| 1. |
- Ahlgren, Serina, et al.
(författare)
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Climate and biodiversity impact of beef and lamb production – A case study in Sweden
- 2024
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Ingår i: Agricultural Systems. - 1873-2267 .- 0308-521X. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: The climate impact of meat production is a hotly debated topic. What is less often highlighted is that grazing ruminants can have positive impacts on biodiversity. OBJECTIVE: The aim of this study was to use a life cycle perspective to assess both the climate and biodiversity impact of different beef and lamb production systems in Sweden. METHODS: Applying a life cycle perspective, a quantitative method to assess biodiversity was used, with a scoring system based on land use. For the climate impact calculations, the ClimAg biophysical systems model was used, including emissions from drained organic soils and carbon sequestration in mineral soils. The functional unit was 1 kg carcass weight. RESULTS AND CONCLUSIONS: The results indicated large differences in biodiversity and climate impact between the production systems studied. Dairy bulls had relative low emissions of greenhouse gases, but also a low biodiversity score (a high score indicates higher level of biodiversity). Beef breed steers and heifers had higher emissions of greenhouse gases but a higher biodiversity score, suggesting a trade-off between climate and biodiversity impact. Also for lamb meat, greenhouse gas emissions vary among production systems. A system with winter born lambs slaughtered in spring, closely followed by spring born lambs slaughtered in autumn, had the lowest emissions, while spring born lambs slaughtered in winter had the highest emissions. Winter lambs on the other hand, had a relatively high biodiversity score, due to a long rearing period and an extensive land use with a high proportion of semi-natural grasslands. Climate impact was in all systems related to methane from enteric fermentation, emissions from manure storage, and emissions from organic soils. With the assumptions made in this study, soil carbon sequestration is suggested to reduce the climate impact by 5–7% of the total emissions. Biodiversity impact was in all systems positively related to the amount of grazing in permanent grasslands, in particular semi-natural grasslands. Because semi-natural grasslands are among the most species rich terrestrial ecosystems in Europe, a large surface area grazed resulted in high biodiversity scores in the present model. SIGNIFICANCE: This study used a novel approach for biodiversity assessment, where the positive contribution of semi-natural grasslands to biodiversity was quantified and put in relation to the modelled climate impact.
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| 2. |
- Ahlgren, Serina, et al.
(författare)
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Tractive power in organic farming based on fuel cell technology : Energy balance and environmental load
- 2009
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 102:1-3, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- This study analysed a future hypothetical organic farm self-sufficient in renewable tractor fuel. Biomass from the farm was assumed to be transported to a central fuel production plant and the fuel returned to the farm, where it was utilised in fuel cell powered tractors. The land use, energy balance and environmental impact of five different scenarios were studied. In the first two scenarios, straw was used as raw material for production of hydrogen or methanol via thermochemical gasification. In the third and fourth scenarios, short rotation forest (Salix) was used as raw material for the same fuels. In the fifth scenario, ley was used as raw material for hydrogen fuel via biogas production. The straw scenarios had the lowest impact in all studied environmental impact categories since the Salix scenarios had higher soil emissions and the ley scenario had comparatively large emissions from the fuel production. The energy balance was also favourable for straw, 16.3 and 19.5 for hydrogen and methanol respectively, compared to Salix 14.2 and 15.6. For ley to hydrogen the energy balance was only 6.1 due to low efficiency in the fuel production. In the Salix scenarios, 1.6% and 2.0% of the land was set aside for raw material production in the hydrogen and methanol scenarios respectively. In the straw scenarios no land needed to be reserved, but straw was collected on 4.3% and 5.3% of the area for hydrogen and methanol respectively. To produce hydrogen from ley, 4% of the land was harvested. The study showed that the difference in environmental performance lay in choice of raw material rather than choice of fuel. Hydrogen is a gas with low volumetric energy density, which requires an adapted infrastructure and tractors equipped with gas tanks. This leads to the conclusion that methanol probably will be the preferred choice if a fuel cell powered farm would be put into practice in the future. © 2009 Elsevier Ltd. All rights reserved.
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| 3. |
- Angeler, David
(författare)
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Resilience theory and coerced resilience in agriculture
- 2023
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 206
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Tidskriftsartikel (refereegranskat)abstract
- There is uncertainty regarding the resilience of modern intensive agricultural systems, given that they have been developed recently in history (post-WWII). Historically, agricultural sciences have focused on scales from the molecular and plant to plot and field. Innovation in this space has led to increased efficiency in agricultural production at local scales, but it remains a challenge to scale up such knowledge to explain dynamics in soil, water, nutrients, and biodiversity at larger spatial and temporal scales, or to account for complex interactions and feedbacks. We present agricultural systems as coerced regimes, and then discuss three underutilized resil-ience concepts relevant for investigations of agricultural systems as multi-scaled complex adaptive systems (CASs): scales, uncertainty, and regime shifts. Framing agricultural systems as coerced regimes situates them according to their degree of self-organization, the impact on resilience, and the possibility of alternative regimes. Collectively, these resilience concepts offer a path forward for evaluating the resilience of modern agriculture systems and expanding agroecological principles to scales beyond that of the field or farm because they explicitly account for agricultural systems as multi-scaled complex adaptive systems. This knowledge base has immediate management implications from the farm to continental scale, as climate and land use change force challenging decisions regarding the ability of modern agriculture to persist as is, adapt, or transform in order to avoid un-desirable regime shifts.
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| 4. |
- Barrios Latorre, Sergio Alejandro, et al.
(författare)
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Exploring the benefits of intermediate crops : Is it possible to offset soil organic carbon losses caused by crop residue removal?
