Dry season agriculture in the seasonally flooded lowlands of Tabasco, Mexico: native mején maize in the marceño agroecosystem

The traditional marceño is a dry-season agroecosystem practiced in swamps dominated by popal (Thalia geniculata) in the seasonally flooded lowlands of Tabasco, Mexico. Given the early seasonal dryness and local hydrology, maize farming in the marceño begins in March. This study aimed to evaluate the current local agronomic practices of the marceño in seven municipalities of Tabasco through semi-structured interviews and participatory research. We measured popal and maize plant biomass, described farmers’ seed-selection criteria, and evaluated the farming stages of the agroecosystem. Productivity of the local maize variety mején in swamps (6–8 months of flooding, S plots) and in flooded areas (15–30 days of flooding, F plots) was compared. We analyzed 14 morphological traits of 37 maize cob accessions of mején, criollo, and hybrid maize through cluster analysis. The economic costs of marceño farming were calculated. Popal and mején stubble contributed 19.6 and 8 Mg ha−1 to the soil, respectively. In S plots, mején was ~3.17 m tall and produced its first cob at ~1.9 m, which protected ears from flooding if harvest had not occurred when the wet season began. Productivity in S and F plots was 3.5 and 3.05 Mg ha−1 of dry grain, respectively. Farmers preferred mején for its tolerance to flooding, dough flavor, and overall adaptability. Seed selection relied on a thin rachis (~2 cm in diameter) and ease of shelling. Pre-sowing treatments, two weedings (one while still flooded), and maize sowing followed by reseeding enabled mején seedlings to withstand drought and excess moisture during the highly unpredictable rainy-dry transition. Cluster analysis revealed wide variability and dispersion of morphological traits among municipalities. A framework must be established to design strategies that preserve this highly productive traditional maize system, protect popal-dominated areas, and manage flooding.