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Modelling DCD effect on nitrate leaching under controlled conditions

Iris Vogeler A C , Adeline Blard B and Nanthi Bolan B

A HortResearch, Palmerston North, New Zealand.

B Institute of Natural Resources, Massey University, New Zealand.

C Corresponding author. Email:

Australian Journal of Soil Research 45(4) 310-317
Submitted: 22 December 2006  Accepted: 23 May 2007   Published: 28 June 2007


Effects of nitrogen losses through nitrate leaching are one of the major environmental issues worldwide. To determine the potential effect of dicyandiamide (DCD), a nitrification inhibitor, on the transformation of urea nitrogen and subsequent nitrate leaching, incubation and column leaching experiments were performed. Tokomaru silt loam soil was treated with urea, DCD, or urea plus DCD. A control was also used.

In the laboratory incubation experiment, the conversion of urea to ammonium (i.e. ammonification process or urea hydrolysis) occurred within a day, thereby increasing the soil pH from 5.8 to 6.9. DCD did not affect the ammonification process. However, DCD did slow down the subsequent oxidation of ammonium to nitrate (i.e. nitrification process). The half-life time of ammonium in this soil was increased from 9 days for the urea treatment to 31 days for the urea + DCD treatment. The production of nitrate was 5 times slower when DCD was added.

In the leaching experiments, half the columns were leached after 1 day of incubation (Day 1), the other half 7 days later (Day 7). For Day 1, no significant differences in nitrate leaching could be seen between the treatments, as the nitrification had not yet taken place. For Day 7, DCD decreased nitrate leaching by 71% with a corresponding decrease in nitrate-induced cation leaching, including ammonium. Thus, DCD seems to be effective in decreasing both ammonium and nitrate leaching, but its high solubility and thus mobility could be a limitation to its use.

The convection–dispersion equation, including source–sink terms for nitrogen transformations, ammonification, and nitrification rate constants, and a factor for nitrification inhibition by DCD, accounting for degradation and efficiency of DCD, could be used reasonably well to simulate nitrate leaching from the column leaching experiments. However, model parameter values for nitrification rate, and efficiency and decay rate for DCD, were different from those obtained from the incubation experiments, which was probably because of the difference in water content of soil between the incubation and leaching experiments.

Additional keywords: CDE (convection disperion equation), DCD decay rate, incubation, leaching experiment, ammonium.


Blackmore LC , Searle PL , Daly BK (1987) Methods for chemical analysis of soils. NZ Soil Bureau Scientific Report No. 80.

Bolan NS Saggar S Singh J 2004 The role of inhibitors in mitigating nitrogen losses in grazed pasture. New Zealand Soil News 42

Cookson WR Cornforth IS 2002 Dicyandiamide slows nitrification in diary cattle urine patches: effects on the soil solution composition, soil pH and pasture yield. Soil Biology & Biochemistry 34 1461 1465

Cowie JD (1978) Soils and Agriculture of Kairanga Country, North Island, New Zealand. New Zealand Soil Bureau Bulletin 33 DSIR.

Di HJ Cameron KC 2002 a Nitrate leaching in temperate agroecosystems: sources, factors and mitigating strategies. Nutrient Cycling in Agroecosystems 64 237 256 doi:10.1023/A:1021471531188

Di HJ Cameron KC 2002 b The use of a nitrification inhibitor, dicyandiamide (DCD), to decrease nitrate leaching and nitrous oxide emissions in a simulated grazed and irrigated grassland. Soil Use and Management 18 395 403 doi:10.1079/SUM2002151

Di HJ Cameron KC 2004 Effects of the nitrification inhibitor dicyandiamide on potassium, magnesium and calcium leaching in grazed grassland. Soil Use and Management 20 2 7 doi:10.1079/SUM2003205

van Genuchten MTH , Wierenga PJ (1986) Solute dispersion coefficients and retardation factors. In ‘Methods of soil analysis. Part I. Physical and mineralogical methods’. Agronomy No. 9, 2nd edn (Ed. A Klute) pp. 1025–1054. (ASA: Madison, WI)

