| 1. |
- Andersson, Georg, et al.
(author)
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Effects of farming intensity, crop rotation and landscape heterogeneity on field bean pollination
- 2014
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 1873-2305 .- 0167-8809. ; 184, s. 145-148
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Journal article (peer-reviewed)abstract
- Organic farming has the potential to enhance ecosystem services such as crop pollination. However, it is not known if a similar effect can be generated on conventional farms, without reducing external inputs such as inorganic fertilizers and pesticides, by using more complex crop rotations including ley for animal fodder production. In two separate designs, both located in southern Sweden, we tested if local organic farming and the landscape proportion of conventionally managed leys, along a landscape heterogeneity gradient, affected the pollination success of field bean. The number of developed pods was higher on organic farms compared to conventional ones. Development of beans, which demands high pollination efficiency, increased with increasing landscape heterogeneity, but only on organic farms. Increasing proportion of ley on conventional farms did not significantly influence the development of beans. The number of developed pods was not affected by the proportion of ley in the landscape. Our results demonstrate that in order to maximize pollination success it is important to improve both field management and preserve semi-natural habitats in the agricultural landscape. Reducing farming intensity with conventionally managed leys does not seem to be as effective as organic farming for delivering crop pollination services. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Benegas, Laura, et al.
(author)
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Effects of trees on infiltrability and preferential flow in two contrasting agroecosystems in Central America
- 2014
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In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 183, s. 185-196
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Journal article (peer-reviewed)abstract
- We tested the hypothesis that trees have measurable effects on infiltrability, macroporosity, and preferential flows in agrosilvopastoral systems. Managing agricultural systems for water conservation is a critical component of sustainable systems. We investigated the relationship between infiltrability and the distance to the nearest tree, and whether differences in macroporosity can account for differences in infiltrability.In both systems, preferential soil water flows were dominant compared to matrix flow. Trees in the pasture landscape improved infiltrability and preferential flow but had no significant effect in the coffee agroforestry system. After comparing rainfall intensity and frequency data to the measured infiltrability values, we conclude that trees in the pasture system reduce surface runoff at the highest observed rainfall intensities (>50 mm h(-1)). The volcanic soils of the coffee plantation are less degraded and their high natural permeability has been maintained. Since the coffee plants at this site are established (40 years) perennial vegetation with substantial residues and extensive root systems like trees, they improve soil physical properties similarly to trees.Trees increase hydrologic services in pasture lands, a rapidly expanding land use type across Latin America, and therefore may be a viable land management option for mitigating some of the negative environmental impacts associated with land clearing and animal husbandry. However, in land management practices where understorey perennial vegetation makes up a large proportion of the cover, such as for coffee agroforestry systems, the effect of trees on infiltration-related ecosystem services could be less pronounced (C) 2013 Elsevier B.V. All rights reserved.
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| 3. |
- Bolinder, Martin, et al.
(author)
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Long-term soil organic carbon and nitrogen dynamics in forage-based crop rotations in Northern Sweden (63-64 degrees N)
- 2010
-
In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 138, s. 335-342
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Journal article (peer-reviewed)abstract
- For carbon sequestration estimates it is necessary to evaluate effects of management practices on soil organic carbon (SOC) and nitrogen (SON) dynamics in a wide range of production systems and climatic zones. At higher latitudes with cold temperate climate, crop rotations dominated by forage are common and often highly productive-and the climate as well as the forage cropping systems favour large stocks of SOC and SON. The objective of this study was to estimate SOC and SON stock dynamics in the arable layer (0-25 cm) for different 6-year forage-based rotations using sampling data from three long-term field experiments in Northern Sweden. At the site with the lowest initial amount of SOC (8.2 kg C m(-2)), SOC stocks increased by 12 g C m(-2) yr(-1) over a 50-year period for the continuous forage rotation ('A'), which received ca. 10 Mg ha(-1) of cattle manure per year (wet mass). At the same site, SOC stocks were more or less at steady state in rotation 'B' with 4 years of forage and 2 years of annuals, receiving the same amount of manure. For rotation 'C' with 3 years of forage and receiving ca. 6.5 Mg ha(-1) of manure, the SOC stocks decreased by 18 g C m(-2) yr(-1,) while the SOC stocks for rotation 'D' with only annuals and no manure application decreased by 24 g C m(-2) yr(-1). At the other two sites, with higher initial SOC stocks (12.1 and 12.8 kg C m(-2)), the SOC stocks in all treatments decreased during a 30-year period, at a rate ranging from 11 to 95 g C m(-2) yr(-1). Similar trends were found for the change in SON stocks, although they were more variable. The topsoil SOC stocks were high compared to southern Sweden and regions of similar climate in northeast Canada, in particular for rotation A. These results indicate that the estimates of SOC and SON storage rate changes for a particular management system van vary widely within a small region of a given climatic zone. (C) 2010 Elsevier B.V. All rights reserved.
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| 4. |
- Chala, Workneh Bedada, et al.
