Simulation of N2O emissions and mitigation options for rainfed wheat cropping on a Vertosol in the subtropics

The Water and Nitrogen Management Model (WNMM) was applied to simulate nitrous oxide (N2O) emissions from a wheat-cropped Vertosol under long-term management of no-till, crop residue retention, and nitrogen (N) fertiliser application in southern Queensland, Australia, from July 2006 to June 2009. For the simulation study, eight treatments of combinations of conventional tillage (CT) or no-till (NT), stubble burning (SB) or stubble retention (SR), and N fertiliser application at nil (0N) or 90 (90N) kg N/ha.year were used. The results indicated that WNMM satisfactorily simulated the soil water content of the topsoil, mineral N content of the entire soil profile (0–1.5 m), and N2O emissions from the soil under the eight treatments, compared with the corresponding field measurements. For simulating daily N2O emissions from soil, WNMM performed best for the treatment CT-SB-90N (R2 = 0.48, P < 0.001; RMSE = 10.2 g N/ha.day) and worst for the treatment CT-SB-0N (R2 = 0.03, P = 0.174; RMSE = 1.2 g N/ha.day). WNMM predicted N2O emissions from the soil more accurately for the fertilised treatments (i.e. 90N v. 0N), and for the residue retained treatments (SR v. SB). To reduce N2O emissions from the no-till and fertilised treatments, three scenarios were examined: application of nitrification inhibitor, application of controlled-release fertiliser, and deep placement of liquid fertiliser (UAN32). Only the deep placement of UAN32 below the 35 cm depth was effective, and could reduce the N2O emissions from the soil by almost 40%.

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

Soil Research ◽

10.1071/sr17022 ◽

2017 ◽

Vol 55 (6) ◽

pp. 547 ◽

Cited By ~ 9

Author(s):

Terry J. Rose ◽

Stephen G. Morris ◽

Peter Quin ◽

Lee J. Kearney ◽

Stephen Kimber ◽

...

Keyword(s):

Nitrous Oxide ◽

Nitrification Inhibitor ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Aerobic Rice ◽

Growing Period ◽

Tropical Environments ◽

Peak Flux ◽

Coated Urea ◽

Fertiliser Application

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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Soil nitrogen dynamics in irrigated maize systems as impacted on by nitrogen and stubble management

Australian Journal of Experimental Agriculture ◽

10.1071/ea06098 ◽

2008 ◽

Vol 48 (3) ◽

pp. 382 ◽

Cited By ~ 5

Author(s):

R. B. Edis ◽

D. Chen ◽

G. Wang ◽

D. A. Turner ◽

K. Park ◽

...

Keyword(s):

Nitrous Oxide ◽

Soil Nitrogen ◽

Field Measurements ◽

N2o Emission ◽

N Recovery ◽

Mineral N ◽

N Transformations ◽

Ammonium Thiosulfate ◽

Stubble Retention ◽

The Difference

The soil nitrogen (N) dynamics of an irrigated maize system in which stubble retention and stubble burned treatments were superimposed over treatments of varying N fertiliser rate were studied. The field site was near Whitton, New South Wales, Australia, and the work described here is part a life cycle analysis of greenhouse gas emissions from maize project. The objective of this part of the work was to quantify the fate of fertiliser N applied at the site. Field measurements of denitrification, mineral N content and recovery of 15N-labelled urea from microplots with and without ammonium thiosulfate were complimented with laboratory studies of denitrification and nitrous oxide (N2O) flux. Significantly (P < 0.05) more fertiliser N was recovered in the grain from the stubble incorporated treatment than the stubble burned treatment and there was greater recovery of fertiliser N in the soil at the end of the experiment in the stubble burned treatment. This may indicate that fertiliser N applied to the stubble burned system may be more exposed to soil-N transformations. The reason for the difference in uptake and soil residual is not clear but may be related to soil structure differences leading to less plant accessibility of N in the burned treatment. This difference may lead to more nitrous oxide emission from soil in the stubble burned treatments. Short-term (1 h) static chamber measurements in the field found a strong N-rate dependence of N2O emission rate for fertiliser rates between 0 and 300 kg N/ha. Inclusion of ammonium thiosulfate in the fertiliser formulation did not appear to have a significant impact on fertiliser N recovery.