- 2024
-
Ingår i: Agricultural Systems. - 0308-521X .- 1873-2267. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Agriculture plays a central role as a feedstock provider for the bioeconomy. However, utilization competing with food production and associated land use change have previously been a matter of debate. Nonetheless, strengthening the productivity of agroecosystems through sustainable intensification can prevent the depletion of natural resources, enhance food security, and facilitate adaptation to and mitigation of climate change. OBJECTIVE: This study explores the effects of combining crop residue removal for use as biomass feedstock with the establishment of intermediate crops to compensate for organic carbon depletion in arable land in Sweden. METHODS: The analysis relied on Swedish national agricultural statistics at the highest available spatial resolution (yield survey district). Crop residue calculations factored in crop:residue ratios, and harvestable and recoverable potentials. A model was devised to estimate land availability for cultivating intermediate crops based on generalized crop rotation sequences, and a spatial interpolation was employed to determine oilseed radish yields as a model intermediate crop. Estimates of long-term soil carbon inputs hinged on biomass carbon content and humification coefficients dependent on soil clay content. RESULTS AND CONCLUSION: The total annual residual biomass availability in the country stands at approximately 2139 kt per year. The potential harvestable biomass production from intermediate crops was estimated at 383 kt per year. However, spatial differences were evident in total biomass production and effects on soil organic carbon inputs. For the majority of districts, the inclusion of intermediate crops could offset the negative effect of a complete removal of crop residues on soil organic carbon inputs. In other cases, establishing intermediate crops could not compensate for these negative effects, but some differences were observed when comparing the harvesting and the incorporation of the intermediate crops' biomass. Spatial disparities originated from variations in soil texture, intermediate crop yield, and rotation sequences. SIGNIFICANCE: This research is an attempt to address the challenge of maintaining and increasing the soil carbon stocks under the context of a growing biomass demand in a developing biobased economy. It highlights the divergent effects of combining crop residue removal with the inclusion of intermediate crops under distinct agroecological conditions in the Northern European context. By giving estimates on biomass availability and effects on soil organic carbon inputs, we provide information that can support decision making for bioeconomy planning and sustainable resource utilization. This also has long-term implications for preservation of soil fertility, agricultural productivity and climate change mitigation.
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| 5. |
- Barron, Jennie
(författare)
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Impact of best management practices on sustainable crop production and climate resilience in smallholder farming systems of South Asia
- 2021
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 194
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Forskningsöversikt (refereegranskat)abstract
- CONTEXT: A host of best water and soil management practices (BMPs) hold promise in addressing water scarcity and land degradation to enable sustainable crop intensification in smallholder farming systems.OBJECTIVE This study quantifies the effect of BMPs on crop productivity, income, water saving and water balance components and identifies gaps for future research.METHODS: This paper synthesizes the performance of BMPs and the existing data gap by reviewing 108 published studies from the Indian subcontinent which capture a diverse range of rainfall and cropping systems.RESULTS AND CONCLUSIONS: In situ conservation measures helped enhance crop yields by 200-1000 kg/ha, reduced cost of cultivation and enhanced incomes by US$ 10-200/ha/year. The BMPs were helpful in enabling annual water saving in the range of 50 mm to 300 mm by either conserving residual soil moisture or saving irrigation water resulting in enhanced water productivity. Interventions such as direct seeded rice and laser land leveling were found most effective in terms of water saving and in reducing cost of cultivation. On the other hand, ex situ rainwater harvesting interventions helped enhance groundwater recharge by harvesting an additional 50-150 mm of surface runoff which helped increase crop yields, led to sustainable crop intensification and strengthened the number of ecosystem services. Most of the published literature on in situ conservation measures are studies that were carried out at research stations, which show promise of sustainable intensification. However, greater efforts are needed to document learnings from farmer/community scale interventions for effective scaling up. There is also a gap in data availability that hampers a clear understanding of the impact of ex situ rainwater harvesting interventions and ecosystem trade-offs; moreover the data available covers short pe- riods and only covers an area of up to 10 km(2). We recommend the monitoring of long-term system-level impact indicators to realize the potential of ex situ rainwater harvesting interventions in a systems perspective and better grasp the ecosystem trade-offs.SIGNIFICANCE: More importantly, the review revealed the ample scope of integrating in situ and ex situ in- terventions to build system-level resilience in smallholder farming systems in order to accelerate progress to- wards achieving the United Nations Sustainable Development Goals (SDGs).
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| 6. |
- Barron, Jennie, et al.
(författare)
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Risk analysis and economic viability of water harvesting for supplemental irrigation in the Semi-arids
- 2005
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 83:3, s. 231-250
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Tidskriftsartikel (refereegranskat)abstract
- Food insecurity affects a large portion of the population in sub-Saharan Africa (SSA). To meet future food requirements current rainfed farming systems need to upgrade yield output. One way is to improve water and fertiliser management in crop production. But adaptation among farmers will depend on perceived risk reduction of harvest failure as well as economic benefit for the household. Here, we present risk analysis and economical benefit estimates of a water harvesting (WH) system for supplemental irrigation (SI). Focus of the analysis is on reducing investment risk to improve self-sufficiency in staple food production. The analysis is based on data from two on-farm experimental sites with SI for cereals in currently practised smallholder farming system in semi-arid Burkina Faso and Kenya, respectively. The WH system enables for both SI of staple crop (sorghum and maize) and a fully irrigated off-season cash crop (tomatoes). Different investment scenarios are presented in a matrix of four reservoir sealants combined with three labour opportunity costs. It is shown that the WH system is labour intensive but risk-reducing investment at the two locations. The current cultivation practices do not attain food self-sufficiency in farm households. WH with SI resulted in a net profit of 151–626 USD year−1 ha−1 for the Burkina case and 109–477 USD year−1 ha−1 for the Kenya case depending on labour opportunity cost, compared to −83 to 15 USD year−1 ha−1 for the Burkina case and 40–130 USD year−1 ha−1 for the Kenyan case for current farming practices. Opportunity cost represents 0–66% of the investment cost in an SI system depending on type of sealant. The most economical strategy under local labour conditions was obtained using thin plastic sheeting as reservoir sealant. This resulted in a net profit of 390 and 73 USD year−1 ha−1 for the Burkina Faso and Kenyan respective site after household consumption was deducted. The analysis suggests a strong mutual dependence between investment in WH for SI and input of fertiliser. The WH system is only economically viable if combined with improved soil fertility management, but the investment in fertiliser inputs may only be viable in the long term when combined with SI.
