High P losses in the soil–plant system (Table 3) were observed
under chisel + fallow (36 and 37 kg ha1), which can be explained
by the absence of cover crops in the spring, increasing the soil’s
susceptibility to the P fixation process. Additionally, even though
chiseling is a low-till practice, it may have contributed to increased
contact between phosphate ions and soil colloids and, consequently,
P fixation (Novais et al., 2007). The triticale/millet
treatment also led to a large decrease in P in the soil–plant system
during the experiment, but these results may be related to the high
amount of millet roots found in this treatment (Calonego and
Rosolem, 2010), resulting in greater P storage in radical tissues,
which was not considered when calculating the P budget in the
system (Eq. (2)).