| 1. |
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| 2. |
- Carlsson, Georg, et al.
(författare)
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Perennial species mixtures for multifunctional production of biomass on marginal land
- 2017
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1693 .- 1757-1707. ; 9:1, s. 191-201
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Tidskriftsartikel (refereegranskat)abstract
- Multifunctional agriculture provides noncommodity functions and services along with food, feed and bioenergy feedstocks, for example by preserving or promoting biodiversity, improving soil fertility, mitigating climate change and environmental degradation, and contributing to the socio-economic viability of rural areas. Producing biomass for bioenergy from low-input perennial species mixtures on marginal land has the potential to support biodiversity and soil carbon sequestration in synergy with greenhouse gas mitigation. We compared biomass production in species-rich mixtures of perennial grasses, legumes and forbs with pure-stand grasses and relatively species-poor mixtures under different nitrogen fertilization regimes. Field experiments were performed on different types of marginal land, that is agricultural field margins and land with poor soil fertility, at four sites in southernmost and western Sweden. Biomass production was measured for three years in perennial grasses grown as pure stands, in legume-grass mixtures, and legume-grass-forb mixtures across a species richness gradient. In unfertilized species-rich mixtures, average biomass yields per experimental site and year were in the range from 3 to 9 metric ton DM ha−1 yr−1. While the most productive pure-stand grasses fertilized with 60–120 kg N ha−1 yr−1 often produced higher biomass yields than unfertilized mixtures, these differences were generally smaller than the variations between years and sites. Calculations of climate impact using the harvested biomass for conversion to biogas as vehicle fuel showed that the average greenhouse gas emissions per energy unit were about 50% lower in unfertilized systems than in treatments fertilized with 100–120 kg N ha−1 yr−1. Our findings thereby show that unfertilized species-rich perennial plant mixtures on marginal land provide resource-efficient biomass production and contribute to the mitigation of climate change. Perennial species mixtures managed with low inputs thus promote synergies between productivity and biodiversity in the perspective of climate-smart and multifunctional biomass production.
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| 3. |
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| 4. |
- Steen Jensen, Camilla, et al.
(författare)
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Cerebrospinal Fluid Amyloid Beta and Tau Concentrations Are Not Modulated by 16 Weeks of Moderate- to High-Intensity Physical Exercise in Patients with Alzheimer Disease.
- 2016
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 42:3-4, s. 146-158
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Tidskriftsartikel (refereegranskat)abstract
- Physical exercise may have some effect on cognition in patients with Alzheimer disease (AD). However, the underlying biochemical effects are unclear. Animal studies have shown that amyloid beta (Aβ), one of the pathological hallmarks of AD, can be altered with high levels of physical activity.The objective of this study was to elucidate the effect of 16 weeks of moderate- to high-intensity physical exercise on the biomarkers of AD, with special emphasis on the amyloidogenic pathway.From a total of 53 patients with AD participating in the Preserving Cognition, Quality of Life, Physical Health and Functional Ability in Alzheimer's Disease: The Effect of Physical Exercise (ADEX) study we analyzed cerebrospinal fluid samples for Aβ species, total tau (t-tau), phosphorylated tau (p-tau) and soluble amyloid precursor protein (sAPP) species. We also assessed the patients for apolipoprotein E ε4 (ApoE ε4) genotype.We found no effect of 16 weeks of physical exercise on the selected biomarkers, and no effect of ApoE ε4 genotype.Our findings suggest that the possible effect of physical exercise on cognition in patients with AD is not due to modulation of Aβ, t-tau, p-tau and sAPP species.
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| 5. |
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| 6. |
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| 7. |
- Atar, Dan, et al.
