A comparison between vegetable intercropping systems and monocultures in greenhouse gas emissions under organic management

Author(s):  
Virginia Sánchez-Navarro ◽  
Mariano Marcos-Pérez ◽  
Raúl Zornoza

<p><strong>Legume crops have been proposed as a way of reducing greenhouse gas (GHG) emissions because both, their rhizosphere behaviour and their ability to fix atmospheric N reducing the need of external N fertilizer. Moreover, the establishment of organic agriculture has been proposed as a sustainable strategy to enhance the delivery of ecosystem services, including mitigation of climate change by decreases in GHG emissions and increases in soil C sequestration. The aim of this study was to assess the effect of the association between cowpea (Vigna unguiculata L.) and melon (Cucumis melo L.) growing in different </strong>intercropping patterns <strong>on soil CO<sub>2</sub> and N<sub>2</sub>O emissions compared to cowpea and melon monocultures </strong><strong>under organic management as a possible strategy for climate change mitigation. Soil </strong><strong>CO<sub>2</sub> and N<sub>2</sub>O</strong><strong> emissions were weekly measured in melon and cowpea rows using the dynamic chamber method during one cropping cycle in 2019. Results indicated that melon growing as monoculture was related to increases in </strong> <strong>O cumulative emissions (0.431 g m<sup>-2</sup>) compared to the average of the rest of treatments (0.036 g m<sup>-2</sup>). Cowpea growing as monoculture was related to decreases in </strong><strong>CO<sub>2</sub></strong> <strong>cumulative emissions (390 g m<sup>-2</sup>) compared with the other treatments (512 g m<sup>-2 </sup>average). However, N<sub>2</sub>O and </strong><strong>CO<sub>2</sub></strong><strong> emission patterns did not directly follow soil moisture patterns in the experimental period, with no significant correlations. Finally there were no significant differences among intercropping treatments with regard to NO<sub>2</sub> and </strong><strong>CO<sub>2 </sub></strong><strong>emissions. Further measurements are needed to monitor the evolution of GHG emissions under these cropping systems and confirm the trend observed</strong>.</p>

Soil Research ◽  
2016 ◽  
Vol 54 (2) ◽  
pp. 254 ◽  
Author(s):  
Eva Erhart ◽  
Harald Schmid ◽  
Wilfried Hartl ◽  
Kurt-Jürgen Hülsbergen

Compost fertilisation is one way to close material cycles for organic matter and plant nutrients and to increase soil organic matter content. In this study, humus, nitrogen (N) and energy balances, and greenhouse gas (GHG) emissions were calculated for a 14-year field experiment using the model software REPRO. Humus balances showed that compost fertilisation at a rate of 8 t/ha.year resulted in a positive balance of 115 kg carbon (C)/ha.year. With 14 and 20 t/ha.year of compost, respectively, humus accumulated at rates of 558 and 1021 kg C/ha.year. With mineral fertilisation at rates of 29–62 kg N/ha.year, balances were moderately negative (–169 to –227 kg C/ha.year), and a clear humus deficit of –457 kg C/ha.year showed in the unfertilised control. Compared with measured soil organic C (SOC) data, REPRO predicted SOC contents fairly well with the exception of the treatments with high compost rates, where SOC contents were overestimated by REPRO. GHG balances calculated with soil C sequestration on the basis of humus balances, and on the basis of soil analyses, indicated negative GHG emissions with medium and high compost rates. Mineral fertilisation yielded net GHG emissions of ~2000 kg CO2-eq/ha.year. The findings underline that compost fertilisation holds potential for C sequestration and for the reduction of GHG emissions, even though this potential is bound to level off with increasing soil C saturation.


Author(s):  
A.J. Parsons ◽  
J.S. Rowarth ◽  
P.C.D. Newton

There has been growing interest in including soil carbon (C) sequestration, as an offset to greenhouse gas (GHG) emissions, within New Zealand's commitment to the Kyoto Protocol, even though national trends report soil C concentrations in many areas is declining. There are different schools of thought as to what drives changes in soil C (e.g. grazing management, fertiliser inputs, species) and so in our capacity to increase the rate of sequestration of C since 1990 to gain C credits.


2021 ◽  
Vol 51 (1) ◽  
pp. 78-88
Author(s):  
Rachel A. Kendall ◽  
Karen A. Harper ◽  
David Burton ◽  
Kevin Hamdan

Forested wetlands may represent important ecosystems for mitigating climate change effects through carbon (C) sequestration because of their slow decomposition and C storage by trees. Despite this potential importance, few studies have acknowledged the role of temperate treed swamps in the C cycle. In southwestern Nova Scotia, Canada, we examined the role of treed swamps in the soil C cycle by determining C inputs through litterfall, assessing decomposition rates and soil C pools, and quantifying C outputs through soil greenhouse gas (GHG) emissions. The treed swamps were found to represent large supplies of C inputs through litterfall to the forest floor. The swamp soils had substantially greater C stores than the swamp–upland edge or upland soils. We found growing season C inputs via litterfall to exceed C outputs via GHG emissions in the swamps by a factor of about 2.5. Our findings indicate that temperate treed swamps can remain a C sink even if soil GHG emissions were to double, supporting conservation efforts to preserve temperate treed swamps as a measure to mitigate climate change.