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| 7. |
- Bernes, Gun, et al.
(författare)
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Positive deviant strategies implemented by organic multi-species livestock farms in Europe
- 2022
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 201
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Transitions to more sustainable livestock production systems are increasingly demanded by parts of society. Scientists suggest moving towards diversified farming systems due to their potential environmental and economic benefits, especially in the organic sector. However, empirical knowledge of multi-species livestock farms, i.e. farms keeping two or more animal species, is lacking.OBJECTIVE: Our objectives were to identify European organic multi-species livestock farms that outperform their peers despite having the same resources and constraints, and characterize their distinctive management principles.METHODS: We conducted surveys on 102 farms in seven European countries: Austria, Belgium, France, Ger-many, Italy, Sweden and Switzerland. We restricted the analysis to a sub-sample of 75 farms that had complete data and that covered 3 main livestock combinations (cattle and sheep, cattle and pigs, cattle and poultry) with similar number of farms. We implemented a positive deviant approach based on three indicators: land pro-ductivity, nitrogen input dependence and satisfaction regarding income.RESULTS AND CONCLUSIONS: Five structurally diverse positive deviant farms were identified with 4 types of livestock combinations represented, and farmland area ranging from 25 to 273 ha, herd size from 33 to 146 livestock units (LU) and total workforce size from 1 to 24 annual worker units (AWU). These farms were located on a trade-off between land productivity and autonomy for feed, and all but one had high overall autonomy for feed (89-100% against a mean of 76% for the whole sample). Their diversity of pastures, crops and livestock species and their diversification beyond agricultural production were controlled (e.g. no agritourism) and below that of the other sample farms, to remain manageable by the farmers while still allowing to buffer shocks and hazards. Interactions among farm enterprises remained limited to matter (mainly grain, straw, hay, manure) flows, and practices requiring specific efforts and investments (e.g. for fencing), such as co-grazing of different livestock and crop residues grazing, were avoided.SIGNIFICANCE: We conducted the first integrated study on European organic multi-species livestock farms and identified key management principles implemented on positive deviant farms. We showed that whatever their size, farms outperforming their peers do not necessarily maximize diversity of agricultural productions and of non-agricultural activities, and interactions among farm enterprises but that they remain at a level of complexity manageable by the farmers. These principles will inform farmers running multi-species livestock farms or transitioning to this model.
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| 8. |
- Blanco Penedo, Isabel, et al.
(författare)
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Structural characteristics of organic dairy farms in four European countries and their association with the implementation of animal health plans
- 2019
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 173, s. 244-253
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to classify the diversity of organic dairy farms in four European countries according to their structural characteristics and investigate the association of these farm types with implementation of herd health plans. A Multiple Correspondence Analysis (MCA), followed by Agglomerative Hierarchical Clustering (AHC), was used to classify the farms. Data for the analysis came from a survey of 192 organic farms from France, Germany, Spain and Sweden and contained farm and farmer descriptions from which the typologies were derived. Herd health plans was agreed for each farm, via a participatory approach involving the farmers, their veterinarians and other advisors (e.g. dairy advisors) by the use of an impact matrix. The MCA yielded two principal component axes explaining 51.3% of variance. Three farm groups were identified by ARC using the factor scores derived from the MCA. Cluster 1, the most numerous group (56.7% of the sample), had medium herd sizes with moderate use of pasture and moderate intensity of input use. Cluster 2, representing 17.7% of the sample, were the most extensive system and mainly of very small farm size. Cluster 3 (25.5% of the sample and only found in Sweden), had an intensive management approach, but relatively low stocking rate. The analysis also showed that organic dairy farms adopted differentiated strategies towards economic assets and animal health status, according to group membership. The typology therefore provides insights into the potential for advisory strategies relating to husbandry practices, different housing, pasture management and intensity, etc. adapted to different groups of farms. Regarding herd health plan implementation, Cluster 1 was the group with most implemented actions and Cluster 2 with lowest rate of implemented actions. These results may be used as background for directing (tailored) advice strategies, i.e. different types of organic dairy farms (clusters) may require different types of advisory services and recommendations adapted to the specific farm situation in order to deliver future improvements in animal health.
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| 9. |
- Bodin, P., et al.
(författare)
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Accounting for interannual variability in agricultural intensification : The potential of crop selection in Sub-Saharan Africa
- 2016
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 148, s. 159-168
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Tidskriftsartikel (refereegranskat)abstract
- Providing sufficient food for a growing global population is one of the fundamental global challenges today. Crop production needs not only to be increased, but also remain stable over the years, in order to limit the vulnerability of producers and consumers to inter-annual weather variability, especially in areas of the world where the food consumed is mainly produced locally (e.g. Sub Saharan Africa (SSA)). For subsistence agriculture, stable yields form a crucial contribution to food security. At a regional to global scale dynamical crop models can be used to study the impact of future changes in climate on food production. However, simulations of future crop production, for instance in response to climate change, often do not take into account either changes in the sown areas of crops or yield interannual variability. Here, we explore the response of simulated crop production to assumptions of crop selection, also taking into account interannual variability in yields and considering the response of agricultural productivity to climate change. We apply the dynamic global vegetation model LPJ-GUESS, which is designed to simulate yield over large regions under a changing environment. Model output provides the basis for selecting the relative fractions of sown areas of a range of crops, either by selecting the highest yielding crop, or by using an optimization approach in which crop production is maximized while the standard deviation in crop production is kept at below current levels. Maximizing simulated crop production for current climate while keeping interannual variability in crop production constant at today's level generates rather similar simulated geographical distributions of crops compared to observations. Even so, the optimization results suggest that it is possible to increase crop production regionally by adjusting crop selection, both for current and future climate, assuming the same cropland cover as today. For future climates modelled production increase is > 25% in more than 15% of the grid cells. For a small number of grid cells it is possible to both increase crop production while at the same time decreasing its interannual variability. Selecting the highest yielding crop for any location will lead to a large potential increase in mean food production, but at the cost of a very large increase in variability.
