The nitrification inhibitor DMPP applied to subtropical rice has an inconsistent effect on nitrous oxide emissions

Although there is growing evidence that the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) can lower soil nitrous oxide (N2O) emissions in temperate environments, there is little evidence of its efficacy in subtropical or tropical environments where temperatures and rainfall intensities are typically higher. We investigated N2O emissions in field-grown aerobic rice in adjacent fields in the 2013–14 and 2014–15 seasons in a subtropical environment. Crops were topdressed with 80 kg nitrogen (N) ha–1 before rainfall, as either urea, urea + DMPP (at 1.6 kg DMPP t–1 urea: ‘urea-DMPP’) or a blend of 50% urea and 50% urea-DMPP in the 2013–14 season, and urea, urea-DMPP or polymer (3 month)-coated urea (PCU) in the 2014–15 season. DMPP-urea significantly (P < 0.05) lowered soil N2O emissions in the 2013–14 season during the peak flux period after N fertiliser application, but had no effect in 2014–15. The mean cumulative N2O emissions over the entire growing period were 190 g N2O-N ha–1 in 2013–14 and 413 g N2O-N ha–1 in 2014–15, with no significant effect of DMPP or PCU. Our results demonstrate that DMPP can lower N2O emissions in subtropical, aerobic rice during peak flux events following N fertiliser application in some seasons, but inherent variability in climate and soil N2O emissions limited the ability to detect significant differences in cumulative N2O flux over the seasonal assessment. A greater understanding of how environmental and soil factors impact the efficacy of DMPP in the subtropics is needed to formulate appropriate guidelines for its use commercially.

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Effect of dicyandiamide (DCD) on nitrous oxide emissions from cow urine deposited on a pasture soil, as influenced by DCD application method and rate

Animal Production Science ◽

10.1071/an15500 ◽

2016 ◽

Vol 56 (3) ◽

pp. 350 ◽

Cited By ~ 4

Author(s):

J. Luo ◽

S. Ledgard ◽

B. Wise ◽

S. Lindsey

Keyword(s):

Nitrous Oxide ◽

Animal Feed ◽

Nitrification Inhibitor ◽

Application Rate ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Late Autumn ◽

Cow Urine ◽

Urine Patch ◽

Reduction Effect

Animal urine deposited on pastoral soils during grazing is recognised as a dominant source of nitrous oxide (N2O) emissions. The nitrification inhibitor, dicyandiamide (DCD), is a potential mitigation technology to control N2O emissions from urine patches on grazed pastures. One delivery option is to include DCD in animal feed so that the DCD is targeted directly in the urine patch when excreted in the animal urine. The hypothesis tested in the present study was that DCD in urine, excreted by cows that were orally administered with DCD, would have the same effect as DCD added to urine after the urine is excreted. The study also aimed to determine the most effective DCD rate for reducing N2O emissions. Fresh dairy cow urine (700 kg N per ha) was applied to a free-draining silt loam pastoral soil in Waikato, New Zealand, in May (late autumn) or July (winter) of 2014, and was mixed with DCD at rates of 0, 10, 30 and 60 kg/ha. In late autumn, there was an equivalent treatment of urine (containing 60 kg DCD per ha) from DCD-treated cows. A static chamber technique was used to determine gaseous N2O emissions. An annual emission factor (EF3; the percentage of applied urine N lost as N2O-N) of 0.23% or 0.21% was found following late-autumn or winter applications of urine without DCD. Late-autumn application of urine containing DCD from oral administration to cows had the same significant reduction effect on N2O emissions as did DCD that was mixed with urine after excretion, at the equivalent DCD application rate of 60 kg/ha. Application of urine with DCD mixed with the urine after excretion at varying DCD rates showed a significant (P < 0.05) linear decrease in both N2O emissions and EF3 values.