(author)
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Long-term addition of compost and NP fertilizer increases crop yield and improves soil quality in experiments on smallholder farms
- 2014
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In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 195, s. 193-201
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Journal article (peer-reviewed)abstract
- Soil fertility decline due to low nutrient input is a constraint for sustainable agriculture in smallholder farming systems in Ethiopia. In this study, crop productivity and soil organic matter buildup were compared in soils receiving locally made compost, applied either alone or in combination with NP fertilizer. The experiments had four treatments: full dose of compost (C), full dose of fertilizer (F), half compost and half fertilizer (CF), and unfertilized control (control). The full dose of compost was equivalent to 2.4 t ha(-1) organic matter. The field study was conducted on four farm fields in the village Beseku, each representing different sub-villages. Participating farmers were selected based on their willingness and an assessment of dedication to carry out the experiment. The experiments, a randomized complete block design with three replications, were replicated across four farm fields. The treatments were repeated for six cropping seasons (years), and data on soil nutrient status and crop (maize, wheat, potato, and faba bean) harvests were collected. In the 0-10 cm soil layer, pH was (P < 0.05) lower in the F treatments than in the C and CF treatments. Compared with the F treatment, the soil organic carbon (SOC) and total nitrogen stocks increased (P < 0.05) by 4.60 and 0.42 t ha(-1) in C treatment, and by 4.74 and 0.45 t ha(-1) in CF treatment. Treatment effects on crop harvests were significant (P < 0.05) for all crops grown across the sites and seasons. The highest maize yield was obtained from CF, with relative harvest of 178% compared with the control and 126% compared with F, but was comparable to C. For wheat and potato, the yields obtained from CF, C and F were comparable. For faba bean, CF had a relative harvest of 145% over the control. Maize harvest was in the order of CF > F> C> control in the initial season, CF > C> F> control in the next three consecutive seasons, and C> CF> F> control in the final year of the experiment. The overall combined yield was in the order of CF > C> F> control for maize and faba bean, CF > F> C> control for potato, and F> CF > C> control for wheat. The addition of either compost alone or in combination with NP fertilizer improved soil properties and crop productivity, compared with control and only fertilizer addition. Therefore, compost addition can serve as a complement to fertilizer use and reduce dependence on mineral fertilizer in low-input crop production system. The apparent synergy between compost and fertilizer addition needs further research in order to be explained. (C) 2014 Elsevier B.V. All rights reserved.
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| 5. |
- Cheeke, Tanya
(author)
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Effect of Bacillus thuringiensis (Bt) maize cultivation history on arbuscular mycorrhizal fungal colonization, spore abundance and diversity, and plant growth
- 2014
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In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 195, s. 29-35
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Journal article (peer-reviewed)abstract
- Greenhouse studies have reported that maize expressing Bacillus thuringiensis (Bt) insecticidal toxins may have nontarget effects on symbiotic arbuscular mycorrhizal fungi (AMF), however, field studies have not detected the same pattern. This may be due to the short-term nature of previous field experiments, differences in soil properties between studies, or plant-soil feedbacks that influence AMF communities in roots and soil over time. In this field experiment, we used split plots to evaluate the effect of Bt or non-Bt maize cultivation history on AMF spore abundance, diversity, root colonization, and growth of seven different genotypes of Bt maize and five corresponding non-Bt parental (P) isolines. We found that Bt plants had higher leaf chlorophyll content when they were grown in plots that had been cultivated with Bt maize the previous year, and similarly, non-Bt plants had higher chlorophyll content when they were grown in plots with a non-Bt cultivation history, indicative of a positive feedback effect. There was a lower density of AMF spores in plots with a Bt maize cultivation history than in plots where P maize had been grown in the previous year, but no difference in spore diversity. Despite the differences in spore density, we found no significant differences in AMF colonization or root or shoot biomass between plots with a cultivation history of Bt and P maize. This study presents the first evidence of an effect of Bt maize cultivation on the soil ecosystem, but also provides further evidence that this effect is not necessarily large or easily detectable within the range of normal environmental variation. Management of agroecosystems will need to consider the potential effects of reduced numbers of AMF propagules in soil as this could have an effect on ecosystem processes including carbon sequestration, nutrient cycling, drought tolerance, soil aggregation, and plant resistance to pathogens. Taken together with greenhouse experiments, we can now make predictions on how Bt maize cultivation may affect AMF under different environmental conditions. (C) 2014 Elsevier B.V. All rights reserved.
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| 6. |
- Diekötter, Tim, et al.
(author)
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Landscape and management effects on structure and function of soil arthropod communities in winter wheat
- 2010
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 1873-2305 .- 0167-8809. ; 137:1-2, s. 108-112
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Journal article (peer-reviewed)abstract
- This study evaluates the impact of agricultural management (organic vs. conventional) and landscape context on species richness and abundance of five soilarthropod taxa (ground beetles, spiders, springtails, millipedes, woodlice) and associated ecosystem functions (soil biological activity, weed seed predation, litter decomposition). A significant interaction between management type and landscape context was revealed in several cases. Activity density of millipedes and wood lice and species richness of ground beetles were higher in fields where local and regional management types were complementary, indicating a beneficial effect of environmental heterogeneity. In addition, seed predation on arable weeds was higher in organically than conventionally managed fields. It is concluded that the effect of agricultural management on soilarthropod biodiversity and functioning is often context dependent. The diversity of functionally important taxa such as ground beetles and decomposers may be enhanced by increasing environmental heterogeneity, a measure that is also beneficial for other components of agrobiodiversity. Thus, in a conventional agricultural context even managing only a fraction of fields organically may help to increase environmental heterogeneity and thereby promote soilarthropod diversity and the associated ecosystem functions.