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Greenhouse gas (N2O and CH4) fluxes under nitrogen-fertilised dryland wheat and barley on subtropical Vertosols: risk, rainfall and alternatives

Soil Research ◽

10.1071/sr15338 ◽

2016 ◽

Vol 54 (5) ◽

pp. 634 ◽

Cited By ~ 13

Author(s):

Graeme D. Schwenke ◽

David F. Herridge ◽

Clemens Scheer ◽

David W. Rowlings ◽

Bruce M. Haigh ◽

...

Keyword(s):

N Uptake ◽

Nitrification Inhibitor ◽

N2o Emission ◽

N2o Emissions ◽

Soil Mineral N ◽

Soil Mineral ◽

Mineral N ◽

Before And After ◽

Ch4 Uptake ◽

Crop N Uptake

The northern Australian grains industry relies on nitrogen (N) fertiliser to optimise yield and protein, but N fertiliser can increase soil fluxes of nitrous oxide (N2O) and methane (CH4). We measured soil N2O and CH4 fluxes associated with wheat (Triticum aestivum) and barley (Hordeum vulgare) using automated (Expts 1, 3) and manual chambers (Expts 2, 4, 5). Experiments were conducted on subtropical Vertosol soils fertilised with N rates of 0–160kgNha–1. In Expt 1 (2010), intense rainfall for a month before and after sowing elevated N2O emissions from N-fertilised (80kgNha–1) wheat, with 417gN2O-Nha–1 emitted compared with 80g N2O-Nha–1 for non-fertilised wheat. Once crop N uptake reduced soil mineral N, there was no further treatment difference in N2O. Expt 2 (2010) showed similar results, however, the reduced sampling frequency using manual chambers gave a lower cumulative N2O. By contrast, very low rainfall before and for several months after sowing Expt 3 (2011) resulted in no difference in N2O emissions between N-fertilised and non-fertilised barley. N2O emission factors were 0.42, 0.20 and –0.02 for Expts 1, 2 and 3, respectively. In Expts 4 and 5 (2011), N2O emissions increased with increasing rate of N fertiliser. Emissions were reduced by 45% when the N fertiliser was applied in a 50:50 split between sowing and mid-tillering, or by 70% when urea was applied with the nitrification inhibitor 3,4-dimethylpyrazole-phosphate. Methane fluxes were typically small and mostly negative in all experiments, especially in dry soils. Cumulative CH4 uptake ranged from 242 to 435g CH4-Cha–1year–1, with no effect of N fertiliser treatment. Considered in terms of CO2 equivalents, soil CH4 uptake offset 8–56% of soil N2O emissions, with larger offsets occurring in non-N-fertilised soils. The first few months from N fertiliser application to the period of rapid crop N uptake pose the main risk for N2O losses from rainfed cereal cropping on subtropical Vertosols, but the realisation of this risk is dependent on rainfall. Strategies that reduce the soil mineral N pool during this time can reduce the risk of N2O loss.

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Impact of earthworm <i>Lumbricus terrestris</i> living sites on the greenhouse gas balance of no-till arable soil

Biogeosciences ◽

10.5194/bg-12-5481-2015 ◽

2015 ◽

Vol 12 (18) ◽

pp. 5481-5493 ◽

Cited By ~ 21

Author(s):

M. Nieminen ◽

T. Hurme ◽

J. Mikola ◽

K. Regina ◽

V. Nuutinen

Keyword(s):