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The effect of increasing rates of nitrogen fertiliser and a nitrification inhibitor on nitrous oxide emissions from urine patches on sheep grazed hill country pasture

Australian Journal of Experimental Agriculture ◽

10.1071/ea07238 ◽

2008 ◽

Vol 48 (2) ◽

pp. 147 ◽

Cited By ~ 30

Author(s):

Coby J. Hoogendoorn ◽

Cecile A. M. de Klein ◽

Alison J. Rutherford ◽

Selai Letica ◽

Brian P. Devantier

Keyword(s):

Nitrous Oxide ◽

New Zealand ◽

Nitrification Inhibitor ◽

N2o Emission ◽

Emission Factors ◽

Application Rate ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Hill Country ◽

Sheep Urine

Urine deposited by grazing animals represents the largest source of N2O emissions in New Zealand. Sheep-grazed hill pastures are an important component of New Zealand pastoral land, but information on N2O emissions from these areas is limited. The purpose of this study was to investigate the effect of increasing rates of fertiliser nitrogen and of a nitrification inhibitor on N2O emissions from urine patches. The study was carried out in grazed paddock-scale trials at the Ballantrae and Invermay Research Stations, New Zealand. The fertiliser N treatments were 0, 100, 300 and 750 (500 for Invermay) kg N/ha.year. Nitrous oxide measurements were conducted in the spring of 2005 and 2006, following applications of synthetic sheep urine with or without dicyandiamide (DCD) in these four N treatments. In both years and at both sites, N2O emissions increased with N fertiliser application rate in both urine and non-urine affected areas. The addition of DCD to the synthetic urine reduced N2O emissions from the urine affected areas during the measurement period by 60–80% at Ballantrae and by 40% at Invermay. The N2O emission factors for the artificial sheep urine (expressed as N2O-N lost as % of N applied) ranged from 0.01 to 1.06%, with the higher values generally found in the high N fertiliser treatments. The N2O emission factors were generally less than or similar to those from sheep urine applied to flat land pasture.

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Effect of enhanced efficiency fertilisers on nitrous oxide emissions in a sub-tropical cereal cropping system

Soil Research ◽

10.1071/sr15332 ◽

2016 ◽

Vol 54 (5) ◽

pp. 544 ◽

Cited By ~ 22

Author(s):

Clemens Scheer ◽

David W. Rowlings ◽

Massimiliano De Antoni Migliorati ◽

David W. Lester ◽

Mike J. Bell ◽

...

Keyword(s):

Nitrous Oxide ◽

Crop Yields ◽

Cropping Systems ◽

Nitrification Inhibitor ◽

Cropping System ◽

Measuring System ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

N Fertilisers ◽

Polymer Coated Urea

To meet the global food demand in the coming decades, crop yields per unit area must increase. This can only be achieved by a further intensification of existing cropping systems and will require even higher inputs of N fertilisers, which may result in increased losses of nitrous oxide (N2O) from cropped soils. Enhanced efficiency fertilisers (EEFs) have been promoted as a potential strategy to mitigate N2O emissions and improve nitrogen use efficiency (NUE) in cereal cropping systems. However, only limited data are currently available on the use of different EEF products in sub-tropical cereal systems. A field experiment was conducted to investigate the effect of three different EEFs on N2O emissions, NUE and yield in a sub-tropical summer cereal cropping system in Australia. Over an entire year soil N2O fluxes were monitored continuously (3h sampling frequency) with a fully-automated measuring system. The experimental site was fertilised with different nitrogen (N) fertilisers applied at 170kgNha–1, namely conventional urea (Urea), urea with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), polymer-coated urea (PCU), and urea with the nitrification inhibitor nitrapyrin (Nitrapyrin). Nitrous oxide emissions were highly episodic and mainly controlled by heavy rainfall events within two months of planting and fertiliser N application. Annual N2O emissions in the four treatments amounted to 2.31, 0.40, 0.69 and 1.58kgN2O-Nha–1year–1 for Urea, DMPP, PCU and Nitrapyrin treatments, respectively, while unfertilised plots produced an average of 0.16kgN2O-Nha–1year–1. Two of the tested products (DMPP and PCU) were found to be highly effective, decreasing annual N2O losses by 83% and 70%, respectively, but did not affect yield or NUE. This study shows that EEFs have a high potential to decrease N2O emissions from sub-tropical cereal cropping systems. More research is needed to assess if the increased costs of EEFs can be compensated by lower fertiliser application rates and/or yield increases.

