Field studies assessing the effect of dicyandiamide (DCD) on N transformations, pasture yields, N₂O emissions and N-leaching in the Manawatu region

Abstract

Nitrification inhibitors (NI) allow retention of soil nitrogen (N) in the ammonium (NH 4 + ) form for longer periods. Therefore, they can potentially increase pasture yields by decreasing N losses via nitrous oxide (N 2 O) emissions and nitrate (NO 3 − ) leaching. Multiple field experiments were conducted over 3 years at a Massey University dairy farm in the Manawatu region to determine the effect of the NI dicyandiamide (DCD) on soil N transformations, N 2 O emissions, pasture yields and NO 3 − leaching. Over the study period, DCD applied in autumn and winter had a half-life of 12-17 days and persisted in the soils between 42 and 84 days. Application of DCD inhibited the nitrification process, resulting in lower N 2 O emissions (54%-78% from urine patches). N 2 O emissions were further reduced using two applications of DCD, but more than two applications had no additional effect. Although the influence of DCD on pasture accumulation or NO 3 − leaching was not consistent, three applications of DCD increased pasture accumulation by 9% and reduced NO 3 − leaching by 22% in one of 2 years of the grazed drainage trial. However, the latter was largely influenced by lower drainage water volumes, rather than lower NO 3 − concentrations.

Effect of dicyandiamide (DCD) delivery method, application rate, and season on pasture urine patch nitrous oxide emissions

“…2; Table 2). Similar findings on the effectiveness of broadcasting DCD at 10 kg ha −1 for reducing N 2 O emissions have been reported in other studies (e.g., de Klein et al 2011;Luo et al 2013;Cameron et al 2014;de Klein et al 2014;Kim et al 2014;Ledgard et al 2014). Ledgard et al (2008) developed a novel-patented approach to strategic application of DCD to urine patches by directly administering the DCD to animals.…”

“…As discussed earlier, DCD is subject to degradation and leaching from the surface soil where urine has accumulated and N 2 O is being produced, leading to lower efficiency of DCD use (Luo et al 2008;Shepherd et al 2012;Kelliher et al 2014). Compared with the southern part of country, DCD would be less effective in the northern North Island of New Zealand, where the present study was conducted, due to warmer soil temperatures in winter de Klein et al 2014;Kim et al 2014;Ledgard et al 2014), as an increase in soil temperature has been shown to decrease the efficacy of DCD (Puttanna et al 1999). As well, the current study was conducted on a free-draining volcanic soil, which has naturally high rates of nitrification (Sarathchandra 1978) and rainfall/ drainage levels that are generally higher than those in many other dairying regions.…”

“…The efficacy of DCD is influenced by a number of factors, such as temperature, soil type, organic matter content, rainfall, and drainage (Amberger 1989). Studies in New Zealand have shown that broadcast application of DCD to grazed pasture can decrease N 2 O emissions by up to 70 % from urine patches (e.g., Di and Cameron 2005;de Klein et al 2011;Luo et al 2013;Welten et al 2013a;Cameron et al 2014;de Klein et al 2014;Kim et al 2014;Ledgard et al 2014). These studies also suggest that the effect of DCD on N 2 O emissions may also be affected by seasonality due to different amounts of rainfall and soil temperatures.…”

Evaluating the effects of dicyandiamide (DCD) on nitrogen cycling and dry matter production in a 3-year trial on a dairy pasture in South Otago, New Zealand

“…The results of trials in Waikato, Manawatu and Canterbury are presented in associated papers (Ledgard et al 2014;Kim et al 2014 andCameron et al 2014, respectively). This paper reports the results from the NOMR trial in South Otago.…”

Effect of nitrification inhibitors on the content of available nitrogen forms in the soil under maize (Zea mays, L.) growing

“…The concentration of ammonium nitrogen in the soil increased under nitrification inhibitor application. In another study, it was determined that, the application of dicyandiamide reduced NO3 -leaching by 22% (Kim et al, 2014). A series of studies reported by Di and Cameron over the past few years show a reduction of about 60 relative % in NO3 -leaching (Di and Cameron, 2005;Di and Cameron, 2006;Di et al, 2007;Singh and Verma, 2007).…”