Evaluation of the biological quality of soil in citrus systems using Pfeiffer chromatography

Abstract

This study implemented Pfeiffer chromatography for the analysis of the biological soil quality of areas cultivated with Tahiti lime (Citrus latifolia) in Estelí, Nicaragua by applying agroecological and conventional management. Using a pre- and post-treatment evaluation design, chromas were performed per plot, and morphological patterns were described such as (radial gradient, halo homogeneity, branching, dark precipitates, and center–edge chromatic transition). As a basis, physicochemical analyses were incorporated (organic matter, available phosphorus, cation exchange capacity, and bases) and, as support, eco-physiological measurements in plants (SPAD, pH and °Brix in sap, nutrient concentration, foliar moisture) and productive variables (fruit weight, diameter, and length). The chromas showed greater biological stability in agroecological management (well-defined concentric rings, continuous transition, and smaller precipitate zones), correlated with lower bulk density, higher infiltration, adequate pH and better nutrient use efficiency. Conventional management showed higher levels of organic matter, fruits with greater diameter and weight, with signs of salinization and lower physiological efficiency. The °Brix in sap varied by batch (agroecological higher in one; conventional in another). Chromatography allowed for clear differentiation of the management types and evidenced variations in the process on the biological quality of the soil. The results, when correlated with the rest of the analyses, matched the trends observed in physical and physiological properties, indicating that it is a practical, visual, and economical qualitative tool that complements chemical analyses in agriculture.