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| 10. |
- Boke Olén, Niklas, et al.
(författare)
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Effects of farm type on food production, landscape openness, grassland biodiversity, and greenhouse gas emissions in mixed agricultural-forestry regions
- 2021
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 189
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Tidskriftsartikel (refereegranskat)abstract
- Context: The global demand for food is expected to continue increasing for decades, which may drive both agricultural expansion and intensification. The associated environmental impacts are potentially considerable but will depend on how the agricultural sector develops. Currently, there are contrasting regional developments in agriculture; expansion and/or intensification in some regions and abandonment in others, as well as changes in the type of farming. However, the environmental consequences of changes in farm type are not well understood. Objective: We have evaluated the impacts of farm type on food production and three key environmental variables—landscape openness, grassland biodiversity and greenhouse gas (GHG) emissions—in three marginal agricultural regions in Sweden. Methods: We do this by first dividing the population of farms in each region into types, based on their land-use and livestock holdings using an innovative clustering method. Thereafter we analysed changes in production activities for farm types over time and evaluated the environmental and food-production impacts, where landscape openness is quantified using a novel indicator. Results and conclusion: Our results show that there is not one single farm type that would simultaneously maximize food production, grassland biodiversity, and landscape openness, whilst minimizing GHG emissions. However, there exists considerable potential to manage the trade-offs between food production and these environmental variables. For example, by reducing land use for dairying and instead increasing both cropping for food production and extensive livestock grazing to maintain landscape openness and biodiversity-rich semi-natural pastures, it would keep food production at similar levels. Significance: Our farm typology allows us to assess the multifunctionality of farming, by relating contrasting production activities to multiple ecosystem services, grassland biodiversity and GHG emissions for informing policy towards more sustainable agriculture. We have demonstrated this with examples under Swedish conditions, but it should to a large extent also be applicable for other countries.
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| 11. |
- Bolinder, Martin, et al.
(författare)
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Canadian farm-level soil carbon change assessment by merging the greenhouse gas model Holos with the Introductory Carbon Balance Model (ICBM)
- 2016
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 143, s. 76-85
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Tidskriftsartikel (refereegranskat)abstract
- The farm-level model Holos, developed to explore mitigation options for greenhouse gas emissions (GHG) from Canadian farming systems, includes soil carbon change as a prominent component. Soil carbon was assumed to be constant, except where there was recent change in land use or management (e.g., conventional vs. reduced vs. no tillage). The factors associated with the changes were derived using CENTURY model simulations. To make Holos more responsive to farm management (e.g., crop rotation and residue management) and inter-annual climate variation, it was decided to replace the carbon change factors with the Introductory Carbon Balance Model (ICBM), a simple two carbon pool model driven by inputs from above- and belowground crop residues and manure. We showcase how the model will simulate the impact of crop rotation management decisions on soil carbon change, focussing on the choice of crop and crop residue retention, but considering also tillage and fertilization management. We argue that simulating carbon change at each field involved in the rotation is advantageous because it allowsto test the rotation resilience with respect to inter-annual climate variation as well as to validate the model outputs using measurements of scientific long-term field experiments. We propose to report the farm-level carbon change results ranging from annual to centennial time frames which would be in line with the reporting requirements in carbon credit programs, while giving the user the capability to project and test new crop rotation systems using long-term carbon change forecasts. Crown Copyright (C) 2015 Published by Elsevier Ltd. All rights reserved.
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| 12. |
- Cong, Ronggang, et al.
(författare)
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Managing soil natural capital: An effective strategy for mitigating future agricultural risks?
- 2014
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 129, s. 30-39
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Tidskriftsartikel (refereegranskat)abstract
- Uncontrollable events such as adverse weather and volatile prices present considerable risks for arable farmers. Soil natural capital, which views the capacity of soil biodiversity to generate ecosystem services as a component of farm capital, could be important for the stability and resilience of arable production systems. We investigate therefore whether managing soil natural capital could be an effective strategy for mitigating future agricultural risks. We do this by constructing a dynamic stochastic portfolio model to optimize the stock of soil organic carbon (SOC)—our indicator of soil natural capital—when considering both the risks and returns from farming. SOC is controlled via the spatial and temporal allocation of cash crops and an illustrative replenishing land use. We find that higher soil natural capital buffers yield variance against adverse weather and reduces reliance on external inputs. Managing soil natural capital has therefore the potential to mitigate two serious agricultural risks: energy price shocks and adverse weather events, both of which are likely to be exacerbated in the future due to, e.g., globalization and climate change.
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| 13. |
- Daum, Thomas, 1990, et al.
(författare)
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Connected cows and cyber chickens? Stocktaking and case studies of digital livestock tools in Kenya and India
- 2022
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 196
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: There are high hopes that digital tools can reduce constraints to livestock development, which in turn promises to alleviate poverty, improve food and nutrition security, and reduce environmental footprints. Yet, little systematic evidence exists on the state of digital livestock in low- and middle-income-countries. Thus, it remains unclear whether such high hopes are justified. OBJECTIVE: Focusing on India and Kenya, we aim to better understand, among others, the degree of technological sophistication of the digital tools used, the types of value chains and constraints addressed, the types of business models pursued, and more broadly the opportunities and challenges of digital tools for agricultural development. METHOD: We combine a review of digital tools in India and Kenya with three “on-the-ground” case studies: Herdman, a tool for Indian dairy organizations working with small-scale livestock keepers, facilitating data collection and supervision of field agents; Farmtree, a tool supporting medium-scale livestock keepers in India to manage their herds, and iCow, an e-extension tool for farmers in Kenya. For the review, we develop a conceptual framework that distinguishes different types of tools: 1) “simple digital tools”, providing generic information, 2) “smart digital tools”, providing tailored information based on data entered by livestock keepers, 3) “smart digital tools”, using data from sensors, 4) “digital tools for value chains”, enabling the integration of value chain actors, 5) “automated digital systems”, which are coupled with robots, allowing for automation. RESULTS AND CONCLUSIONS: Digital tools provide many new options to address constraints to livestock development. So far, most tools are “simple digital tools”, followed by “smart digital tools” using manual data and tools for value chains. Such tools that only require smartphone ownership are the “sweet spot” for supporting digital livestock development; however, even embodied “smart digital tools” using sensors can be of relevance for small-scale livestock keepers with appropriate organizational models. Most digital tools focus on dairy production, suggesting neglect of other types of livestock, and there are few tools for pastoralists. SIGNIFICANCE: The conceptual framework as well as many of the lessons learned are of relevance to understanding the contribution of digital tools to livestock development - and agricultural development more broadly - in low- and middle-income-countries. While digital tools are no silver bullets – and come with some new challenges such as data security and sovereignty concerns - they are likely to become a key pillar of agricultural and livestock development in the near future.
