The extent of degradation increased with increasing water holding capacity; fipronil degradation was greatest at 60% MWHC, followed by the soils with 30% MWHC and 15% MWHC.
Laboratory experiments also showed the detection of high concentrations of the sulfide derivative in the nonsterile soils with moisture contents above 50% (up to 165% MWHC) compared with low MWHC soils (15%).
The concentrations of the sulfone derivative in nonsterile soils with MWHC of 50-165% were all below 0.
During the field trial, soil moisture contents varied from 8% to 52% MWHC; however, MWHC was below 30% MWHC for majority of the time.
7 kBq/g soil), and the moisture contents to 20%, 50%, or 100% MWHC.
The rates of mineralisation of atrazine in Te Awa, Twyford, and Twyford 2 soils were measured over 263 days at 22 [degrees] C and at 100% MWHC.
Increasing the moisture content from 20% to 50% or 100% MWHC also increased the rate of mineralisation; the increases were greater in surface soil than in subsoil.