The chisel + fallow treatments altered soil K dynamics, resulting
in a small decrease in available K in the 0.10–0.20 m layer (Table 5).
These results could be explained by the absence of cover crops,
which could recycle K from deeper soil layers in this region.
Furthermore, chiseling resulted in K leaching to deeper layers
(Table 5), with an increased available K content being detected in
the 0.20–0.40 m layer when sunflowers were grown in the
autumn–winter season. A high K movement to the 0.40–0.60 m
layer was observed when triticale was grown, although other
treatments were also have resulted in some K accumulation in this
layer when compared with the initial soil analysis. The absence of
plants for a certain period may have contributed to K leaching to
greater depths; according to Rosolem et al. (2006a), soil covering
can prevent nutrient leaching to deeper layers, in addition to
increasing the K content near the soil surface.