Modeling nutrient losses in an Oxisol under different management systems and rainfall events

ABSTRACT

This study aimed to model nutrient losses in an Oxisol under varied soil properties and vegetation cover. The experimental area was located at the Paraná Rural Development Institute, in Santa Tereza do Oeste, Paraná, Brazil. The treatments consisted of six cover crops in summer, six cover crops in winter, and management systems no-tillage (NT) traditional (control), NT with gypsum, and NT with scarification. Nutrient data were collected at each natural rainfall through sample collection from collection troughs. The design was completely randomized, and the data were adjusted using an exponential function of two variables, as a function of soil density, macroporosity, straw dry mass, green cover, and rainfall. Greater losses of Mg and Ca was related to higher soil density and lower macroporosity. Lower losses of Mg, Ca, K, and P were associated with lower straw dry mass and higher green cover. K and P losses were stable for all soil density values, but they decreased with an increase in macroporosity.

Key words water erosion; models; optimization