Environmental benefits of reducing N rates for coffee in the Cerrado

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An intensification of agriculture in the Brazilian Cerrado during the last four decades has resulted in unintended consequences such as increased groundwater and surface water pollution due to excessive N fertilization. To address these problems within a coffee (Coffea arabica L.) orchard, the process-based ANIMO model was used to simulate nitrate-nitrogen (NO3-N) leaching and plant nitrogen (N) uptake for several rates of N (200–800kgh−1y−1). Effects of splitting N applications from three times per year to every other day were also evaluated for a Typic Hapludox within the Cerrado. Statistical analysis of ANIMO outputs showed that simulated soil solution NO3-N concentrations were in agreement with experimental measurements collected for an entire year. Simulated annual N uptake was also in agreement with average measured N uptake by the coffee plants. An evaluation of the simulation scenarios showed that: i) the most efficient N recovery was associated with N rates between 200 and 400kgNha−1y−1 that were split into at least seven applications per year; ii) N recovery at rates between 200 and 300kgNha−1 y−1 were efficient with or without split application; and iii) the most environmentally friendly N management strategy was the application of between 200 and 300kgNha−1y−1 using at least seven splits. Reducing the N rate from 600 to 400kgNha−1y−1 increased plant N recovery efficiency by 8–12% and reduced NO3-N leaching by 28 to 47%. Predicted NO3-N leaching and N plant uptake results confirm that better N management strategies can be developed for coffee plantations and other crops grown in the Cerrado.