Authors:
Ferisman. Tindaon*
, Ferlando Jubelito Simanungkalit
, Dunan Naibaho
, Yanto Raya Tampubolon
, Ferlist
Rio Siahaan
, Shanti Desima Simbolon1 and Parlindungan Lumbanraja, Indonesia. |
Abstract:
Ecotoxicological risks of non-target soil microbial processes, caused by three nitrification
inhibitors (Nis) 3,4dimethylpyrazolephosphate=DMPP, 4-Chlor-methylpyrazole= ClMP and
dicyandiamide-DCD) were estimated in three different types of soils by employing the
dehydrogenase activity (DHA). DHA was spectrophotometrically quantified. NIS concentration
dependent and for evaluating inhibition effects no observable effect level=NOEL, as well as
effective dose ED10 and ED 50(10% and 50% inhibition) were calculated and presented in dose
response curves. The inhibition is most distinct in sandy soils. At an about 30–70 times higher NI
application rate than the recommended field application rate must accumulate in soils before the
NOEL for microbial non target processes is surpassing and harmed microbial cells become
observable. ClMP exhibited the strongest influence on non-target microbial soil processes. It is
suggested that the data presented here could be very useful in helping to set permissible limit for
agrochemicals soil pollution. An Ecological Dose Range to describe the increased rate of
inhibition upon increasing concentrations of a pollutant was proposed. Remarks were made
about the way this model must be used together with applications in other fields of soil biological
research. |