2016 ◽  
Vol 34 (2) ◽  
pp. 277-284
Author(s):  
Hernando Criollo E. ◽  
Amanda Silva P. ◽  
Hernando Delgado H.

This research focused on the greenhouse gas (GHG) emissions and potential sinks associated with conventional and sustainable fruit production systems in the Highlands region of Pasto, Nariño, Colombia. Based on the IPCC (2006) methodologies, the annual emission balance for a 6-year production cycle included agricultural sources and gasoline consumption related to the main agricultural activities and the potential for soil C accumulation and biomass C fixation in all of the studied systems. The multivariate analysis showed that positive GHG balance emissions would be achieved in all sustainable fruit production systems, as compared to conventional fruit production systems with greater impact on (SS1): Rubusglaucus Benth. associated with Acacia decurrens trees and live coverage of kikuyu Pen-nisetum clandestinum grass. According to the results of this study, (SS1) showed the beneficial total GHG balance emission accounting for -21,079 kg of atmospheric CO2eq ha-1 yr-1 divided into -4,587 kg CO2eq ha-1 yr-1 and -17,102 kg CO2eq ha-1 yr-1 due an annual soil and biomass C sequestration potential that could help offset its emissions (610 kg CO2eq ha-1 yr-1).


2021 ◽  
Author(s):  
Sylvia Vetter ◽  
Michael Martin ◽  
Pete Smith

<p>Reducing greenhouse gas (GHG) emissions in to the atmosphere to limit global warming is the big challenge of the coming decades. The focus lies on negative emission technologies to remove GHGs from the atmosphere from different sectors. Agriculture produces around a quarter of all the anthropogenic GHGs globally (including land use change and afforestation). Reducing these net emissions can be achieved through techniques that increase the soil organic carbon (SOC) stocks. These techniques include improved management practices in agriculture and grassland systems, which increase the organic carbon (C) input or reduce soil disturbances. The C sequestration potential differs among soils depending on climate, soil properties and management, with the highest potential for poor soils (SOC stock farthest from saturation).</p><p>Modelling can be used to estimate the technical potential to sequester C of agricultural land under different mitigation practices for the next decades under different climate scenarios. The ECOSSE model was developed to simulate soil C dynamics and GHG emissions in mineral and organic soils. A spatial version of the model (GlobalECOSSE) was adapted to simulate agricultural soils around the world to calculate the SOC change under changing management and climate.</p><p>Practices like different tillage management, crop rotations and residue incorporation showed regional differences and the importance of adapting mitigation practices under an increased changing climate. A fast adoption of practices that increase SOC has its own challenges, as the potential to sequester C is high until the soil reached a new C equilibrium. Therefore, the potential to use soil C sequestration to reduce overall GHG emissions is limited. The results showed a high potential to sequester C until 2050 but much lower rates in the second half of the century, highlighting the importance of using soil C sequestration in the coming decades to reach net zero by 2050.</p>


2005 ◽  
Vol 31 ◽  
pp. 279-309 ◽  
Author(s):  
Axel Gosseries

Evidence provided by the scientific community strongly suggests that limits should be placed on greenhouse gas (GHG) emissions. This means that states, firms, and individuals will have to face potentially serious burdens if they are to implement these limits. Which principles of justice should guide a global regime aimed at reducing greenhouse gas (GHG) emissions originating from human activities, and most notably from CO2 emissions? This is both a crucial and difficult question. Admittedly, perhaps this question is too ambitious, given the uncertainties and complexities characterizing the issue of climate change. Yet, rather than listing them all at this stage, let us address the question in a straightforward manner, introducing some of these complexities as the need arises.


Author(s):  
Farshid Zabihian ◽  
Alan S. Fung

Nowadays, the global climate change has been a worldwide concern and the greenhouse gases (GHG) emissions are considered as the primary cause of that. The United Nations Conference on Environment and Development (UNCED) divided countries into two groups: Annex I Parties and Non-Annex I Parties. Since Iran and all other countries in the Middle East are among Non-Annex I Parties, they are not required to submit annual GHG inventory report. However, the global climate change is a worldwide phenomenon so Middle Eastern countries should be involved and it is necessary to prepare such a report at least unofficially. In this paper the terminology and the methods to calculate GHG emissions will first be explained and then GHG emissions estimates for the Iranian power plants will be presented. Finally the results will be compared with GHG emissions from the Canadian electricity generation sector. The results for the Iranian power plants show that in 2005 greenhouse gas intensity for steam power plants, gas turbines and combined cycle power plants were 617, 773, and 462 g CO2eq/kWh, respectively with the overall intensity of 610 g CO2eq/kWh for all thermal power plants. This GHG intensity is directly depend on efficiency of power plants. Whereas, in 2004 GHG intensity for electricity generation sector in Canada for different fuels were as follows: Coal 1010, refined petroleum products 640, and natural gas 523 g CO2eq/kWh, which are comparable with same data for Iran. For average GHG intensity in the whole electricity generation sector the difference is much higher: Canada 222 vs. Iran 610g CO2eq/kWh. The reason is that in Canada a considerable portion of electricity is generated by hydro-electric and nuclear power plants in which they do not emit significant amount of GHG emissions. The average GHG intensity in electricity generation sector in Iran between 1995 and 2005 experienced 13% reduction. While in Canada at the same period of time there was 21% increase. However, the results demonstrate that still there are great potentials for GHG emissions reduction in Iran’s electricity generation sector.


