing season compared to maize. Through adaptive investigation under farmers' conditions, sustainable intensification of traditional production system is possible with low-cost changes that are locally adapted and within farmers' possibilities.

Review of agronomic research on the milpa, the traditional polyculture system of Mesoamerica

“…Given the higher value of squash than maize, organic fertilization earned a higher return on investment. In trials in Oaxaca, several fertilization proposals were evaluated to increase productivity, but fertilization based on soil analysis did not increase yields sufficiently to justify the costs (Fonteyne et al, 2022b). Given the variability in the milpa's response to organic fertilization and its high costs, including transport, more research is required to support farmers' decisions on this subject.…”

“…Molina-Anzures et al ( 2016) evaluated maize, beans, and squash with and without interspersed fruit tree lines and found higher maize yields with trees, which they attributed to the microclimate generated by the trees. The MIAF system can be highly profitable, given the sale of the fruit, while retaining the milpa as a source of food for the farm household (Fonteyne et al, 2022b). However, the system can be complex, especially the pruning and fertilization of fruit trees, so farmers require technical assistance and access to information on system management (Torres Zambrano et al, 2008;Ruiz Mendoza et al, 2012).…”

“…The literature cites workloads of 27 to 401 days per hectare per crop cycle for milpa systems, depending on the management intensity and the length of time a field has been under cultivation (Table 1). The higher values mentioned in the literature are the result of attempts to control weeds with high intensity manual control; as previously mentioned, the workload and cost are not justified by the small yield increase (Cuanalo and Uicab-Couoh, 2005;Fonteyne et al, 2022a;Fonteyne et al, 2022b). In the Mixteca Alta, Oaxaca, manual sowing may require more than 50 hours of work Milpa in Yaxcaba on the Yucatan Pensinsula, Mexico.…”

“…Sańchez Morales and Romero Arenas (2018) report that in Tlaxcala maize yields were slightly higher in monoculture, but profitability and total productivity were higher in the milpa. Fonteyne et al (2022b) showed for an experiment in Oaxaca, Mexico that when economical values of bean and squash yields were taken into account growing milpa was profitable, while this was not necessarily the case when only considering maize. A meta-analysis of 939 observations of polycultures in 126 studies worldwide revealed that polycultures produced 38% more energy and 33% more income than monocultures (Vanloqueren and Baret, 2009).…”

Weed management and tillage effect on rainfed maize production in three agro‐ecologies in Mexico

“…Conservation agriculture-a production system based on minimum tillage, permanent soil cover with residues or living crops, and cropping diversification-has been promoted to reduce soil degradation (Steward et al, 2018;Wall et al, 2020), but must be adapted to local conditions (Williams et al, 2018). Conservation agriculture has been shown to produce favourable results in Oaxaca, including reduced production costs, higher yields and improved soil health (Fonteyne et al, 2021(Fonteyne et al, , 2022Núñez Peñaloza and Villa Alcántara, 2020;Osorio Alcalá, 2020a). Reduced tillage may go as far as 'zero' tillage-seeding directly into unplowed soil and crop residues-but in severely degraded or hard-setting soils, some tillage in the seeding zone may be necessary.…”