Artículo de revista
Preferential flow paths in two alluvial soils with long-term additions of pig slurry in the Mediterranean zone of Chile
Fecha
2015Registro en:
Soil Research Volumen: 53 Número: 4 Páginas: 433-447 (2015)
DOI: 10.1071/SR14264
Autor
Fuentes, Ignacio
Casanova Pinto, Manuel
Seguel Seguel, Oscar
Padarian Campusano, José Sergei
Nájera de Ferrari, Francisco
Salazar Guerrero, Osvaldo
Institución
Resumen
Spatial variability of soil hydraulic properties helps to understand the complexity and dynamic
patterns of solute distributions in soils. This study assessed the effects of slurry additions and
soil physical properties on preferential flow and nitrate concentrations in two Mediterranean
soils of central Chile under conventional agriculture management with long-term slurry
additions. Two alluvial basins continuously cropped with maize (Zea mays) were selected,
Pichidegua (Mollic Xerofluvent) and San Pedro (Fluventic Humixerept). Soils that had been
amended with pig slurry were compared with unamended controls. Soil texture, bulk density,
particle density, organic matter, porosity and hydraulic conductivity (Ks) were measured. Soil
nitrate concentrations at different depths were determined every 2 weeks during the study, and
a dye tracer test using Brilliant Blue FCF was conducted on each soil. Digital picture analysis
was then performed to classify flow types in the soil profiles through the distribution of stained
path width. Stained path width allowed classification of soil flow types. Preferential flow showed
no evidence of being affected by pig slurry; the stained patterns were mainly explained by tillage
and soil physical properties, such as texture and Ks. Matrix flow-types in the first horizon
grading to macropore flow-types at depth characterised all profiles, except San Pedro amended
soil, where homogeneous matrix flow dominated through the entire profile. Concentrations of
nitrate showed temporal variation during the measurement season, mainly due to the
mineralisation-immobilisation budget and leaching, both triggered by Mediterranean climate
conditions. Physical properties helped to explain nitrate distribution in the studied soils.