Quantification of soil nitrites in an oil palm field in the Colombian eastern plains and their relation with rainfall, spatial variability and chisel plowing
Author
Carreño, Jorge
Acosta G., Álvaro
Munévar M., Fernando
Cuéllar S., Mónica C.
Como citar
Publicación:
Revista Palmas; Vol. 20 Núm. 4 (1999); 11-17
0121-2923
Revista Palmas; Vol. 20 Núm. 4 (1999); 11-17
0121-2923
Abstract
Preliminary research carried out by Cenipalma has shown that the soils planted with oil palm [Elaeis guineensis Jacq.) in the east of Colombia frequently have unfavorable physical conditions such as surface clay horizons, high compaction, slow hydraulic conductivity and prolonged periods of water saturation. Those conditions limit soil aeration to a point that reduction may occur. The inorganic forms of nitrogen are among the soil constituents whose dynamics may be altered by reduction, mainly because under anaerobic conditions nitrites may accumulate. A survey was done in order to determine the spatial and temporal variability of soil nitrites in the Upía region. The study was conducted at Palmas de Casanare estate (Casanare, Colombia) where the soils (Tropaquepts) have limitations for drainage. In each of four soils a sampling plot was established, consisting of a central palm tree and the nearest four palms, which were equidistant to the central one. The imaginary lines linking the central palm to each of the surrounding ones were called transects; thus two transects cross the harvest path and the other two cross the frond heap path. On each transect, the soil was sampled at four different distances from the base of the palm, and at each of these points at three different depths. The nitrite concentration in the soil was measured in the rainy season as well as in the dry season, and then two times after the soil had been chisel plowed. Since four replications were made of each sample, the study included a total of 1,536 samples. Statistically significant differences (?=5%] were found in nitrite concentration among seasons, transects and depths. No significant differences were found among soils. Nitrite concentration was higher in the wet than in the dry season. Higher nitrite concentrations were found in the harvest paths than in the frond-heap paths. During the rainy season, the nitrite concentration in soil under the harvest paths was higher than the level reported in the literature to be toxic to plants. Chisel plowing lowered the nitrite concentration in the soil and changed its pattern of spatial variability. The variability in time and space found in this study should be kept in mind for future research on this subject. Investigaciones realizadas por Cenipalma han mostrado que, con frecuencia, los suelos de las plantaciones de palma de aceite (Elaeis guineensis Jacq.) presentan condiciones físicas adversas, tales como capas superficiales de arcilla, alta compactación, conductividad hidráulica lenta o períodos prolongados de alta humedad, las cuales limitan la aireación del suelo, pudiéndose presentar condiciones de reducción. Entre los principales grupos de constituyentes del suelo cuya dinámica se ve alterada por este estado de reducción, están las formas inorgánicas de nitrógeno, debido a que la condición de anaerobios es uno de los factores que propicia la acumulación de nitritos. Para conocer la variabilidad espacial y temporal de la concentración de nitritos se realizó un muestreo sistemático en suelos con limitaciones para el drenaje (Tropaquepts), de la plantación Palmas del Casanare en la región del Upía, departamento del Casanare, Colombia. En cada uno de cuatro suelos se estableció una unidad experimental de muestreo conformada por una palma central y las cuatro palmas más próximas y equidistantes a la primera. Las líneas imaginarias que unen la palma central con cada una de las circundantes se denominaron trayectos; de esta forma, dos trayectos cruzaban la calle de cosecha y dos las calles de acumulación de hojas de poda (palera). En el suelo se tomaron muestras a cuatro distancias a partir de la base de la palma, y en cada distancia, a su vez, a tres profundidades dentro de cada trayecto. La concentración de nitritos se evaluó tanto en época de lluvia como en época seca, y luego en dos oportunidades más después de haber aireado el suelo mediante el uso de un arado de cincel. Como de cada punto de muestreo se tomaron cuatro muestras (réplicas), el estudio comprendió un total de 1.536 muestras. Se encontraron diferencias significativas (?=5%) en la concentración de nitritos entre épocas, calles y profundidades. No se encontraron diferencias significativas entre suelos. La concentración de nitritos fue mayor en la época de lluvia que en la época seca, y mayor en las calles de cosecha que en las paleras. La concentración de nitritos en la época húmeda en las calles de cosecha superó los niveles considerados en la literatura como fitotóxicos. La labor de cincelado permitió disminuir las concentraciones de nitritos en el suelo y cambiar su patrón de variabilidad espacial. La variabilidad temporal y espacial que se encontró, debe tenerse en cuenta en estudios futuros relacionados con el tema
Preliminary research carried out by Cenipalma has shown that the soils planted with oil palm [Elaeis guineensis Jacq.) in the east of Colombia frequently have unfavorable physical conditions such as surface clay horizons, high compaction, slow hydraulic conductivity and prolonged periods of water saturation. Those conditions limit soil aeration to a point that reduction may occur. The inorganic forms of nitrogen are among the soil constituents whose dynamics may be altered by reduction, mainly because under anaerobic conditions nitrites may accumulate. A survey was done in order to determine the spatial and temporal variability of soil nitrites in the Upía region. The study was conducted at Palmas de Casanare estate (Casanare, Colombia) where the soils (Tropaquepts) have limitations for drainage. In each of four soils a sampling plot was established, consisting of a central palm tree and the nearest four palms, which were equidistant to the central one. The imaginary lines linking the central palm to each of the surrounding ones were called transects; thus two transects cross the harvest path and the other two cross the frond heap path. On each transect, the soil was sampled at four different distances from the base of the palm, and at each of these points at three different depths. The nitrite concentration in the soil was measured in the rainy season as well as in the dry season, and then two times after the soil had been chisel plowed. Since four replications were made of each sample, the study included a total of 1,536 samples. Statistically significant differences (?=5%] were found in nitrite concentration among seasons, transects and depths. No significant differences were found among soils. Nitrite concentration was higher in the wet than in the dry season. Higher nitrite concentrations were found in the harvest paths than in the frond-heap paths. During the rainy season, the nitrite concentration in soil under the harvest paths was higher than the level reported in the literature to be toxic to plants. Chisel plowing lowered the nitrite concentration in the soil and changed its pattern of spatial variability. The variability in time and space found in this study should be kept in mind for future research on this subject.
Palabras clave:
palma de aceite
elaeis guineensis
suelo
factores edáficos
nitritos
precipitación
propiedades fisicoquímicas del suelo
compactación del suelo
palma de aceite
elaeis guineensis
suelo
factores edáficos
nitritos
precipitación
propiedades fisicoquímicas del suelo
compactación del suelo