Greenhouse Gas ◽

Co2 Emissions ◽

Field Measurements ◽

Lumbricus Terrestris ◽

N2o Emission ◽

N2o Emissions ◽

Consistent Difference ◽

Climatic Effects ◽

Greenhouse Gas Balance ◽

No Till

Abstract. We studied the effect of the deep-burrowing earthworm Lumbricus terrestris on the greenhouse gas (GHG) fluxes and global warming potential (GWP) of arable no-till soil using both field measurements and a controlled 15-week laboratory experiment. In the field, the emissions of nitrous oxide (N2O) and carbon dioxide (CO2) were on average 43 and 32 % higher in areas occupied by L. terrestris (the presence judged by the surface midden) than in adjacent, unoccupied areas (with no midden). The fluxes of methane (CH4) were variable and had no consistent difference between the midden and non-midden areas. Removing the midden did not affect soil N2O and CO2 emissions. The laboratory results were consistent with the field observations in that the emissions of N2O and CO2 were on average 27 and 13 % higher in mesocosms with than without L. terrestris. Higher emissions of N2O were most likely due to the higher content of mineral nitrogen and soil moisture under the middens, whereas L. terrestris respiration fully explained the observed increase in CO2 emissions in the laboratory. In the field, the significantly elevated macrofaunal densities in the vicinity of middens likely contributed to the higher emissions from areas occupied by L. terrestris. The activity of L. terrestris increased the GWP of field and laboratory soil by 50 and 18 %, but only 6 and 2 % of this increase was due to the enhanced N2O emission. Our results suggest that high N2O emissions commonly observed in no-till soils can partly be explained by the abundance of L. terrestris under no-till management and that L. terrestris can markedly regulate the climatic effects of different cultivation practises.

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Comparison of grain yields and N2O emissions on Oxisol and Vertisol soils in response to fertiliser N applied as urea or urea coated with the nitrification inhibitor 3,4-dimethylpyrazole phosphate

Soil Research ◽

10.1071/sr15336 ◽

2016 ◽

Vol 54 (5) ◽

pp. 552 ◽

Cited By ~ 16

Author(s):

Massimiliano De Antoni Migliorati ◽

Mike Bell ◽

David Lester ◽

David W. Rowlings ◽

Clemens Scheer ◽

...

Keyword(s):

Grain Yield ◽

Crop Yields ◽

Cropping Systems ◽

Nitrification Inhibitor ◽

Measuring System ◽

Yield Response ◽

N2o Emissions ◽

North East ◽

Fertiliser Application ◽

N Rates

The potential for elevated nitrous oxide (N2O) losses is high in subtropical cereal cropping systems in north-east Australia, where the fertiliser nitrogen (N) input is one single application at or before planting. The use of urea coated with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) has been reported to substantially decrease N2O emissions and increase crop yields in humid, high-intensity rainfall environments. However, it is still uncertain whether this product is similarly effective in contrasting soil types in the cropping region of north-east Australia. In this study the grain yield response of sorghum (Sorghum bicolor L. Moench) to rates of fertiliser N applied as urea or urea coated with DMPP were compared in crops grown on a Vertisol and an Oxisol in southern Queensland. Seasonal N2O emissions were monitored on selected treatments for the duration of the cropping season and the early stages of a subsequent fallow period using a fully automated high-frequency greenhouse gas measuring system. On each soil the tested treatments included an unfertilised control (0kgNha–1) and two fertilised treatments chosen on the basis of delivering at least 90% of seasonal potential grain yield (160 and 120kgNha–1 on the Vertisol and Oxisol respectively) or at a common (suboptimal) rate at each site (80kgNha–1). During this study DMPP had a similar impact at both sites, clearly inhibiting nitrification for up to 8 weeks after fertiliser application. Despite the relatively dry seasonal conditions during most of the monitoring period, DMPP was effective in abating N2O emissions on both soils and on average reduced seasonal N2O emissions by 60% compared with conventional urea at fertiliser N rates equivalent to those producing 90% of site maximum grain yield. The significant abatement of N2O emissions observed with DMPP, however, did not translate into significant yield gains or improvements in agronomic efficiencies of fertiliser N use. These results may be due to the relatively dry growing season conditions before the bulk of crop N acquisition, which limited the exposure of fertiliser N to large losses due to leaching and denitrification.

