scholarly journals Soil N2O emissions after perennial legume termination in an alfalfa-wheat crop rotation system under Mediterranean conditions

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Laura Trozzo ◽  
Matteo Francioni ◽  
Ayaka Wenhong Kishimoto-Mo ◽  
Lucia Foresi ◽  
Michele Bianchelli ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Crop Residues ◽  
Block Design ◽  
N Uptake ◽  
Ghg Emissions ◽  
N2o Emission ◽  
Wheat Crop ◽  
N2o Emissions ◽  
Alfalfa Field ◽  
Perennial Legume

Agricultural activities are potential sources of greenhouse gas (GHG) emissions, and nitrous oxide (N2O) is one of the most important non-carbon-dioxide GHGs. Perennial legumes such as alfalfa (Medicago sativa L.) have potential roles for reduction of soil GHG emissions as part of crop rotation systems. However, the implications of perennial legume termination by tillage and subsequent soil incorporation of the residues for reduced GHG emissions have been poorly examined in Mediterranean environments. With the aim to assess the magnitude of soil N2O emissions (important for the definition of mitigation strategies) after perennial legume termination in alfalfa-wheat crop rotation systems in a Mediterranean environment, we defined the hypothesis that alfalfa termination by tillage with incorporation of the crop residues will increase soil N2O emissions during the subsequent wheat season. To test this hypothesis, closed static chambers were used in a field–plot experiment, using a complete randomised block design with three replicates. Soil N2O emissions were monitored across 33 sampling dates from October 2017 to July 2018, as a comparison between an original 6-year-old alfalfa field (‘continuous alfalfa’) and alfalfa termination followed by wheat (‘alfalfa+ wheat’). The soil N2O emission fluxes varied markedly across the treatments and throughout the monitoring period (from – 0.02±0.01 to 0.53±0.14 g N-N2O ha–1 h–1, and from 0.02±0.07 to 0.37±0.11 g N-N2O ha–1 h–1 for continuous alfalfa and alfalfa+wheat, respectively), generally following the changes in soil temperature. Several soil N2O emission peaks were recorded for both treatments, which mainly coincided with rainfall and with increased soil water content. In the 2 months following alfalfa termination, alfalfa+wheat showed higher cumulative weekly soil N2O emissions compared to continuous alfalfa. Following alfalfa termination for alfalfa+wheat, the increased cumulative weekly soil N2O emissions appeared to be due to asynchrony between nitrogen (N) released into the soil from mineralisation of the alfalfa residues and N uptake by the wheat. Despite these initial high soil N2O emissions for alfalfa+wheat, the seasonal cumulative soil N2O emissions were not significantly different (0.77±0.09 vs 0.85±0.18 kg N-N2O ha–1 for continuous alfalfa and alfalfa+wheat, respectively). These data suggest that legume perennial crop termination in alfalfa–wheat rotation systems does not lead to significant loss of N2O from the soil. The alfalfa termination by tillage performed in autumn might, on the one hand, have slowed the mineralisation process, and might, on the other hand, have synchronised the N release by the mineralised crop residues, with the N uptake by the wheat reducing the soil N2O emissions.

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

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

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 634 ◽  
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.

scholarly journals Analysis of N2O emissions and isotopomers to understand nitrogen cycling associated with multispecies grassland swards at a lysimeter scale

2020 ◽  
Author(s):  
Conor Bracken ◽  
Gary Lanigan ◽  
Karl Richards ◽  
Saoirse Tracy ◽  
Christoph Müller ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
White Clover ◽  
Block Design ◽  
N Uptake ◽  
Soil Microbial Communities ◽  
N Cycling ◽  
N2o Emissions ◽  
Total N ◽  
Transformation Pathways ◽  
Grass Growth