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| 14. |
- Emanuelson, Ulf, et al.
(författare)
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Capturing systemic interrelationships by an impact analysis to help reduce production diseases in dairy farms.
- 2017
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 153, s. 43-52
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Tidskriftsartikel (refereegranskat)abstract
- Production diseases, such as metabolic and reproductive disorders, mastitis, and lameness, emerge from complex interactions between numerous factors (or variables) but can be controlled by the right management decisions. Since animal husbandry systems in practice are very diverse, it is difficult to identify the most influential components in the individual farm context. However, it is necessary to do this to control disease, since farmers are severely limited in their access to resources, and need to invest in management measures most likely to have an effect. In this study, systemic impact analyses were conducted on 192 organic dairy farms in France, Germany, Spain, and Sweden in the context of reducing the prevalence of production diseases. The impact analyses were designed to evaluate the interrelationships between farm variables and determine the systemic roles of these variables. In particular, the aim was to identify the most influential variables on each farm. The impact analysis consisted of a stepwise process: (i) in a participatory process 13 relevant system variables affecting the emergence of production diseases on organic dairy farms were defined; (ii) the interrelationships between these variables were evaluated by means of an impact matrix on the farm-level, involving the perspectives of the farmer, an advisor and the farm veterinarian; and (iii) the results were then used to identify general system behaviour and to classify variables by their level of influence on other system variables and their susceptibility to influence. Variables were either active (high influence, low susceptibility), reactive (low influence, high susceptibility), critical (both high), or buffering (both low). An overall active tendency was found for feeding regime, housing conditions, herd health monitoring, and knowledge and skills, while milk performance and financial resources tended to be reactive. Production diseases and labour capacity had a tendency for being critical while reproduction management, dry cow management, calf and heifer management, hygiene and treatment tended to have a buffering capacity. While generalised tendencies for variables emerged, the specific role of variables could vary widely between farms. The strength of this participatory impact assessment approach is its ability, through filling in the matrix and discussion of the output between farmer, advisor and veterinarian, to explicitly identify deviations from general expectations, thereby supporting a farm-specific selection of health management strategies and measures. (C) 2017 Elsevier Ltd. All rights reserved.
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| 15. |
- Flysjö, A., et al.
(författare)
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The impact of various parameters on the carbon footprint of milk production in New Zealand and Sweden
- 2011
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Ingår i: Agricultural Systems. - : Elsevier BV. - 1873-2267 .- 0308-521X. ; 104:6, s. 459-469
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Tidskriftsartikel (refereegranskat)abstract
- The carbon footprint (CF) of milk production was analysed at the farm gate for two contrasting production systems; an outdoor pasture grazing system in New Zealand (NZ) and a mainly indoor housing system with pronounced use of concentrate feed in Sweden (SE). The method used is based on the conceptual framework of lifecycle assessment (LCA), but only for greenhouse gas (GHG) emissions. National average data were used to model the dairy system in each country. Collection of inventory data and calculations of emissions were harmonised to the greatest extent possible for the two systems. The calculated CF for 1kg of energy corrected milk (ECM), including related by-products (surplus calves and culled cows), was 1.00kg carbon dioxide equivalents (CO2e) for NZ and 1.16kg CO2e for SE. Methane from enteric fermentation and nitrous oxide emissions from application of nitrogen (as fertiliser and as excreta dropped directly on the field) were the main contributors to the CF in both countries. The most important parameters to consider when calculating the GHG emissions were dry matter intake (DMI), emission factor (EF) for methane from enteric fermentation, amount of nitrogen applied and EF for direct nitrous oxide emissions from soils. By changing one parameter at a time within 'reasonable' limits (i.e. no extreme values assumed), the impact on the total CF was assessed and showed changes of up to 15%. In addition, the uncertainty in CF estimates due to uncertainty in EF for methane from enteric fermentation and nitrous oxide emissions (from soil and due to ammonia volatilisation) were analysed through Monte Carlo simulation. This resulted in an uncertainty distribution corresponding to 0.60-1.52kg CO2e kg-1 ECM for NZ and 0.83-1.56kg CO2e kg-1 ECM for SE (in the prediction interval 2.5-97.5%). Hence, the variation within the systems based on the main EF is relatively large compared with the difference in CF between the countries. © 2011 Elsevier Ltd.
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| 16. |
- Fredriksson, H., et al.
(författare)
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Use of on-farm produced biofuels on organic farms : Evaluation of energy balances and environmental loads for three possible fuels
- 2006
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 89:1, s. 184-203
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to evaluate systems making organic farms self-sufficient in farm-produced bio-based fuels. The energy balance and environmental load for systems based on rape methyl ester (RME), ethanol and biogas were evaluated using a life cycle perspective. Complete LCAs were not performed. Important constraints when implementing the systems in practice were also identified. The RME scenario showed favourable energy balance and produced valuable by-products but was less positive in some other aspects. The use of land was high and thereby also the emissions associated with cultivation. Emissions, with the exception of CO2, during utilisation of the fuel were high compared to those of the other fuels in the study. The technology for production and use of RME is well known and easy to implement at farm scale. The production of ethanol was energy consuming and the by-products were relatively low value. However, the area needed for cultivation of raw material was low compared to the RME scenario. The production and utilisation of ignition improver and denaturants were associated with considerable emissions. Suitable ethanol production technology is available but is more optimal for large scale systems. The biogas scenario had a low relative need for arable land, which also resulted in smaller soil emissions to air and water. Another advantage was the potential to recycle plant nutrients. On the other hand, the potential emissions of methane from storage of digestate, upgrading of biogas and methane losses during utilisation of fuel produced a negative impact, mainly on global warming. Small scale technology for biogas cleaning and storage is not fully developed and extensive tractor modifications are necessary. The global warming effects of all three systems studied were reduced by 58-72% in comparison to a similar farming system based on diesel fuel. However, the fuel costs were higher for all scenarios studied compared to current diesel prices. In particular, the large costs for seasonal storage of gas meant that the biogas scenario described is currently not financially viable. © 2005 Elsevier Ltd. All rights reserved.