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Greenhouse gas emissions from dung, urine and dairy pond sludge applied to pasture. 1. Nitrous oxide emissions

Animal Production Science ◽

10.1071/an15595 ◽

2018 ◽

Vol 58 (6) ◽

pp. 1087 ◽

Cited By ~ 7

Author(s):

G. N. Ward ◽

K. B. Kelly ◽

J. W. Hollier

Keyword(s):

Nitrous Oxide ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Nitrification Inhibitor ◽

Emission Factors ◽

Nitrous Oxide Emissions ◽

Cow Dung ◽

N2o Emissions ◽

Active Ingredients ◽

Gas Emissions

Nitrous oxide (N2O) from excreta deposited by grazing ruminants is a major source of greenhouse gas emissions in Australia. Experiments to measure N2O emissions from dairy cow dung, urine and pond sludge applied to pasture, and the effectiveness of the nitrification inhibitor nitrapyrin in reducing these emissions, were conducted in south-western Victoria, Australia. In Experiment 1, emissions from urine, with and without nitrapyrin, and from dung were measured. Treatments applied in September 2013 resulted in cumulative emissions (245 days) of 0.60, 5.35, 4.15 and 1.02 kg N2O-nitrogen (N)/ha for the nil, urine (1000 kg N/ha), urine (1000 kg N/ha) + nitrapyrin (1 kg active ingredients/ha), and dung (448 kg N/ha) treatments, respectively, giving emission factors of 0.47% and 0.09% for urine and dung respectively. Nitrapyrin reduced N2O emissions from urine for 35 days, with an overall reduction in emissions of 25%. In Experiment 2, sludge, with and without nitrapyrin, was applied in May 2014, and dung was applied in May, August, November 2014 and January 2015. Cumulative emissions (350 days) were 0.19, 0.49, 0.31 and 0.39 kg N2O-N/ha for the nil, sludge (308 kg N/ha), sludge (308 kg N/ha) + nitrapyrin (1 kg active ingredients/ha), and dung (total 604 kg N/ha) treatments, respectively, giving emission factors of 0.10% and 0.03% for sludge and dung. Nitrapyrin reduced N2O emissions from sludge for 60 days, with an overall reduction in emissions of 59%. A third experiment on two soil types compared emissions from urine and dung, with and without nitrapyrin, applied in different seasons of the year. Emissions were highly seasonal and strongly related to soil water status. Emission factors (90 days) ranged from 0.02% to 0.19% for urine and 0.01% to 0.12% for dung. Nitrapyrin reduced emissions from urine by 0–35% and had little effect on emissions from dung. Overall, the experiments found that nitrapyrin was an effective tool in reducing emissions from urine, dung and sludge applied to pasture, but the magnitude varied across the year, with nitrapyrin being most effective when soils had >70% water-filled pore space when major emissions occurred.

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Nitrous oxide emissions with enhanced efficiency and conventional urea fertilizers in winter wheat

Nutrient Cycling in Agroecosystems ◽

10.1007/s10705-021-10118-9 ◽

2021 ◽

Author(s):

Haibo An ◽

Jen Owens ◽

Brian Beres ◽

Yuejin Li ◽

Xiying Hao

Keyword(s):

