| 1. |
- 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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| 2. |
- 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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| 3. |
- 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
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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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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
- 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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