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| 17. |
- Fronzek, Stefan, et al.
(författare)
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Classifying multi-model wheat yield impact response surfaces showing sensitivity to temperature and precipitation change
- 2018
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 159, s. 209-224
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Tidskriftsartikel (refereegranskat)abstract
- Crop growth simulation models can differ greatly in their treatment of key processes and hence in their response to environmental conditions. Here, we used an ensemble of 26 process-based wheat models applied at sites across a European transect to compare their sensitivity to changes in temperature (-2 to +9°C) and precipitation (-50 to +50%). Model results were analysed by plotting them as impact response surfaces (IRSs), classifying the IRS patterns of individual model simulations, describing these classes and analysing factors that may explain the major differences in model responses.The model ensemble was used to simulate yields of winter and spring wheat at four sites in Finland, Germany and Spain. Results were plotted as IRSs that show changes in yields relative to the baseline with respect to temperature and precipitation. IRSs of 30-year means and selected extreme years were classified using two approaches describing their pattern.The expert diagnostic approach (EDA) combines two aspects of IRS patterns: location of the maximum yield (nine classes) and strength of the yield response with respect to climate (four classes), resulting in a total of 36 combined classes defined using criteria pre-specified by experts. The statistical diagnostic approach (SDA) groups IRSs by comparing their pattern and magnitude, without attempting to interpret these features. It applies a hierarchical clustering method, grouping response patterns using a distance metric that combines the spatial correlation and Euclidian distance between IRS pairs. The two approaches were used to investigate whether different patterns of yield response could be related to different properties of the crop models, specifically their genealogy, calibration and process description.Although no single model property across a large model ensemble was found to explain the integrated yield response to temperature and precipitation perturbations, the application of the EDA and SDA approaches revealed their capability to distinguish: (i) stronger yield responses to precipitation for winter wheat than spring wheat; (ii) differing strengths of response to climate changes for years with anomalous weather conditions compared to period-average conditions; (iii) the influence of site conditions on yield patterns; (iv) similarities in IRS patterns among models with related genealogy; (v) similarities in IRS patterns for models with simpler process descriptions of root growth and water uptake compared to those with more complex descriptions; and (vi) a closer correspondence of IRS patterns in models using partitioning schemes to represent yield formation than in those using a harvest index.Such results can inform future crop modelling studies that seek to exploit the diversity of multi-model ensembles, by distinguishing ensemble members that span a wide range of responses as well as those that display implausible behaviour or strong mutual similarities.
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| 18. |
- Hansson, Helena, et al.
(författare)
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A framework to assess the resilience of farming systems
- 2019
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 176
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural systems in Europe face accumulating economic, ecological and societal challenges, raising concerns about their resilience to shocks and stresses. These resilience issues need to be addressed with a focus on the regional context in which farming systems operate because farms, farmers' organizations, service suppliers and supply chain actors are embedded in local environments and functions of agriculture. We define resilience of a farming system as its ability to ensure the provision of the system functions in the face of increasingly complex and accumulating economic, social, environmental and institutional shocks and stresses, through capacities of robustness, adaptability and transformability. We (i) develop a framework to assess the resilience of farming systems, and (ii) present a methodology to operationalize the framework with a view to Europe's diverse farming systems. The framework is designed to assess resilience to specific challenges (specified resilience) as well as a farming system's capacity to deal with the unknown, uncertainty and surprise (general resilience). The framework provides a heuristic to analyze system properties, challenges (shocks, long-term stresses), indicators to measure the performance of system functions, resilience capacities and resilience-enhancing attributes. Capacities and attributes refer to adaptive cycle processes of agricultural practices, farm demographics, governance and risk management. The novelty of the framework pertains to the focal scale of analysis, i.e. the farming system level, the consideration of accumulating challenges and various agricultural processes, and the consideration that farming systems provide multiple functions that can change over time. Furthermore, the distinction between three resilience capacities (robustness, adaptability, transformability) ensures that the framework goes beyond narrow definitions that limit resilience to robustness. The methodology deploys a mixed-methods approach: quantitative methods, such as statistics, econometrics and modelling, are used to identify underlying patterns, causal explanations and likely contributing factors; while qualitative methods, such as interviews, participatory approaches and stakeholder workshops, access experiential and contextual knowledge and provide more nuanced insights. More specifically, analysis along the framework explores multiple nested levels of farming systems (e.g. farm, farm household, supply chain, farming system) over a time horizon of 1-2 generations, thereby enabling reflection on potential temporal and scalar trade-offs across resilience attributes. The richness of the framework is illustrated for the arable farming system in Veenkolonien, the Netherlands. The analysis reveals a relatively low capacity of this farming system to transform and farmers feeling distressed about transformation, while other members of their households have experienced many examples of transformation.
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| 19. |
- Hansson, Helena, et al.
(författare)
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Impact of Covid-19 on farming systems in Europe through the lens of resilience thinking
- 2021
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 191
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Tidskriftsartikel (refereegranskat)abstract
- Context: Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis. Objective: This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment. Methods: The 11 farming systems included have been analysed since 2017. This allows a comparison of preCovid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns. Results and conclusions: Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on shortterm robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability. Significance: Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.
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| 20. |
- Hansson, P.-A., et al.