Nitrous Oxide ◽

Winter Wheat ◽

Nitrification Inhibitor ◽

Field Trials ◽

Early Spring ◽

Nitrous Oxide Emissions ◽

Nitrification Inhibitors ◽

Late Fall ◽

Coated Urea ◽

Polymer Coated Urea

AbstractOptimizing nitrogen fertilizer management can reduce nitrous oxide (N2O) emissions. This study tested if split applying enhanced efficiency fertilizers (EEFs) resulted in lower N2O emissions than applying equivalent rates of urea at planting. In semiarid southern Alberta, field trials were conducted during three years (planting to harvest) in rainfed winter wheat crops. Annual fertilizer rates ranged from 146 to 176 kg N ha−1. Fertilizer types were urea, and three EEFs (polymer-coated urea, urea with urease and nitrification inhibitors, and urea with a nitrification inhibitor). Each fertilizer type was applied three ways: 100% banded at planting, split applied 30% banded at planting and 70% broadcast in late fall, and split applied 30% banded at planting and 70% broadcast at Feekes growth stage 4 (GS4, post-tiller formation, wheat entering the greening up phase in the early spring). Nitrous oxide was measured using static chambers between sub-weekly and monthly from planting to harvest. Over three years, cumulative N2O emissions ranged from 0.16 to 1.32 kg N ha−1. This was equivalent to emissions factors between 0.009 and 0.688%. Cumulative N2O emissions and emissions factors did not differ between fertilizer types, but they were lower when fertilizer was split applied at GS4 compared to in late fall (P ≤ 0.10). Our study suggests that EEFs do not reduce N2O emissions from rainfed winter wheat crops, but a well-timed split application with a majority of fertilizer applied after winter can minimize N2O emissions.

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Gaseous nitrogen losses from pig slurry fertilisation: can they be reduced with additives in a wheat crop?

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2021193-17271 ◽

2021 ◽

Vol 19 (3) ◽

pp. e0302

Author(s):

Noemí Mateo-Marín ◽

Ramón Isla ◽

Dolores Quílez

Keyword(s):

Nitrous Oxide ◽

Nitrification Inhibitor ◽

Nitrous Oxide Emissions ◽

Wheat Crop ◽

N2o Emissions ◽

Pig Slurry ◽

Gaseous Nitrogen ◽

N Losses ◽

Ammonia Volatilisation ◽

Irrigated Wheat

Aim of the study: The use of pig slurry as fertiliser is associated with gaseous nitrogen (N) losses, especially ammonia (NH3) and nitrous oxide (N2O), leading to environmental problems and a reduction of its fertiliser value. This study evaluates, in an irrigated wheat crop, the effect of different additives mixed with pig slurry to decrease NH3 and N2O losses.Area of study: Middle Ebro valley, SpainMaterials and methods: The treatments were: i) non-N-fertilised control, ii) pig slurry (PS), iii) pig slurry with the urease inhibitor monocarbamide dihydrogen sulphate (PS-UI), iv) pig slurry with a microbial activator in development (PS-A), and v) pig slurry with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (PS-NI). Pig slurry was applied at a target rate of 120 kg NH4+-N ha-1. Ammonia volatilisation was measured using semi-opened static chambers after treatments application at presowing 2016 and side-dressing 2017. Nitrous oxide emissions were measured using static closed chambers after treatments application at the 2017 and 2018 side-dressing.Main results: Ammonia volatilisation was estimated to be 7-9% and 19-23% of NH4+-N applied after presowing and side-dressing applications, respectively. Additives were not able to reduce NH3 emissions in any application moment. PS-NI was the only treatment being effective in reducing N2O emissions, 70% respect to those in PS treatment. Crop yield parameters were not affected by the application of the additives because of the no effect of additives controlling NH3 losses and the low contribution of N2O losses to the N balance (<1 kg N2O-N ha-1).Research highlights: The use of 3,4-dimethylpyrazole phosphate would be recommended from an environmental perspective, although without grain yield benefits.

