Effective mitigation of nitrate leaching and nitrous oxide emissions in intensive vegetable production systems using a nitrification inhibitor, dicyandiamide

Abstract

Purpose Vegetable production is one of the most intensive agricultural systems with high rates of nitrogen (N) fertilizer use and irrigation, conditions conducive for nitrate (NO 3 − ) leaching, and nitrous oxide (N 2 O) emissions. The objective of this study was to determine the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in decreasing NO 3 − leaching and N 2 O emissions in vegetable production systems. Materials and methods Twenty-four undisturbed soil monolith lysimeters (610 mm in diameter; 700 mm in depth; surface area, 0.29 m 2 ) with two different soils, Huangzongrang (alfisol) and Chaotu (fluvisols), were collected and installed in a field lysimeter facility in Central China under irrigated vegetable production conditions. Urea fertilizer was applied at 650 kg Nha −1 , and DCD was applied at 10 kg ha −1 to the lysimeters planted with three kinds of vegetables (capsicum, Capsicum annuum L.; amaranth, Amaranthus mangostanus L.; radish, Raphanus sativus L.). Results and discussionThe results showed that DCD reduced NO 3 − leaching by 58.5% and 36.2% and N 2 O emissions factor by 83.8% and 72.7% in the two soils. The average NO 3 − -N concentration in the drainage water was decreased from 4.9 mg NL −1 to 2.3 mg NL −1 and from 4.4 mg NL −1 to 3.3 mg NL −1 , in the Huangzongrang and Chaotu soils, respectively. In addition to the environmental benefits, the use of DCD also increased the yields of capsicum and radish in alfisol soil significantly (P<0.01); only the amaranth yield in fluvisol soil was declined (P<0.01), and the other vegetables yields were not affected. Total N concentrations of the three vegetables were increased significantly (P<0.01) with the application of DCD with urea compared with urea alone. These results showed that the nitrification inhibitor DCD has the potential to significantly reduce NO 3 − leaching and N 2 O emissions and to make vegetable farming more environmentally friendly.Conclusions These results demonstrated that the use of the nitrification inhibitor DCD can significantly reduce NO 3 − leaching, N 2 O emissions, and the average NO 3 − -N concentration in the drainage water, while increasing the fertilizer N efficiency in the vegetable production system.

Effects of dicyandiamide (DCD) on nitrate leaching, gaseous emissions of ammonia and nitrous oxide in a greenhouse vegetable production system in northern China

“…Generally, the increase of NH 3 -N concentrations in this study were significantly lower in the recommended N treatments with the addition of DCD and optimum managed irrigation, and there was an average reduction of 49.34-55.54% compared with urea alone (TN þ TMI). This result is similar to those of Cui et al (2011) in an intensive vegetable production lysimeter study, where reductions of 36.2-58.5% were reported. These results suggest that DCD delayed the oxidation NH þ 4 to NO À 3 -N following the hydrolysis of urea (Vogeler et al 2007;Ding et al 2011).…”

“…This result is consistent with those reported by Wu et al (2011). The highest total N 2 O emission of 7.65 kg N ha À1 was observed in treatment B, urea with traditional managed irrigation (TN þ TMI), which is in the typical range of 1.1-17.2 kg N ha À1 from intensive vegetable production systems reported by other researchers (Lu et al 2008;He et al 2009;Zhang et al 2010;Cui et al 2011;Wu et al 2011). However, the presence of DCD combined with optimum N and irrigation significantly reduced N 2 O emission by 84.07-96.19% over urea alone, which was greater than the reductions reported by Di and Cameron (2006), and Di et al (2007) in grazed pasture systems.…”

“…DCD (containing 66.7% N) is the most widely used nitrification inhibitor because it is cheaper, nontoxic, less volatile, relatively water soluble, and relatively benign to non-target microbial communities (Zacherl and Amberger 1990;O'Callaghan et al 2010;Di et al 2011). Many studies have shown that DCD can significantly decrease NO À 3 leaching and N 2 O emissions from cropping systems or grazed pasture systems Cameron 2002b, 2003;Di et al 2007;Jumadi et al 2008;Cui et al 2011). However, the persistence of excess NH þ 4 -N in soil for a longer time in alkaline soils may increase NH 3 volatilization (Gioacchini et al 2002;Banerjee et al 2002;Asing et al 2008) and some studies have reported that the amount of NH 3 volatilisation increased after the application of DCD (Banerjee et al 2002;Mkhabela et al 2006;Pi et al 2009), while others showed DCD reducing NH 3 volatilisation (Dendooven et al 1998;Tao et al 2008).…”

Effects of nitrification inhibitors (DCD and DMPP) on nitrous oxide emission, crop yield and nitrogen uptake in a wheat–maize cropping system

“…The application of DCD and DMPP together with NH + 4 -based fertilizers, cow urine or cattle slurry has demonstrated efficiency in reducing the N losses in forms of nitrous oxide (N 2 O) emission and NO − 3 leaching while increasing the yield and use efficiency of fertilizer N in croplands and grasslands (Weiske et al, 2001;Majumdar et al, 2002;Zaman et al, 2009;Cui et al, 2011;Di and Cameron, 2012;Moir et al, 2012;Pfab et al, 2012). Compared with DCD, a comparable or even better inhibition effect on N 2 O emission and NO − 3 leaching can be achieved with approximately 1/25 to 1/2 of the application rate for DMPP (Weiske et al, 2001;Belastegui-Macadam et al, 2003;Di and Cameron, 2012).…”

“…There are a variety of new management practices and technologies that can promote N use efficiency and alleviate environmental pollution. One of the mitigation technologies that has proved to be highly effective in reducing fertilizer N losses and increasing N use efficiency and yield in a few cropping systems is the application of nitrification inhibitors (Majumdar et al, 2002;Zaman et al, 2009;Cui et al, 2011;Moir et al, 2012).…”