(författare)
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Self-sufficiency of motor fuels on organic farms : Evaluation of systems based on fuels produced in industrial-scale plants
- 2007
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 94:3, s. 704-714
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present work was to evaluate systems for making organic farms self-sufficient in bio-based fuels. The energy efficiency and environmental load for systems based on rape methyl ester (RME), ethanol and biogas produced by processing raw material from the farm in industrial-scale plants were evaluated using a life cycle perspective. Eventual constraints when implementing the systems in practice were also identified and the farmer's costs for the systems estimated. The RME scenario showed some good characteristics; the energy efficiency and potential effects on global warming were favourable, the technology well known and no engine modifications were necessary. However, the high price of the organically produced rapeseed made the fuel expensive. The ethanol scenario provided fuel at a comparatively low cost, but the energy efficiency was low and existing engines would have to be modified. The biogas scenario was not as economically advantageous, due to high costs for storage and transport of the biogas and the extensive tractor modifications needed. The calculations further showed that systems based on so-called exchange of fuels, i.e. when the farm produces raw material for one type of biofuel, but instead uses another type of biofuel more suitable for its own tractors, were an economically favourable way of supplying the organic farms with 'self-produced' bio-based fuels. The exchange scenario based on delivery of organic wheat to a large-scale plant and use of RME at the farm was somewhat more expensive than scenarios based on production of biogas raw material at the farm. However, the wheat/RME system has the advantage of being possible to put into practice immediately, since industrial-scale wheat ethanol plants are in operation and RME fuel is available on the market. © 2007 Elsevier Ltd. All rights reserved.
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| 21. |
- Henryson, K., et al.
(författare)
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Accounting for long-term soil fertility effects when assessing the climate impact of crop cultivation
- 2018
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Ingår i: Agricultural Systems. - : Elsevier. - 0308-521X .- 1873-2267. ; 164, s. 185-192
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Tidskriftsartikel (refereegranskat)abstract
- Soil organic carbon (SOC) dynamics influence the climate impact of crop cultivation, both through affecting net carbon exchange between the soil and the atmosphere and through affecting soil fertility. Higher soil fertility can enhance yield, and consequently make more plant residues available for carbon sequestration in the soil. This feedback mechanism between SOC and yield is commonly not included when assessing the environmental impact of crop production using system analysis tools like life cycle assessment (LCA). Therefore, this study developed a modelling framework where the SOC-yield feedback mechanism is included in climate impact assessment of crop cultivation, and which could be applied in LCAs. The framework was constructed by combining a model for SOC dynamics, yield response to SOC changes in a Swedish long-term field experiment and climate impact assessment. The framework employs a dynamic approach, with a time-distributed emissions inventory and a time-dependent climate impact assessment model, complemented by the most common climate metric, global warming potential (GWP). A case study applying the framework to barley cultivation was performed to explore the quantitative effect of including the feedback mechanism on the calculated climate impact. The case study involved simulating a fertiliser-induced 10% yield increase during one year and assessing the climate impact over 100 years. The effect of solely including SOC dynamics without the yield response to SOC decreased climate impact per kg barley by about three-fold more than only accounting for the 10% temporary yield increase. When the feedback mechanism was included, the estimated climate impact decreased five-fold more than when SOC changes were not included. These results show that SOC changes affect the climate impact of cultivation, not only through affecting net CO2 exchanges between soil and atmosphere, as previously acknowledged by other studies, but also through changing the system performance. The quantitative results obtained in this study show that this could be an important aspect to include in order to avoid introducing systematic error when assessing the long-term climate impact of crop management changes that affect yield or SOC dynamics.
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| 22. |
- Hessle, Anna, et al.
(författare)
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Combining environmentally and economically sustainable dairy and beef production in Sweden
- 2017
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Ingår i: Agricultural Systems. - : Elsevier Ltd. - 0308-521X .- 1873-2267. ; 156, s. 105-114
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Tidskriftsartikel (refereegranskat)abstract
- To achieve a more sustainable food sector, a supply chain approach is needed. In this study, experts in different areas along supply chains co-operated in an interactive process to define future environmentally sustainable supply chains of milk and beef. The basis was to use existing techniques, to have production performance corresponding to the best quartile of today and to consider other sustainability aspects, such as economics. The work resulted in concrete descriptions of alternative product chains for delivered milk and beef. To also permit concrete descriptions of the latter part of the product chains, two consumer-packed end products were selected for monitoring, namely fresh milk and sirloin steak. The production systems investigated comprised cropping, livestock production, industrial processing and production, logistics, packaging and wastage and distribution, but not retailers or consumers. The study area was a Swedish county and the reference level was its production of milk and beef in 2012. The future product chains were assumed to deliver the same amounts of commodities as in 2012, but with reduced environmental impact. Primary production was required to be at least as profitable as today. Beside description of the current situation, three alternative scenarios were created, focusing on delivery of ecosystem services, plant nutrient circulation and minimising climate impact, respectively. Life cycle assessments were performed for these four scenarios (reference plus three alternative scenarios) for single-product chains and county-wide. Furthermore, production costs in primary production were calculated for the four scenarios. The results revealed great potential to reduce the negative environmental impact of Swedish dairy and beef production at current volumes, irrespective of whether ecosystem services, plant nutrient circulation or climate impact is in focus. The single most important factor for decreased environmental impact for livestock production was increased production efficiency. Measures in agriculture, especially concerning feeds, were critical, but actions in processing and distribution also contributed. All alternative scenarios resulted in lower production costs than at present. It was obvious that as dairy and beef systems are connected, the potential for their environmental improvement must be analysed together. In conclusion, increased efficiency can decrease the negative environmental impact of Swedish cattle production and also reduce costs to the farmer.
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| 23. |
- Hidalgo, Francisco, et al.