<p>Nitrous oxide (N<sub>2</sub>O) is a potent greenhouse gas associated with nitrogen fertiliser inputs to agricultural production systems. Minimising N<sub>2</sub>O emissions is important to improving the efficiency and sustainability of grassland agriculture. Multispecies grassland swards composed of plants from different functional groups (grasses, legumes, herbs) have been considered as a management strategy to achieve this goal. Numerous soil nitrogen transformation pathways can lead to the production of N<sub>2</sub>O emissions. These transformation pathways are regulated by soil microbial communities and the environmental conditions and management practices that impact on them. Much research has been carried out on N cycling and N<sub>2</sub>O emissions from predominantly grass monoculture systems. However, there is a lot yet to understand about how agricultural grasslands with diverse plant communities influence soil N cycling and N<sub>2</sub>O emissions. A lysimeter experiment was set up as a completely randomised block design and carried out over a full year to investigate N<sub>2</sub>O production, and nitrogen cycling associated with four sward types. The swards four swards were: perennial ryegrass (PRG, Lolium perenne); PRG and low white clover (PRG + LWC, Trifolium repens); PRG and high white clover (PRG + HWC); PRG, WC and ribwort plantain (PRG + WC + PLAN, Plantago lanceolata) managed at 250, 90, 0, and 45 kg N ha<sup>-1</sup>yr<sup>-1</sup>, respectively. Fertiliser N was applied by syringe as urea in splits at suitable timings to meet grass growth demands. N<sub>2</sub>O fluxes were measured using a static chamber technique and additional samples were taken after the final flux sample to measure the associated N<sub>2</sub>O isotopomers using a novel Cavity Ring Down Spectroscopy technique. Leachate volumes were measured on a weekly basis and composite monthly samples were used to determine the total amount of N leached from each treatment over the full year. Herbage was harvested on a monthly basis to measure DM yield (kg DM ha<sup>-1</sup>), total N (%) and N yield (kg N ha<sup>-1</sup>).This work reports on the N<sub>2</sub>O emissions and N leaching associated with the four sward treatments and related these N losses to the treatments DM yields and N uptake as an estimation of the efficiency of these differing grassland management strategies. N<sub>2</sub>O isotopomer measurements were used to indicate N transformation pathways driving N loss over the growing season particularly around periods of peak N<sub>2</sub>O emissions.</p>

scholarly journals Smallholder African farms in western Kenya have limited greenhouse gas fluxes

2015 ◽  
Vol 12 (18) ◽  
pp. 15301-15336 ◽  
Author(s):  
D. E. Pelster ◽  
M. C. Rufino ◽  
T. Rosenstock ◽  
J. Mango ◽  
G. Saiz ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Crop Production ◽  
Crop Yields ◽  
N Uptake ◽  
Ghg Emissions ◽  
Sub Saharan Africa ◽  
N2o Emissions ◽  
Vegetation Types ◽  
Western Kenya ◽  
The Impact

Abstract. Few field studies examine greenhouse gas (GHG) emissions from African agricultural systems resulting in high uncertainty for national inventories. We provide here the most comprehensive study in Africa to date, examining annual CO2, CH4 and N2O emissions from 59 plots, across different vegetation types, field types and land classes in western Kenya. The study area consists of a lowland area (approximately 1200 m a.s.l.) rising approximately 600 m to a highland plateau. Cumulative annual fluxes ranged from 2.8 to 15.0 Mg CO2-C ha−1, −6.0 to 2.4 kg CH4-C ha−1 and −0.1 to 1.8 kg N2O-N ha−1. Management intensity of the plots did not result in differences in annual fluxes for the GHGs measured (P = 0.46, 0.67 and 0.14 for CO2, N2O and CH4 respectively). The similar emissions were likely related to low fertilizer input rates (≤ 20 kg ha−1). Grazing plots had the highest CO2 fluxes (P = 0.005); treed plots were a larger CH4 sink than grazing plots (P = 0.05); while N2O emissions were similar across vegetation types (P = 0.59). This case study is likely representative for low fertilizer input, smallholder systems across sub-Saharan Africa, providing critical data for estimating regional or continental GHG inventories. Low crop yields, likely due to low inputs, resulted in high (up to 67 g N2O-N kg−1 aboveground N uptake) yield-scaled emissions. Improving crop production through intensification of agricultural production (i.e. water and nutrient management) may be an important tool to mitigate the impact of African agriculture on climate change.