2021 ◽  
Vol 47 (2) ◽  
pp. 332-348
Author(s):  
Tariq Umar

Reduction in emissions is the key to tackle climate change issues and achieve environmental sustainability. The Gulf Cooperation Council member countries however, not only generate the highest quantity of MSW/capita when compared globally but also in most of these countries such waste is just dumped at different landfill stations. In Oman, the total quantity of MSW stood at 2.0 million tonnes/year. The emission from this waste is estimated at 2,989,467 tonnes/year (CO2 Equivalent). This article attempts to develop frameworks that considered landfilling, composting, and recycling of MSW and compared the emissions of these frameworks. The framework (F2) which proposes the landfilling and composting process for the organic waste which normally goes to landfills results in an increase of emissions by 7% as compared to landfill practice. Similarly, the samples of MSW collected in Oman show a good amount of recycling waste. The framework (F3) which considers the landfill, composting, and recycling reduced the total Greenhouse Gas emissions from 2,989,467 tonnes/year to 2,959,735 tonnes/year (CO2 Equivalent); representing a total reduction of 1% in emissions. Although composting increases the emissions, however, considering composting and recycling will not only reduce the burden on landfills but will promote agricultural and industrial activates.


2021 ◽  
Author(s):  
Carl-Fredrik Johannesson ◽  
Klaus Steenberg Larsen ◽  
Brunon Malicki ◽  
Jenni Nordén

<p>Boreal forests are among the most carbon (C) rich forest types in the world and store up to 80% of its total C in the soil. Forest soil C development under climate change has received increased scientific attention yet large uncertainties remain, not least in terms of magnitude and direction of soil C responses. As with climate change, large uncertainties remain in terms of the effects of forest management on soil C sequestration and storage. Nonetheless, it is clear that forest management measures can have far reaching effects on ecosystem functioning and soil conditions. For example, clear cutting is a widely undertaken felling method in Scandinavia which profoundly affects the forest ecosystem and its functioning, including the soil. Nitrogen (N) fertilization is another common practice in Scandinavia which, despite uncertainties regarding effects on soil C dynamics, is being promoted as a climate change mitigation tool. A more novel practice of biochar addition to soils has been shown to have positive effects on soil conditions, including soil C storage, but studies on biochar in the context of forests are few.</p><p>In the face of climate change, the ForBioFunCtioN project is dedicated to investigating the response of boreal forest soil CO<sub>2</sub> and CH<sub>4</sub> fluxes to experimentally increased temperatures and increased precipitation – climatic changes in line with projections over Norway – within a forest management context. The experiment is set in a Norwegian spruce-dominated bilberry chronosequence, including a clear-cut site, a middle-aged thinned stand, a mature stand and an old unmanaged stand. Warming, simulated increased precipitation, N fertilizer and biochar additions will be applied on experimental plots in an additive manner that allows for disentangling the effects of individual parameters from interaction effects. Flux measurements will be undertaken at high temporal resolution using the state-of-the-art LI-7810 Trace Gas Analyzer (©LI-COR Biosciences). The presentation will show the experimental setup and first measurements from the large-scale experiment.</p>


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Lefebvre ◽  
Adrian Williams ◽  
Jeroen Meersmans ◽  
Guy J. D. Kirk ◽  
Saran Sohi ◽  
...  

Abstract Sugarcane (Saccharum officinarum L.) cultivation leaves behind around 20 t ha−1 of biomass residue after harvest and processing. We investigated the potential for sequestering carbon (C) in soil with these residues by partially converting them into biochar (recalcitrant carbon-rich material). First, we modified the RothC model to allow changes in soil C arising from additions of sugarcane-derived biochar. Second, we evaluated the modified model against published field data, and found satisfactory agreement between observed and predicted soil C accumulation. Third, we used the model to explore the potential for soil C sequestration with sugarcane biochar in São Paulo State, Brazil. The results show a potential increase in soil C stocks by 2.35 ± 0.4 t C ha−1 year−1 in sugarcane fields across the State at application rates of 4.2 t biochar ha−1 year−1. Scaling to the total sugarcane area of the State, this would be 50 Mt of CO2 equivalent year−1, which is 31% of the CO2 equivalent emissions attributed to the State in 2016. Future research should (a) further validate the model with field experiments; (b) make a full life cycle assessment of the potential for greenhouse gas mitigation, including additional effects of biochar applications on greenhouse gas balances.


Sign in / Sign up

Export Citation Format

Share Document