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Mitigation of nitrous oxide emissions from furrow-irrigated Vertosols by 3,4-dimethyl pyrazole tetra-methylene sulfone, an alternative nitrification inhibitor to nitrapyrin for direct injection with anhydrous ammonia

Soil Research ◽

10.1071/sr18114 ◽

2018 ◽

Vol 56 (7) ◽

pp. 752

Author(s):

Graeme Schwenke ◽

Annabelle McPherson

Keyword(s):

Nitrous Oxide ◽

Direct Injection ◽

Nitrification Inhibitor ◽

Environmental Benefits ◽

Nitrous Oxide Emissions ◽

Future Research ◽

N2o Emissions ◽

Cotton Production ◽

Anhydrous Ammonia ◽

High Yields

Nitrogen (N) fertiliser inputs for irrigated cotton production are rapidly increasing to support ever-increasing yields, but much of the applied N may be lost as N gases, including nitrous oxide (N2O), via denitrification in medium–heavy clay soils. The addition of a nitrification inhibitor can reduce overall N loss and N2O emissions. Currently, nitrapyrin (2-chloro-6-trichloro methyl pyridine) is the only inhibitor used with anhydrous ammonia (AA), whereas 3,4-dimethyl pyrazole phosphate (DMPP) has potentially greater stability and longevity in soil, but is not compatible with AA. A newly-developed formulation based on DMPP, 3,4-dimethyl pyrazole tetra-methylene sulfone (DMPS), can be direct-injected with AA. We compared N2O emissions from DMPS- and nitrapyrin-treated AA from two Vertosols used for irrigated cotton. At Emerald (Queensland), both inhibitors reduced N2O emitted by 77% over 2 months. At Gunnedah (New South Wales), DMPS was active in the soil for 3 months, reducing N2O by 86%, whereas nitrapyrin activity lasted for 2 months and reduced N2O by 65%. Realising the potential for improved environmental benefits from directly injecting DMPS with AA requires an agronomic benefit justifying its additional cost to the farmer. Future research needs to investigate the potential for reduced N rates when using these inhibitors – without compromising high yields.

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Influence of enhanced efficiency fertilisation techniques on nitrous oxide emissions and productivity response from urea in a temperate Australian ryegrass pasture

Soil Research ◽

10.1071/sr15317 ◽

2016 ◽

Vol 54 (5) ◽

pp. 523 ◽

Cited By ~ 11

Author(s):

H. C. Suter ◽

H. Sultana ◽

R. Davies ◽

C. Walker ◽

D. Chen

Keyword(s):

Nitrous Oxide ◽

Gibberellic Acid ◽

Fine Particle ◽

Nitrification Inhibitor ◽

Biomass Productivity ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Urease Inhibitor ◽

Agronomic Efficiency ◽

Low Emission

The effect of a nitrification inhibitor on nitrous oxide (N2O) emissions across seasons, the effect of a urease inhibitor and a fine particle spray (both targeting ammonia (NH3) loss) on N2O emissions, and the potential for productivity benefits and efficiencies by using these enhanced efficiency fertilisers (EEFs) were investigated in temperate pastures. The study compared three treatments over an eight month period (April to December 2010): (1) urea (U), (2) urea with a nitrification inhibitor (3,4-dimethylpyrazole phosphate) (DMPP), and (3) urea with a urease inhibitor (N-(n-butyl) thiophosphoric triamide (NBTPT)) (GU). In autumn, when NH3 loss was predicted to be high, the effect of urea applied as a fine particle spray (containing urea, NBTPT and gibberellic acid (10g ha–1)) (FPA) on N2O emissions and productivity was determined. N2O emissions from urea applied to pastures were low, and were larger in spring than autumn due to soil moisture and temperature. DMPP was an effective tool for mitigating N2O emissions, decreasing fertiliser-induced N2O emissions relative to urea by 76% over eight months. However, the urease inhibitor (NBTPT) (GU) increased N2O emissions from urea by 153% over eight months. FPA had no impact on N2O, but was only examined during periods of low emission (autumn). No significant biomass productivity, agronomic efficiency benefits, or improvements in apparent fertiliser recovery were observed with the DMPP and GU treatments. A significant biomass productivity benefit was observed with the FPA treatment 55 days after fertiliser was applied, most likely because of the gibberellic acid. The outcomes highlight that although DMPP effectively decreased N2O emissions it had no impact on biomass productivity compared with urea. The use of the GU increased N2O emissions by preserving NH3 in the soil. To avoid this a lower rate of N should be applied with the urease inhibitor.

