Contenido de nutrientes, acidez y textura del suelo en áreas degradadas por la minería en el Chocó biogeográfico

Abstract

La minería es una de las actividades económicas que más destruyen ecosistemas en el Chocó biogeográfico, por lo que se requiere conocer los efectos que esta tiene en las condiciones fisicoquímicas del suelo con miras a su restauración. En ese contexto el objetivo del presente estudio fue evaluar los cambios en las condiciones edáficas de áreas degradadas por la minería a cielo abierto con diferente edad sucesional en la región. Para ello se establecieron cinco parcelas permanentes de 625 y 2.500 m2 en áreas con 15 y 30 años de recuperación, respectivamente. Posteriormente, se tomaron muestras compuestas de suelos a 20 cm de profundidad y se determinaron sus contenidos de nutrientes, pH y textura. Se observó que los suelos eran ácidos (pH=4,73), con altos porcentajes de arena, materia orgánica (6,62 %), nitrógeno (N) total (0,34 %), fósforo (P) disponible (28,21 ppm), potasio (K) (0,38 meq/100g) y aluminio (Al) (2,15 meq/100 g), pero con bajas cantidades de calcio (Ca) (2,28 meq/100 g) y magnesio (Mg) (1,37 meq/100 g). La disponibilidad de P y K fue alta en ambas edades sucesionales, en tanto que la materia orgánica, el N total, el Ca, el Mg, la capacidad de intercambio catiónico efectiva (CICE), el Al, y el porcentaje de arena incrementaron con la sucesión, aunque el pH y la arcilla, disminuyeron. En síntesis, se evidenció un incremento en la disponibilidad de arena y nutrientes, pero también un aumento en la acidez y la toxicidad del Al con la sucesión. Asimismo, se constató que la recuperación de las condiciones fisicoquímicas del suelo en minas está condicionada por el efecto de la materia orgánica y la vegetación.

Mining is one of the economic activities that most destroy ecosystems in the biogeographic Chocó, so it is necessary to know the effects it has on the physicochemical conditions of the soil with a view to its restoration. In this context, the objective of this study was to evaluate the changes in the soil conditions of areas degraded by open-cast mining with different successional ages in the region. For this, five permanent plots of 625 and 2,500 m2 were established in areas with 15 and 30 years of recovery, respectively. Subsequently, composite soil samples were taken at a depth of 20 cm and their nutrient content, pH, and texture were determined. It was observed that the soils were acidic (pH=4.73), with high percentages of sand, organic matter (6.62%), total nitrogen (N) (0.34%), available phosphorus (P) (28.21 ppm), potassium (K) (0.38 meq/100g) and aluminum (Al) (2.15 meq/100g), but with low amounts of calcium (Ca) (2 0.28 meq/100 g) and magnesium (Mg) (1.37 meq/100 g). The availability of P and K was high in both successional ages, while organic matter, total N, Ca, Mg, effective cation exchange capacity (ECEC), Al, and percentage of sand increased with succession, although pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. 38 meq/100g) and aluminum (Al) (2.15 meq/100 g), but with low amounts of calcium (Ca) (2.28 meq/100 g) and magnesium (Mg) (1.37 meq/100 g). The availability of P and K was high in both successional ages, while organic matter, total N, Ca, Mg, effective cation exchange capacity (ECEC), Al, and percentage of sand increased with succession, although pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. 38 meq/100g) and aluminum (Al) (2.15 meq/100 g), but with low amounts of calcium (Ca) (2.28 meq/100 g) and magnesium (Mg) (1.37 meq/100 g). The availability of P and K was high in both successional ages, while organic matter, total N, Ca, Mg, effective cation exchange capacity (ECEC), Al, and percentage of sand increased with succession, although pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. 37 meq/100 g). The availability of P and K was high in both successional ages, while organic matter, total N, Ca, Mg, effective cation exchange capacity (ECEC), Al, and percentage of sand increased with succession, although pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. 37 meq/100 g). The availability of P and K was high in both successional ages, while organic matter, total N, Ca, Mg, effective cation exchange capacity (ECEC), Al, and percentage of sand increased with succession, although pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. and the percentage of sand increased with the succession, although the pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation. and the percentage of sand increased with the succession, although the pH and clay decreased. In summary, an increase in the availability of sand and nutrients was evidenced, but also an increase in the acidity and toxicity of Al with the succession. Likewise, it was found that the recovery of the physicochemical conditions of the soil in mines is conditioned by the effect of organic matter and vegetation.