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| 7. |
- Dile, Yihun Taddele, et al.
(author)
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The role of water harvesting to achieve sustainable agricultural intensification and resilience against water related shocks in sub-Saharan Africa
- 2013
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 181, s. 69-79
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Research review (peer-reviewed)abstract
- Poverty alleviation in rural areas is a top priority for social and economic development, particularly against a backdrop of rising populations up to 2050 and to meet growing food demands in a rapidly urbanizing world. Sustainable intensification of agricultural techniques are therefore required, such as water management practices that result in higher agricultural production without causing severe environmental impacts, whilst at the same time improving resilience to drought and dry spells. Water harvesting practices have shown promising results in reducing risks, and improving yields whilst also delivering positive impacts on other ecosystems. However, before large scale implementation of water harvesting, further investigation of local downstream impacts are warranted. We conclude that water harvesting remains a promising option for sustainable agricultural intensification in the water scarce tropics, resulting in both risk reduction and yield improvements.
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| 8. |
- Eckersten, Henrik
(author)
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Coincidence of variation in yield and climate in Europe
- 2010
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In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 139, s. 483-489
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Journal article (peer-reviewed)abstract
- We aimed to characterise the coincidence of yield variations with weather variables for major field crops using long-term datasets and reveal whether there are commonalities across the European agricultural regions. Long-term national and/or regional yield datasets were used from 14 European countries (total of 25 regions). Crops studied were spring and winter barley and wheat, winter oilseed rape, potato and sugar beet. Relative yield deviations were determined for all crops. Meteorological data on monthly means for temperature variables, solar radiation, accumulated precipitation and evapotranspiration were provided for the relevant agricultural regions of each country for 1975-2008. Harmful effects of high precipitation during grain-filling in grain and seed crops and at flowering in oilseed rape were recorded. In potato reduced precipitation at tuber formation was associated with yield penalties. Elevated temperatures had harmful effects for cereals and rapeseed yields. (c) 2010 Elsevier B.V. All rights reserved.
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| 9. |
- Eggers, Sönke, et al.
(author)
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Landscape composition influences farm management effects on farmland birds in winter: A pan-European approach
- 2010
-
In: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 139, s. 571-577
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Journal article (peer-reviewed)abstract
- This study examined the effects of agricultural intensity, various farming practices, landscape composition and vegetation cover on the abundance and species richness of wintering farmland birds, assessed simultaneously across seven European regions.The abundance and species richness of wintering farmland birds were negatively affected by agricultural intensity. The effects of yield and farm type were interlinked. Of the 10 farming practices assessed, mechanical weeding and the amount of organic fertilizer applied negatively affected farmland birds, presumably due to reduced food availability on arable fields. Positive effects of organic farming on farmland birds proved to be limited to simplified landscapes. More farmland birds were observed in areas with more stubble, pasture and green manure crops. Species richness was higher in areas with more pasture.The results of this study show that farm management, vegetation cover and landscape composition all influence wintering farmland birds. Heterogeneous landscapes comprising arable crops as well as grasslands support most species of farmland birds in winter. The effectiveness of organic farming and agri-environment schemes depends on landscape composition. Therefore, different agri-environment schemes should be designed for different landscape types. (c) 2010 Elsevier B.V. All rights reserved.
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| 10. |
- Eriksson, Sofia, et al.
(author)
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Addressing semantics and historical data heterogeneities in cross-temporal landscape change analyses
- 2010
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In: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 139:139, s. 516-521
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Journal article (peer-reviewed)abstract
- The process of recreating historical land cover dynamics, needed to understand trends and transient states in ecosystems, includes difficulties such as the sensitivity of applied spatial analyses to heterogeneities in historical material. This paper compares the handling of quantitatively dominating categories in two matrix analyses of land cover change within a Swedish boreal landscape (1725–1859). The focus is on how inconsistencies between historical maps can be handled without violating the inherent semantic potential. The study shows that analyses of land cover support different indications of change depending on the treatment of dominating categories. The type of landscape and research questions in focus should therefore be part of choosing matrix method and classification scheme. The observed patterns need to be evaluated against drivers of change and semantic plasticity in classification schemes to separate ecological change from semantic confusion. This paper recommends aggregated classification schemes with maintained original relationships between categories in comprehensive analyses. However, no pathway is persistent over time and categories should be allowed to disappear and new to appear. Analysis of historical dynamics with extended transition matrixes is recommended to account for the dynamics of small categories in relation to dominating categories within a landscape.
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