Restricciones edáficas en suelos cacaoteros de la Amazonía peruana

Introduction. District-level soil assessments may obscure local constraints relevant to cacao soil management. Objective. To characterize and prioritize environmental edaphic constraints in cacao soils of the Peruvian Amazon, with emphasis on soil acidity, available phosphorus, aluminum saturation, and available cadmium at the locality scale. Materials and methods. A total of 1,842 surface soil samples (0–20 cm), collected between April and July 2021 in 84 localities in the districts of Puerto Bermúdez and Constitución, were analyzed. Physical and chemical soil variables were evaluated using descriptive statistics, district-level comparisons, locality-level summaries, co-occurrence analysis, bivariate relationships, principal component analysis, and exploratory clustering. Results. Median soil pH was 4.65, median available phosphorus was 5.27 mg kg⁻¹, and median aluminum saturation was 39.21% (1,539 valid determinations). The co-occurrence of pH below 5.5, available phosphorus below 7 mg kg⁻¹, and aluminum saturation of at least 30% was observed in 757 samples (41.1%), indicating the combined occurrence of acidity, low phosphorus, and high aluminum saturation. Available cadmium had a median of 0.035 mg kg⁻¹ but showed a heterogeneous distribution, with localized signals in 13 localities. Conclusions. The locality scale distinguished widespread chemical constraints from localized available-cadmium signals and provided criteria for prioritizing soil monitoring.