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Yield, water productivity and economic return of dryland wheat in the Loess Plateau in response to conservation tillage practices

The Journal of Agricultural Science ◽

10.1017/s0021859617000338 ◽

2017 ◽

Vol 155 (8) ◽

pp. 1272-1286

Author(s):

Z. LI ◽

Q. ZHANG ◽

Q. YANG ◽

X. YANG ◽

J. LI ◽

...

Keyword(s):

Winter Wheat ◽

Grain Yield ◽

Loess Plateau ◽

Conservation Tillage ◽

Water Productivity ◽

Conventional Tillage ◽

The Loess Plateau ◽

Tillage Practices ◽

Stubble Retention ◽

No Till

SUMMARYWinter wheat (Triticum aestivum L.) production on the Loess Plateau in China has been threatened by water scarcity and climate change during the last decade. Sustainable crop production in this region requires managerial practices that can provide high yield and high water productivity (WP). A 7-year (2001–2008) study at the Loess Plateau Research Station of Lanzhou University investigated the effects of various conservation tillage practices on grain yield, soil water content (SWC), WP and economic return of winter wheat production. Tillage treatments included: conventional tillage (T), conventional tillage followed by stubble retention (TS), no-till (NT) and no-till followed by stubble retention (NTS). Over the entire experimental period, grain yield and WP of winter wheat ranged from 1279 to 4894 kg/ha and 0·32 to 2·41 kg/m3, respectively. Both were significantly affected by tillage treatment and year, while SWC was only affected by year. Grain yield and WP in TS was increased by 4·9, 12·1, 0·9% and 13·7, 20·4 and 3·9% compared with NTS, NT and T, respectively, over seven growing seasons. Additionally, a multiple linear regression analysis indicated that grain yield is mainly limited by SWC during planting. Despite its lower grain yield, the NTS treatment increased economic benefit by US$ 328, US$ 23 and US$ 87/ha compared with TS, NT and T, respectively. Therefore, it is suggested that increasing soil water storage at wheat sowing time and encouraging the use of NTS could improve economic returns in this region.

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Earthworm impact on the global warming potential of a no-tillage arable soil

Biogeosciences Discussions ◽

10.5194/bgd-12-6325-2015 ◽

2015 ◽

Vol 12 (8) ◽

pp. 6325-6359

Author(s):

M. Nieminen ◽

T. Hurme ◽

J. Mikola ◽

K. Regina ◽

V. Nuutinen

Keyword(s):

Global Warming ◽

Co2 Emissions ◽

Global Warming Potential ◽

Field Measurements ◽

N2o Emission ◽

N2o Emissions ◽

Consistent Difference ◽

No Tillage ◽

Climatic Effects ◽

No Till

Abstract. We studied the effect of the deep-burrowing earthworm Lumbricus terrestris on the greenhouse gas (GHG) fluxes and global warming potential (GWP) of arable no-till soil using both field measurements and a controlled 15 week laboratory experiment. In the field, the emissions of nitrous oxide (N2O) and carbon dioxide (CO2) were on average 43 and 32% higher in areas occupied by L. terrestris (the presence judged by the surface midden) than in adjacent, unoccupied areas (with no midden). The fluxes of methane (CH4) were variable and had no consistent difference between the midden and non-midden areas. Removing the midden did not affect soil N2O and CO2 emissions. The laboratory results were consistent with the field observations in that the emissions of N2O and CO2 were on average 27 and 13% higher in mesocosms with than without L. terrestris. Higher emissions of N2O were most likely due to the higher content of mineral nitrogen and soil moisture under the middens, whereas L. terrestris respiration fully explained the observed increase in CO2 emissions. The activity of L. terrestris increased the GWP of field and laboratory soil by 50 and 18%, but only 6 and 2% of this increase was due to the enhanced N2O emission. Our results suggest that high N2O emissions commonly observed in no-tillage soils can partly be explained by the abundance of L. terrestris under no-till management and that L. terrestris can markedly regulate the climatic effects of different cultivation practises.

