What is the potential impact on carbon storage of the native and introduced tree species commonly associated with coffee in the central Peruvian Amazon? Coffee is a pivotal crop within the Peruvian economy. Nevertheless, the establishment of new plantations—driven by the subsistence needs of smallholder farmers—has led to expansion into forested areas. Given the significance of this crop and the demonstrated ecosystem benefits of agroforestry systems (AFSs), the aim of this study was to evaluate the influence of native and introduced shade tree species on carbon storage in coffee plantations. This study was observational and exhibited characteristics of an unbalanced incomplete block design. Agroforestry systems (AFSs) with shade tree species such as Inga, Retrophyllum rospigliosii, Eucalyptus and Pinus, and three unshaded coffee plantations, were included in this study. The total carbon stored in each AFS was higher than in unshaded coffee plantations. Soil contributed between 47% and 91% to total carbon storage, shade trees (24–46%), coffee (2–7%), leaf litter (0.6–1.9%) and shrubs and herbaceous plants (0.02–0.3%). The AFS with R. rospigliosii achieved the highest carbon storage with 190.38 Mg ha⁻¹, highlighting the compatibility of this species with coffee plantations, as well as its positive effect on climate change mitigation in deforested areas.

Microbial inoculants such as Trichoderma have been proposed as sustainable tools to improve seedling quality in coffee nurseries; however, their effectiveness may vary according to formulation and genotype. This study evaluated three treatments: a solid Trichoderma formulation (1 kg m⁻³ of substrate) based on a multispecies consortium (T. harzianum, T. asperellum, and T. viride; 5 × 10⁹ conidia g⁻¹), a liquid formulation of T. harzianum (1 × 10⁸ CFU mL⁻¹; 1 L m⁻³ of substrate), and a non-inoculated control, using three Coffea arabica varieties (Catimor, Marsellesa, and Gran Colombia) under controlled nursery conditions. A linear mixed model was applied, considering variety and inoculant type as fixed effects and replicates as random effects. The results show that the biostimulant response is strongly modulated by the variety × inoculant interaction. The solid formulation was superior in promoting the expansion of the photosynthetic apparatus, increasing leaf area by 24.6%. In turn, the liquid formulation optimized structural vigor, increasing stem diameter by 17.3% and reducing slenderness by 13.1%. Inoculation reduced the lignification index by 10.4%, favoring dynamic vegetative growth. These improvements were integrated into the Dickson Quality Index, which reached values of 0.41–0.70, greatly exceeding the critical threshold of 0.20 for medium- to high-quality seedlings. It is concluded that Trichoderma acts as a physiological compensator that harmonizes plant architecture, although its efficacy depends on specific compatibility with the genotype, which is essential for ensuring the successful establishment of coffee plants under field conditions.

The exploration and identification of spontaneous weed species in heavy metal–contaminated soils represent a relevant approach for understanding the role and their potential application in phytoremediation. In cacao cultivation, cadmium contamination poses a significant risk due to the restrictions established for soils and cacao-derived products, thereby threatening productive sustainability and export viability. The objective of this study was to identify weed species associated with cacao cultivation exhibiting accumulation patterns and phytoremediation potential for Cd and Pb, through the assessment of biomass production and the bioconcentration factor (BCF) and translocation factor (TF), in natural conditions. Soil samples were collected from seven cacao-growing zones, and the site with the highest Cd concentration (1.65 mg kg⁻¹) was selected, where ten dominant weed species were identified and evaluated. Significant interspecific differences were observed in biomass production and in Cd and Pb concentrations (p < 0.05). Talinum paniculatum exhibited the highest total biomass (6.15 g) and the highest TF for Cd, whereas Cyperus aggregatus showed the greatest total Cd accumulation (2.68 mg kg⁻¹). BCF and TF values enabled the identification of species with accumulation patterns consistent with Cd phytoextraction (T. paniculatum, C. aggregatus, Pseudelephantopus spiralis, Bidens riparia, Euphorbia heterophylla, and Malvastrum coromandelianum) and with phytostabilization (Ocimum campechianum). For Pb the observed patterns were consistent with potential phytoextractive behavior in B. riparia, P. spiralis, E. heterophylla, Hilleria latifolia, and Acalypha stachyura. Although these results do not constitute functional evidence of remediation, they describe heavy metal accumulation and translocation patterns in native weed species, providing a technical basis for the design of future experimental trials aimed at the sustainable remediation of contaminated soils.