Soil management in Brazilian states: comparative analyzes of Physical and Monetary Soil Nutrient Balance in 2005 and 2015

Resumo

Intensive agricultural production tends to stimulate the outflow of nutrients from the soil, requiring producers to properly manage the soil to avoid reducing fertility in the following crops. Thus, the objective was to estimate the annual monetary balance of nutrients in the soil of six Brazilian states that present the highest consumption of inorganic fertilizers in the years 2005 and 2015. The Annual Balance of Nutrients in Soil was used to calculate the physical and monetary balance of nutrients, in the main crops of these States, by quantifying the export of N, P, K from the soil by plants and the insertion of nutrients, through the application of fertilizers, fertigation, and biological fixation. The monetary balance of N, P and K added for the six states was positive and increased by 114% between 2005 and 2015, however, the balance of P for the state of Paraná was negative in 2015 reaching R$ 1,769.17. The balances and Mato Grosso, Rio Grande do Sul, and Paraná were higher concerning Goiás, São Paulo, and Minas Gerais. Except for Paraná, related to P, there was no positive depreciation of the associated NPK nutrients. The different flows, in the comparison among states, are caused by the different dynamics of land use, mainly in the size of the corn and soybean cultivation area.