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Nitrate Leaching to a Shallow Mid-Atlantic Coastal Plain Aquifer as Influenced by Conventional No-Till and Low-Input Sustainable Grain Production Systems

Water Science & Technology ◽

10.2166/wst.1993.0475 ◽

1993 ◽

Vol 28 (3-5) ◽

pp. 691-700 ◽

Cited By ~ 7

Author(s):

J. P. Craig ◽

R. R. Weil

Keyword(s):

Management Practices ◽

Production Systems ◽

Cropping Systems ◽

Cropping System ◽

Atlantic Coastal Plain ◽

Grain Production ◽

Nitrogen And Phosphorus ◽

Mineral N ◽

Low Input ◽

No Till

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.

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Corn Forage Production in No‐Till and Conventional Tillage Double‐Cropping Systems 1

Agronomy Journal ◽

10.2134/agronj1977.00021962006900040029x ◽

1977 ◽

Vol 69 (4) ◽

pp. 635-638 ◽

Cited By ~ 3

Author(s):

L. R. Nelson ◽

R. N. Gallaher ◽

M. R. Holmes ◽

R. R. Bruce

Keyword(s):

Cropping Systems ◽

Conventional Tillage ◽

Forage Production ◽

Double Cropping ◽

No Till

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Effect of Tillage Systems on Soil Organic Carbon and Soil Quality in a Purple Paddy Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.1190 ◽

2011 ◽

Vol 183-185 ◽

pp. 1190-1194

Author(s):

Jun Ke Zhang ◽

Qing Ju Hao ◽

Chang Sheng Jiang ◽

Yan Wu

Keyword(s):

Organic Carbon ◽

Soil Quality ◽

Paddy Soil ◽

Conventional Tillage ◽

Water Infiltration ◽

Purple Soil ◽

Tillage Systems ◽

Field Station ◽

No Till ◽

The Impact

The impact of conservation tillage practices on carbon sequestration has been of great interest in recent years. This experiment analyzed the organic carbon status of soils sampled at depth increments from 0 to 60 cm after 20 years in a purple paddy soil. The tillage experiment was established in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China, located in the farm of Southwest University (30°26′N, 106°26′E), Chongqing. In this paper, five tillage treatments including conventional tillage with rice only system (DP), conventional tillage with rotation of rice and rape system (SL), no-till and ridge culture with rotation of rice and rape system (LM), no-till and plain culture with rotation of rice and rape system (XM) and tillage and ridge culture with rotation of rice and rape system (LF) were selected as research objectives to measure SOC storage and stratification ratio of SOC (CSR). The SOC storage under different tillage systems was calculated based on an equivalent soil mass. The CSR can be used as an indicator of soil quality because surface organic matter is essential to erosion control, water infiltration, and the conservation of nutrients. Results showed that in soil under no-till SOC was concentrated near the surface, while in tilled soil SOC decreased equably with the increase of soil depth. The difference of SOC contents between the five tillage systems was the largest in the top soil and the lowest in the bottom soil. The order of SOC storage was LM (158.52 Mg C•ha-1) >DP (106.74 Mg C•ha-1) >XM (100.11 Mg C•ha-1) >LF (93.11 Mg C•ha-1) >SL (88.59 Mg C•ha-1), LM treatment was significantly higher than the other treatments. The CSR of 0-10/50-60 cm was 2.65, 2.70 and 2.14 under LM, XM and LF treatments, while 1.54 and 1.92 under DP and SL treatments. We considered CSR>2 indicate an improvement in soil quality produced by changing from tillage to no-tillage, as well as changing from plane to ridge. Overall, long-term LM treatment is a valid strategy for increasing SOC storage and improving soil quality in a purple paddy soil in Southwest China.

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