Soil pH does not interfere with nitrification inhibitor efficiency for reducing N2O emissions from soils treated with concentrated vinasse and urea

This study addresses the assessment of potential nitrification inhibitor (NI) 3,4-dimethylpyrazol-phosphate for mitigation of nitrous oxide (N2O) emissions from the joint application of concentrated vinasse (CV) and urea in soils under different pHs. An incubation experiment was performed under controlled conditions to evaluate the effect of the organo-mineral fertilization containing CV and Urea (N rate: 120 kg N ha(-1)) on N2O emissions, as well as the efficiency of the NI addition, at different soil pHs (4.5 and 6.0). The treatments were: Control; Urea; Urea + NI; CV; CV + Urea; and CV + Urea + NI. The soil pH greatly influenced the N2O production with emissions 3.8-fold higher at pH 6.0 than at pH 4.5. Besides, the joint application of CV + Urea increased the N2O emissions by 1.3 and 2.9-fold (185 and 1141 mg N m(-2)) compared to Urea treatment (138 and 391 mg N m(-2)) at pH 4.5 and 6.0, respectively. The addition of NI was efficient under both soil pHs, decreasing N2O emissions by 92 and 88 % in the Urea treatment and 71 % and 91 % in the CV + Urea treatment at pH 4.5 and 6.0, respectively. Our results indicate that soil pH has a large influence on N2O emissions and little effect on the NI efficiency.

Automated summary

This study assessed the effectiveness of a potential nitrification inhibitor in reducing nitrous oxide emissions from the joint application of concentrated vinasse and urea in soils with different pH values. The results showed that soil pH had a significant impact on N2O emissions, but had little effect on the efficiency of the nitrification inhibitor.