scholarly journals Water regime affects soil N2O emission and tomato yield grown under different types of fertilisers

2017 ◽  
pp. 74-79 ◽  
Author(s):  
Luca Vitale ◽  
Anna Tedeschi ◽  
Franca Polimeno ◽  
Lucia Ottaiano ◽  
Giuseppe Maglione ◽  
...  
Keyword(s):  
Water Supply ◽  
Plant Biomass ◽  
N Uptake ◽  
Photochemical Efficiency ◽  
N2o Emission ◽  
Fruit Production ◽  
N2o Emissions ◽  
Mineral Fertiliser ◽  
N2o Fluxes ◽  
Reduced Water

Tomato plants were subjected to three fertilisation treatments (M: mineral fertiliser; DMPP: mineral fertiliser + 3,4- dimethylpyrazole phosphate; OM: NKP + organic animal manure) in combination with two water regimes (100% and 50% evapotranspiration). Plant biomass, fruit production, nitrogen use efficiency (NUE) and N uptake, maximal PSII photochemical efficiency, Fv/Fm and cumulative soil N2O emission were determined. Well-watered OM plants showed higher values of biomass, fruit production, NUE and N uptake than M and DMPP plants; cumulative N2O fluxes were lower in DMPP plots than in M and OM plots. The reduced water supply determined a drop in crop biomass, fruit production, NUE and N uptake, and cumulative N2O fluxes in M and OM treatments that were higher in OM plots, whereas it determined a significant rise in cumulative N2O fluxes in DMPP plots that was lower in absolute term compared to M and OM plots recorded under well-water irrigation. It can be concluded that DMPP added-fertiliser has a good performance in semiarid environment resulting a better nitrogen source compared to conventional and organo-mineral fertilisers under reduced water supply, able to preserve crop yield and to determine soil N2O emissions (as expressed in CO2 eq) not dangerous for global environment.

A comparison of chickpeas and pasture legumes for sustaining yields and nitrogen status of subsequent wheat

1997 ◽  
Vol 48 (3) ◽  
pp. 305 ◽  
Author(s):  
I. C. R. Holford ◽  
G. J. Crocker
Keyword(s):  
Protein Content ◽  
Crop Residues ◽  
N Uptake ◽  
Yield Potential ◽  
Wheat Crop ◽  
N Fixation ◽  
Soil N ◽  
Red Clay ◽  
Mineral N ◽  
Positive Effects

Six treatments were compared for their effects on wheat yields, nitrogen (N) uptake, protein content, and fertiliser N requirements in a long-term rotation study on a black earth and a red clay in northern New South Wales. Three of the treatments were lucerne, subterranean clover, and snail medic, all grown simultaneously from 1988 to 1990 and all followed by 3 years of wheat. The other 3 treatments were biennial rotations of chickpea–wheat and long-fallow–wheat as well as a continuous wheat monoculture, all lasting 6 years. With the exception of the first wheat crop, which experienced very low growing-season rainfall, lucerne was more beneficial than other legumes to following wheat crops in terms of yield, protein content, and fertiliser N requirement. Clover closely followed lucerne in the magnitude of its positive effects, whereas medic and chickpea produced much smaller effects. Because of the amount of N removed in the chickpea grain, it appeared that the small positive effects of chickpea were due to soil N sparing or rapid mineralisation from crop residues rather than any net contribution of N fixation to soil N accretion. Average yields of the 3 wheat crops following lucerne and clover were much higher than average yields 20 years previously following lucerne, even though average yields of continuously grown wheat have declined over the past 20 years. However, lucerne eliminated the need for N fertiliser for no more than 2 following wheat crops, and clover for only the first wheat crop. It appears that the longer duration of lucerne benefits reported in earlier studies was due to the higher background soil N levels as well as the lower yield potential in the earlier years. Nevertheless, lucerne lowered the fertiliser requirement of the third wheat crop by more than 50%. In contrast to lucerne, annual legumes are probably most beneficial if grown in alternate years with wheat. The large benefits of long fallowing particularly on the black earth were apparently caused by its enhancement of soil moisture and mineral N accumulation. However, these N effects were surprisingly large considering the degree of depletion of organic matter in long-fallowed soils.

