Foliar biofortification with iron, zinc and copper in maize under rainfed climatic conditions and its nutritional quality

Resumen

Objective: To evaluate nutrient absorption and forage quality in corn microsilos (Zea mays L.) cultivated under rainfed conditions and foliar biofortified with iron (Fe), zinc (Zn), and copper (Cu).

Design/Methodology/Approach: The study was carried out at the Juan Rodríguez Clara Higher Technological Institute, located in the municipality of Juan Rodríguez Clara, Veracruz. Foliar applications of Zn, Cu, and Fe were administered throughout the crop's growth cycle. Bromatological parameters and mineral content were analyzed through correlation and interpretation in relation to climatic variables, specifically temperature and precipitation.

Results: Moderate temperatures (22–23 °C) promoted Fe absorption (202 ppm); however, they also led to increases in neutral detergent fiber (NDF) (59%) and acid detergent fiber (ADF) (33%), enhancing plant structural rigidity. Conversely, cumulative rainfall of 200 mm negatively impacted Zn (29 ppm) and Cu (19 ppm) uptake due to leaching and water stress, which subsequently reduced the organic matter content (%OM) in the microsilos to 88%. A positive correlation was identified between Fe concentration and structural fiber content, while a negative correlation was observed between protein levels and hemicellulose, indicating a potential metabolic imbalance.

Study Limitations/Implications: Rainfall interfered with Zn and Cu absorption, underscoring the importance of aligning foliar fertilization strategies with prevailing weather conditions.

Findings/conclusions: Fe biofortification influences plant structure; water stress limits the absorption of Zn and Cu. Foliar applications must be adjusted according to the climate to optimize the nutritional quality of the forage.