Abstract
In this study the effects of adopting circular agricultural practices on the efficiency and recovery of potassium (K) use under tropical conditions was evaluated. The assessment considered two commercial farms, i.e., 3 W Agronegócios (Farm 1) and Santa Helena (Farm 2), located in Brazil. The soil of both farms was under no-till and it was continuously covered throughout the year with cover and cash crops. There were two cropping seasons per year with maize intercropped with brachiaria grass (Urochloa ruziziensis). The leftovers from the silos and part of the crop residues were used to feed the confined animals or as organic compost for the production fields. 860 t (Farm 1) and 307 t (Farm 2) of K fertilizer was applied, while 524 t on Farm 1 and 226 t of K on Farm 2 was exported by the crops and in the live weight of the animals. Most of the K extracted by the crops was returned to the soil as residues. The adoption of circular agriculture practices such as the no-till, crop rotations, cover and cash crops, maize intercropped with grass, and integrated with livestock, resulted in a high K recovery for both farms, i.e. 85% for Farm 1 and > 90% for Farm 2. Further research is needed to evaluate these practices and obtain measurements that were not available in the current on-farm study.