Effects of acetochlor on transformation of urea nitrogen in soil at different nitrogen fertilizer application rates

In order to assess the effects of acetochlor on transformation of urea nitrogen in soil at different nitrogen fertilizer application rates. An incubation experiment was conducted under laboratory conditions with 7 treatments including nitrogen (0, 75, 150 and 300 mg/kg), nitrogen (75, 150 and 300 mg/kg) plus acetochlor (10 mg/kg, active ingredient). The results showed that, acetochlor had no significantly effect on soil urea hydrolysis and nitrification at 75 mg/kg nitrogen concentration treatments. However, significant negative effect on soil urea hydrolysis was observed at 150 and 300 mg/kg nitrogen concentration treatments (P P < 0.01). This study demonstrated that acetochlor markedly affected the nitrogen transformation in soil. However, under different nitrogen fertilizer application rates, different impacts on the processes of nitrogen transformation were detected.