scholarly journals Nitrogen Management in a Maize-Groundnut Crop Rotation of Humid Tropics: Effect on N2O Emission

2001 ◽  
Vol 1 ◽  
pp. 320-327
Author(s):  
M.I. Khalil ◽  
A.B. Rosenani ◽  
O. Van Cleemput ◽  
C.I. Fauziah ◽  
J. Shamshuddin
Keyword(s):  
Crop Rotation ◽  
Crop Residues ◽  
Pore Space ◽  
Residual Effect ◽  
N2o Emission ◽  
N Fertilizer ◽  
Chicken Manure ◽  
Mineral N ◽  
N Transformations ◽  
N Sources

Development of appropriate land management techniques to attain sustainability and increase the N use efficiency of crops in the tropics has been gaining momentum. The nitrous oxides (N2Os) affect global climate change and its contribution from N and C management systems is of great significance. Thus, N transformations and N2O emission during maize-groundnut crop rotation managed with various N sources were studied. Accumulation of nitrate (NO3 –) and its disappearance happened immediately after addition of various N sources, showing liming effect. The mineral N retained for 2–4 weeks depending on the type and amount of N application. The chicken manure showed rapid nitrification in the first week after application during the fallow period, leading to a maximum N2O flux of 9889 μg N2O-N m–2 day– 1. The same plots showed a residual effect by emitting the highest N2O (4053 μg N2O-N m–2 day– 1) during maize cultivation supplied with a halfrate of N fertilizer. Application of N fertilizer only or in combination with crop residues exhibited either lowered fluxes or caused a sink during the groundnut and fallow periods due to small availability of substrates and/or low water-filled pore space (<40%). The annual N2O emission ranged from 1.41 to 3.94 kg N2O-N ha–1; the highest was estimated from the chicken manure plus crop residues and half-rate of inorganic N-amended plots. Results indicates a greater influence of chicken manure on the N transformations and thereby N2O emission.

Does 3,4-dimethylpyrazole phosphate or N-(n-butyl) thiophosphoric triamide reduce nitrous oxide emissions from a rain-fed cropping system?

Soil Research ◽  
2018 ◽  
Vol 56 (3) ◽  
pp. 296 ◽  
Author(s):  
Guangdi D. Li ◽  
Graeme D. Schwenke ◽  
Richard C. Hayes ◽  
Hongtao Xing ◽  
Adam J. Lowrie ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Crop Yields ◽  
Cropping System ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Wheat Crop ◽  
N2o Emissions ◽  
Urease Inhibitors ◽  
Eastern Australia

Nitrification and urease inhibitors have been used to reduce nitrous oxide (N2O) emissions and increase nitrogen use efficiency in many agricultural systems. However, their agronomic benefits, such as the improvement of grain yield, is uncertain. A two-year field experiment was conducted to (1) investigate whether the use of 3,4-dimethylpyrazole phosphate (DMPP) or N-(n-butyl) thiophosphoric triamide (NBPT) can reduce N2O emissions and increase grain yield and (2) explore the financial benefit of using DMPP or NBPT in a rain-fed cropping system in south-eastern Australia. The experiment was conducted at Wagga Wagga, New South Wales, Australia with wheat (Triticum aestivum L.) in 2012 and canola (Brassica napus L.) in 2013. Results showed that urea coated with DMPP reduced the cumulative N2O emission by 34% for a wheat crop in 2012 (P < 0.05) and by 62% for a canola crop in 2013 (P < 0.05) compared with normal urea, but urea coated NBPT had no effect on N2O emission for the wheat crop in 2012. Neither nitrification nor urease inhibitors increased crop yields because the low rainfall experienced led to little potential for gross N loss through denitrification, leaching or volatilisation pathways. In such dry years, only government or other financial incentives for N2O mitigation would make the use of DMPP with applied N economically viable.

