Influence of four nematicides on soil nitrogen mineralisation and nitrogen uptake hy white clover in a yellow-grey earth

摘要

The influence of commercial formulations of four nematicides, applied at recommended rates, on nitrogen mineralisation and nitrification in a faIl ow soil (Kokatau silt loam) was investigated. Nitrogen mineralisation was very active at 0#x2013;5 and 5#x2013;15 cm depths and total levels of mineral N at 0#x2013;15 cm depth could exceed 200 kg/ha. Treatment with methyl bromide initially inhibited nitrification and resulted in high levels of ammonium N; 5ubsequent conversion to nitrate N was slow in the field but more rapid under moister soil conditions in the laboratory. #x2018;DD#x2019; had a similar, but less marked, effect. #x2018;Nemagon#x2019;, at two concentrations, and #x2018;Mocap#x2019; had little effect.