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Reducing nitrous oxide emissions from grazed winter forage crops

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2012.74.2884 ◽

2012 ◽

pp. 57-62 ◽

Cited By ~ 3

Author(s):

T.J. Van der Weerden ◽

T.M. Styles

Keyword(s):

Nitrous Oxide ◽

Soil Compaction ◽

Nitrification Inhibitor ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Nitrification Inhibitors ◽

Gaseous Emissions ◽

Forage Crops ◽

Compacted Soils ◽

Compacted Soil

Wintering cows on forage crops leads to urine being excreted onto wet, compacted soils. This is likely to result in significant gaseous emissions of nitrous oxide (N2O), which may be reduced through strategic applications of nitrification inhibitors. A study was established on a winter swede crop to (i) determine N2O emissions from compacted soil treated with cattle urine, and (ii) quantify the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in reducing these emissions. Nitrous oxide emissions from the urine + compacted soil were significantly greater (P < 0.001) than from compacted soil without urine, with 3.2% of the urine-N being lost as N2O. DCD application significantly reduced this loss (P < 0.05) to 0.8% of the applied urine-N. Expressed at a paddock scale, total N2O emissions from the winter-grazed swede crop were 7.9 kg N ha-1, which was reduced to 3.4 kg N ha-1 when DCD was applied. Keywords: urine, dicyandiamide, nitrification inhibitor, soil compaction, nitrous oxide.

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Urea-induced nitrous oxide emissions under sub-tropical rain-fed sorghum and sunflower were nullified by DMPP, partially mitigated by polymer-coated urea, or enhanced by a blend of urea and polymer-coated urea

Soil Research ◽

10.1071/sr18285 ◽

2019 ◽

Vol 57 (4) ◽

pp. 342 ◽

Cited By ~ 2

Author(s):

G. D. Schwenke ◽

B. M. Haigh

Keyword(s):

Nitrous Oxide ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

N Availability ◽

Soil N ◽

Total N ◽

Degradable Polymer ◽

Coated Urea ◽

Polymer Coated Urea ◽

The Impact

Delaying the accumulation of soil nitrate from urea applied at sowing should mitigate nitrous oxide (N2O) emissions without compromising optimum crop production. This delay may be achieved chemically using a nitrification inhibitor such as 3,4 dimethylpyrazole phosphate (DMPP), or physically by coating urea with a degradable polymer (PCU). In five field experiments across three summers, the impact of DMPP-coated urea applied at sowing on soil mineral nitrogen (N), N2O emissions and yields of grain sorghum or sunflower grown on sub-tropical Vertosols was assessed. At two experiments, DMPP effects on plant N uptake, soil N movement and total N loss were determined with 15N. One experiment included PCU and several blends: urea+DMPP-urea; urea+PCU; urea+DMPP-urea+PCU. Averaged across all experiments, DMPP reduced cumulative N2O emitted by 92% (range: 65–123%) and N2O emission factor (EF: percent of applied N emitted) by 88%. There was no statistical difference in N2O emitted between the 0N control and DMPP-urea. PCU reduced N2O emitted by 27% and EF by 34%. The urea+DMPP-urea blend also nullified urea-induced N2O, but urea+PCU increased N2O emissions and decreased grain yield due to a mismatch between soil N availability and plant N demand. DMPP arrested 15N movement in soil and reduced total 15N loss from 35% to 15% at one of the two 15N experiments. Applying DMPP-urea at sowing is an effective N strategy that nullifies urea-induced N2O emissions, maintains crop yield, and retains N in the soil–plant system. Negative impacts of the PCU+urea blend highlight the influence of growing season conditions on fertiliser N release.

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