Agroecological management with intra- and interspecific diversification as an alternative to conventional soil nutrient management in family maize farming

ABSTRACT

In traditional polycultures such as milpas, soil degradation and the loss of agrodiversity, threaten rural food security. Although agroecological management using crop functional and genetic diversity could improve soil fertility and family nutrition, experimental evidence is scarce. We conducted a field experiment in which conventional agricultural management (CON) was compared to an agroecological alternative (AGR), with interspecific and intraspecific diversification factors. We hypothesized that: (1) the higher input of organic matter and the suspension of tillage in AGR plots would improve soil conditions, nutrient content and productivity in maize, and intra-root colonization by mycorrhizal fungi as compared to CON plots; and that (2) these conditions would further improve in AGR management with increased intra- and interspecific diversity, since a diverse plant community in the rhizosphere should enhance microbial activity. AGR increased pH, the soil availability of K, Ca and Mg, K in leaves, and mycorrhizal colonization. Within AGR, diversified treatments temporarily increased NO₃⁻ in the soil. The fixation of nitrogen by additional legumes could have produced this result. We conclude that AGR with interspecific diversification is a viable alternative to CON, since a variety of additional edible plants became available concomitantly with the improvement of mycorrhizal relationships and soil conditions.

KEYWORDS:

• Agrodiversity
• legumes
• milpa
• soil nutrients
• arbuscular mycorrhiza

Availability of Data and Material

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Acknowledgments

We would like to specially thank Frédérique Reverchon and Rocío Vega-Frutis who reviewed early versions of this manuscript, to Salvador González-Arroyo and Marisol González-Arroyo for field assistance, Alicia Fierro-Coronado, Sandra Rocha-Ortíz and Omar Lázaro-Castellanos for their laboratory assistance, to Emily J. Wolfe-Sherrie for the translation of the manuscript and to Ocotepec producers for their help and trust, because without them, this study would not have been possible. We are also grateful to two anonymous reviewers who's suggestions greatly improved this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work is part of the DeMano Project supported by National Problems (CONACyT-80033) and Veracruzano Environmental Fund (Fondo Ambiental Veracruzano F.A.V./006/2016</#AWARD-ID;>). The work was part of a master’s degree funded by a postgraduate scholarship from the National Council of Science and Technology of Mexico (CONACYT (CONACYT-450579);Consejo Nacional de Ciencia y Tecnología [450579,80033];