Grundmann GL Renault P Rosso L Bardin L 1995 Differential effects of soil water content and temperature on nitrification and aeration. Soil Science Society of America Journal 59 1342 1349

Hallinger PR Wallnöfer PR Goldbach H Amberger A 1990 Several aspects of bacterial dicyandiamide degradation. Die Naturwissenschaften 77 332 334

Irigoyen I Muro J Azpilikueta M Aparicio-Tejo A Lamsfus C 2003 Ammonium oxidation kinetics in the presence of nitrification inhibitors DCD and DMPP at various temperatures. Australian Journal of Soil Research 41 1177 1183 doi:10.1071/SR02144

Iskandar IK Selim HM 1981 Modelling nitrogen transport and transformations in soils: 2. Validation. Soil Science 131 303 312 doi:10.1097/00010694-198105000-00007

Jury WA , Gardner WR , Gardner WH (1991) ‘Soil physics.’ 5th edn (John Wiley and Sons, Inc.: New York)

Keeney DR (1980) Factors affecting the persistence and bioactivity of nitrification inhibitors. In ‘Nitrification inhibitors-potentials and limitations’. (Eds M Stelly, JJ Meisinger, GW Randall, ML Vitosh, DM Kral) pp. 33–46. (American Society of Agronomy, Soil Science Society of America: Madison, WI)

Kumar V Wagenet RJ 1984 Urease activity and kinetics of urea transformation in soils. Soil Science 137 263 269

Kutzova RS Tribis Zh M Mikhaleva LV Smirnova VF 1993 Influence of nitrification inhibitors on microbiological processes of the nitrogen cycle in the soil. Eurasian Soil Science 25 68 84

McCarty GW Bremner JM 1989 Laboratory evaluation of dicyandiamide as a soil nitrification inhibitor. Communications in Soil Science and Plant Analysis 20 2049 2065

Puttanna K Nanje Gowda NM Prakasa Rao EVS 1999 Effect of concentration, temperature, moisture, liming and organic matter on the efficacy of the nitrification inhibitors benzotriazole, o-nitrophenol, m-nitroaniline and dicyandiamide. Nutrient Cylcing in Agroecosystems 54 251 257

Rajbanshi SS Benckiser G Ottow JCG 1992 Effects of concentration, incubation temperature, and repeated applications on degradation kinetics of dicyandiamide (DCD) in model experiments with a silt loam soil. Biology and Fertility of Soils 13 61 64 doi:10.1007/BF00337336

Rodgers GA Penny A Hewit MV 1985 Effect of nitrification inhibitors on uptake of mineralised nitrogen and on yield of winter cereals grown on sandy soil after ploughing old grassland. Journal of the Science of Food and Agriculture 36 915 924 doi:10.1002/jsfa.2740361003

Slangen JHG Kerkhoff P 1984 Nitrification inhibitors in agriculture and horticulture: a literature review. Fertilizer Research 5 1 76 doi:10.1007/BF01049492

Thomas SM Ledgard SF Francis GS 2005 Improving estimates of nitrate leaching for quantifying New Zealand’s indirect nitrous oxide emissions. Nutrient Cycling in Agroecosystems 73 213 226 doi:10.1007/s10705-005-2476-8

Tillman RW Scotter DR 1991 Movement of solutes associated with intermittent soil water flow. II. Nitrogen and cations. Australian Journal of Soil Research 29 185 196 doi:10.1071/SR9910185

Vilsmeier K 1979 Kolorimetrische Bestimmung von Dicyandiamide Böden Zeitschrift für. Pflanzernaehrung und Bodenkunde 142 792 798 doi:10.1002/jpln.19791420605

Wagenet RJ Biggar JW Nielsen DR 1977 Tracing the transformations of urea fertiliser during leaching. Soil Science Society of America Journal 41 896 902

Williamson JC Menneer JC Tortrens RS 1996 Impact of dicyandiamide on the internal nitrogen cycle of a volcanic, silt loam soil receiving effluent. Applied Soil Ecology 4 39 48

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