(författare)
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Digitalization, sustainability, and coffee. Opportunities and challenges for agricultural development
- 2023
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Ingår i: Agricultural Systems. - 0308-521X. ; 208
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Digital technologies have the potential to address several sustainability challenges of the coffee value chain, however, given potential backlash consequences, this process must be assessed thoroughly. Descriptions of digital tools designed for this value chain have been presented in the literature, however, a critical examination of socio-environmental consequences of the process of digitalization is still lacking. OBJECTIVE: Using a socio-technical approach, this article examines innovation pathways proposed by the process of digitalization in the coffee value chain and identifies the opportunities and challenges of these pathways to contribute to sustainability goals in this value chain. METHODS: Technical characteristics of 20 digital tools oriented to the coffee producing sector are examined. We carried out a review of secondary information and conducted online semi-structured interviews with developers of these tools. Qualitative analyses of these characteristics were conducted across three themes: 1) knowledge and value systems represented, 2) power structures, 3) effective use of digital technology. RESULTS AND CONCLUSIONS: Our analysis identified two digitalization pathways that are likely to affect different dimensions of sustainability. On the one hand, digital advisory services are focused on the diffusion of conventional agricultural practices to optimize production for a commodity market. On the other hand, trade platforms and traceability systems are associated with enhanced visibility of producers to facilitate their participation in differentiated markets. However, access barriers to technologies create asymmetrical participation of producers in these scenarios. Additionally, evidence shows that, more than a revolution, digitalization of the coffee value chain is about optimization of production based on the use of synthetic inputs and of traditional extension models, and more efficient social coordination within already centralized power structures. SIGNIFICANCE: The analytical framework based on the technical characteristics of digital tools and their interaction with social systems revealed that sustainability outcomes derived from the process of digitalization in the coffee value chain are far from being straightforward. Considering digital technologies not as a homogeneous category, but as a configuration of different technical arrays, each one with distinctive patterns and impacts, provides a more nuanced understanding of the role of digitalization for agricultural development.
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| 24. |
- Huhtanen, Pekka
(författare)
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Dairy farm nutrient management model. 1. Model description and validation
- 2011
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 104, s. 371-382
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Tidskriftsartikel (refereegranskat)abstract
- Intensive dairy farming results in significant phosphorus (P) emission to the environment. Field data indicates that farm-gate P surplus is highly positive in Finland and strategies to mitigate the surplus are needed. The objectives of this study were to build a P cycle model for dairy farms (1) and to validate the model with independent field data (2). The dairy farm nutrient management model ("Lypsikki") described in this paper includes three sub-models: (1) soil and crop, (2) dairy herd and (3) manure management. The model is based on empirical regression equations allowing estimations of crop and milk yields in response to increased fertilisation and nutrient supply, respectively. In addition, the model includes a dynamic simulation model of the dairy herd structure and calculation of the farm-gate nutrient surplus. The model was validated with independent annual (average for 1-4 years) farm-gate P surplus data from 21 dairy farms. Model simulations were conducted using two levels of soil productivity, mean (M) and low (L). The model validation indicated a strong relationships between model-predicted and observed farm-gate P surplus: (M: R(2) = 0.77 and L: R(2) = 0.80). The line bias between the model-predicted and observed data was negligible and insignificant (P > 0.6) suggesting a robustness of the model. The mean biases were relatively high and significant (M: 4.7 and L: 1.8 kg/ha, P < 0.001), but evidently related to overestimation of crop yields that has to be taken into account when using the model on a single farm. The prediction error of the model (observed minus predicted P surplus) was significantly correlated to the difference between simulated and observed P import in feeds (M: R(2) = 0.55 and L: R(2) = 0.51). This suggests either that all the dairy farms did not fully exploit the possibilities in the crop production or that all the model assumptions are not correct. The effects of purchased feed and fertiliser P and exported milk P (per cow or cropping area) on farm-gate P surplus were of the same magnitude in both observed and simulated data. This implies that the model developed can be used as a management decision tool to find strategies to mitigate P surplus on dairy farms. (C) 2011 Elsevier Ltd. All rights reserved.
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| 25. |
- Huhtanen, Pekka
(författare)
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Dairy farm nutrient management model. 2. Evaluation of different strategies to mitigate phosphorus surplus
- 2011
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X .- 1873-2267. ; 104, s. 383-391
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Tidskriftsartikel (refereegranskat)abstract
- To reduce (P) surpluses on dairy farms and thereby the risk of P losses to natural waters we studied different management alternatives by a nutrient balance model described in the companion paper. The strategies evaluated mitigating the P surpluses were: mineral P fertilisation, dietary mineral P supplementation, replacement rate, animal density, production level, feeding intensity, dietary P concentration and nutrient efficiency in crop production. Responses to several interventions (e.g. mineral P fertilisation, purchased feed P, replacement rate) were similar to those observed in Finnish field studies. Reducing or completely giving up the use of purchased mineral P fertilisers was the most efficient measure to reduce P surplus. The slope between the amount of mineral fertilisers and P surplus was 0.98-0.99 (in the field data 1.0). Increased animal density resulted in a greater P surplus, but the slope between P input from purchased feed and surplus was considerably smaller (0.65) than that of P fertilisation. Increasing milk yield with improved genetic potential of the cows would have minimal effects on P surplus per unit of product, but it would increase P surplus per hectare. When the intensity of energy and protein feeding was increased, P surplus rose markedly both per unit of product and hectare. This is (1) due to increased dietary P concentration and (2) due to smaller marginal production responses than those calculated from feeding standards. Reducing dietary P concentration by constraining P excess per kg milk in least-cost ration formulation improved P efficiency in milk production and dairy farming system. However, feed cost increased as low P energy (sugar-beet pulp) and protein (soybean meal) supplements are more expensive than cereal grains or rapeseed feeds. Improving the nutrient use efficiency in crop production had a strong influence in the whole-farm efficiency and P surplus. The modelling results showed that Finnish dairy farms have a great potential to improve P efficiency and reduce P losses to the environment, even by increasing production intensity (milk/ha). It is concluded that the most cost-effective scenario to mitigate P surpluses at a dairy farm would be to reduce or give up the use of mineral P as fertilisers and supplements, and to improve the use of present soil P reserves. (C) 2011 Elsevier Ltd. All rights reserved.
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