Towards a benchmarking tool for minimizing wastewater utility greenhouse gas footprints

2012 ◽  
Vol 66 (11) ◽  
pp. 2483-2495 ◽  
Author(s):  
L. Guo ◽  
J. Porro ◽  
K. R. Sharma ◽  
Y. Amerlinck ◽  
L. Benedetti ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Treatment Plant ◽  
N2o Emission ◽  
Mitigation Strategies ◽  
N2o Emissions ◽  
N2o Production ◽  
Average Value ◽  
And Control

A benchmark simulation model, which includes a wastewater treatment plant (WWTP)-wide model and a rising main sewer model, is proposed for testing mitigation strategies to reduce the system's greenhouse gas (GHG) emissions. The sewer model was run to predict methane emissions, and its output was used as the WWTP model input. An activated sludge model for GHG (ASMG) was used to describe nitrous oxide (N2O) generation and release in activated sludge process. N2O production through both heterotrophic and autotrophic pathways was included. Other GHG emissions were estimated using empirical relationships. Different scenarios were evaluated comparing GHG emissions, effluent quality and energy consumption. Aeration control played a clear role in N2O emissions, through concentrations and distributions of dissolved oxygen (DO) along the length of the bioreactor. The average value of N2O emission under dynamic influent cannot be simulated by a steady-state model subjected to a similar influent quality, stressing the importance of dynamic simulation and control. As the GHG models have yet to be validated, these results carry a degree of uncertainty; however, they fulfilled the objective of this study, i.e. to demonstrate the potential of a dynamic system-wide modelling and benchmarking approach for balancing water quality, operational costs and GHG emissions.

scholarly journals Nitrous Oxide Emission from Grazing Is Low across a Gradient of Plant Functional Diversity and Soil Conditions

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 223
Author(s):  
John Kormla Nyameasem ◽  
Carsten S. Malisch ◽  
Ralf Loges ◽  
Friedhelm Taube ◽  
Christof Kluß ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
N Uptake ◽  
N2o Emission ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Mineral N ◽  
Grazed Pastures ◽  
Growing Seasons ◽  
Nitrogen Inputs ◽  
Organically Managed

Nitrous oxide (N2O) emissions from pastures can vary significantly depending on soil and environmental conditions, nitrogen (N) input, as well as the plant’s ability to take up the N. We tested the hypothesis that legume-based N sources are characterized by significantly lower emission factors than mineral N based dairy systems. Therefore, this study monitored N2O emissions for a minimum of 100 days and up to two growing seasons across a gradient of plant species diversity. Emissions were measured from both grazed pastures and a controlled application of urine and dung using the static chamber method. About 90% of the simulated experiments’ accumulated N2O emissions occurred during the first 60–75 days. The average accumulated N2O emissions were 0.11, 0.87, 0.99, and 0.21 kg ha−1 for control, dung, urine patches, and grazed pastures, respectively. The N uptake efficiency at the excreta patch scale was about 70% for both dung and urine. The highest N2O-N emission factor was less than half compared with the IPCC default (0.3 vs. 0.77), suggesting an overestimation of N2O-N emissions from organically managed pastures in temperate climates. Plant diversity showed no significant effect on N2O emission. However, functional groups were significant (p < 0.05). We concluded that legume-containing pasture systems without a fertilizer addition generally appear capable of utilizing nitrogen inputs from excreta patches efficiently, resulting in low N2O emissions.

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