Uso de coberturas vegetales como alternativas al control de malezas en plantación de Eucalyptus spp

Sustainable forest production faces the challenge of reducing dependence on synthetic chemical herbicides for weed control, driving the search for alternatives based on cultural control. The objective of this work was to evaluate the effect of different cover crops sown prior to planting on weed infestation in the planting row and the initial growth of Eucalyptus spp. The trial was conducted at the “El Tembetarí” estate, owned by UPM Forestal Oriental S.A., located 3 km south of the 68-kilometer mark of National Route 26 in the Department of Paysandú, Uruguay. The cover crops used consisted of two grass species (Avena strigosa and Lolium multiflorum) and two legumes (Medicago sativa and Lotus corniculatus), with varying sowing densities and species combinations, totaling 13 treatments including an operational control under chemical control. During the evaluation period, dendrometric variables (height, RCD, and crown diameter) and the percentage of crop and weed cover were recorded. The results indicated that cover crops are an effective tool for weed suppression, with a time-dependent suppressive capacity that became significant starting at 66 dpp. Grass and legume mixtures proved to be the most efficient option, with oats being the species with the highest individual contribution to the suppressive effect. However, an early interference for water and nutritional resources was observed, which limited tree growth. By the end of the period, the operational control showed significantly superior development, doubling the dendrometric parameters of the remaining treatments. While cultural control through the use of cover crops entails a biological cost in the initial growth of the eucalyptus, it represents a viable strategy to move toward more sustainable management systems aligned with international certifications. Future research is recommended to focus on adjusting sowing densities and the timing of cover crop establishment to minimize direct competition with the trees.