soil - Lublin

The rather small concentration of AMPA in the leaching solution testifies that
glyphosate is characterized by great stability in aerated conditions and indicates
small affinity to sorption (presence of 72.8% in water solution after 4 weeks after
amendment). Opposite to aerated conditions, where G+AMPA content was 74.8%
of introduced Glyphosate, only 26.6% of G+AMPA was found in the solution in
flooded treatments, of which 57% was detected as the MPA form.
On the contrary, the higher concentration of MFS in leaching solution indicates
fast transformation of fonofos in the aerated treatment. At low-oxygen incubation it
is decomposed rather slowly, which indicates the proportion between F and MFS
as 95% and 5% in leaching solution. In the anaerobic treatment with the 10-fold
dose of fonofos, about half (49.2%) of the pesticide introduced was found in the
leaching solution, while 40% of the metabolites was found in aerobic conditions.
At smaller doses of pesticide introduced, no presence of MFS was identified after 4
weeks of incubation. Figs 4 and 5 present the dehydrogenase and acid and alkaline
phosphomonoesterase activity changes as modified by aeration conditions and
dosage of pesticides.
Fig.4. Dehydrogenase activity in soil column after different doses of glyphosate (A)
and fonofos (B) amendments after 4 weeks of incubation
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