(författare)
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Rationale and Design of the 'MITOCARE' Study: A Phase II, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety and Efficacy of TRO40303 for the Reduction of Reperfusion Injury in Patients Undergoing Percutaneous Coronary Intervention for Acute Myocardial Infarction
- 2012
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Ingår i: Cardiology. - : S. Karger AG. - 1421-9751 .- 0008-6312. ; 123:4, s. 201-207
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Tidskriftsartikel (refereegranskat)abstract
- Treatment of acute ST-elevation myocardial infarction (STEMI) by reperfusion using percutaneous coronary intervention (PCI) or thrombolysis has provided clinical benefits; however, it also induces considerable cell death. This process is called reperfusion injury. The continuing high rates of mortality and heart failure after acute myocardial infarction (AMI) emphasize the need for improved strategies to limit reperfusion injury and improve clinical outcomes. The objective of this study is to assess safety and efficacy of TRO40303 in limiting reperfusion injury in patients treated for STEMI. TRO40303 targets the mitochondrial permeability transition pore, a promising target for the prevention of reperfusion injury. This multicenter, double-blind study will randomize patients with STEMI to TRO40303 or placebo administered just before balloon inflation or thromboaspiration during PCI. The primary outcome measure will be reduction in infarct size (assessed as plasma creatine kinase and troponin I area under the curve over 3 days). The main secondary endpoint will be infarct size normalized to the myocardium at risk (expressed by the myocardial salvage index assessed by cardiac magnetic resonance). The study is being financed under an EU-FP7 grant and conducted under the auspices of the MITOCARE research consortium, which includes experts from clinical and basic research centers, as well as commercial enterprises, throughout Europe. Results from this study will contribute to a better understanding of the complex pathophysiology underlying myocardial injury after STEMI. The present paper describes the rationale, design and the methods of the trial. Copyright (c) 2012 S. Karger AG, Basel
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| 8. |
- Bargaz, Adnane, et al.
(författare)
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Faba bean variety mixture can modulate faba bean-wheat intercrop performance under water limitation
- 2021
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Ingår i: Frontiers in Agronomy. - : Frontiers Media SA. - 2673-3218. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Commercial legume varieties vary in terms of their drought tolerance when grown as sole crops, though relatively little is known about how legume variety selection affects cereal–legume intercrop performance under drought conditions. This study aims to test the hypothesis that positive rhizosphere interactions in faba bean–wheat intercrops will confer a “buffering capacity” on faba bean and wheat performance under water stress and that this effect will (i) depend on faba bean varietal selection and (ii) be enhanced with increasing faba bean varietal diversity. In a greenhouse experiment, three commercial faba bean (Vicia faba L.) varieties [Gloria (G), Alexia (A), Julia (J)] were grown in sole crop or intercropped with spring wheat (Triticum aestivum L.) under well-watered or water-stress conditions. Under intercropping, either one, two, or all three faba bean varieties were grown together with wheat to test the effect of intraspecific diversity on a cereal–legume intercrop performance. Consistent with the proposed hypothesis, we found that, under well-watered and water-stress conditions, wheat and faba bean shoot biomass production and nitrogen (N) acquisition improved with intercropping and that faba bean variety and variety mixture strongly modulated the intercropping effect. Interestingly, in both well-watered and water-stress conditions, wheat dry biomass and N accumulation were greatest in intercrops containing Gloria, while nodule number, nodule weight, and N accumulation in faba bean were greatest for intercrops containing Alexia and Julia (AJ). The effect of varietal diversity was inconsistent. Intercrops with two faba bean varieties tended to have positive or neutral effects on measured wheat and faba bean variables. However, overall performance under intercropping was generally reduced when all three faba bean varieties were planted with wheat. The effect of faba bean species diversity can buffer faba bean–wheat intercrop performance against water stress, and intercropping tended to have positive or neutral effects on the measured wheat and faba bean variables, notably with two-varietal faba bean mixtures.
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| 9. |
- Bargaz, Adnane, et al.
(författare)
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Intercropping of faba bean with wheat under low water availability promotes faba bean nodulation and root growth in deeper soil layers
- 2015
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Ingår i: Procedia Environmental Sciences. - : Elsevier BV. - 1878-0296. ; 29, s. 111-112
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Konferensbidrag (refereegranskat)abstract
- The symbiotically fixed N is advantageous to legumes growing under N-limiting conditions, and is also potentially beneficial for subsequent or associated non-legume crops(1, 2). However, under stressful conditions such as water limitation and low nutrient availability, legumes may lose the distinct advantage of an unlimited source of symbiotic N-2 (3, 4,) (5) Belowground niche complementarity in legume-cereal intercrops may improve resource use efficiency and adaptability to environmental constraints, but effects of water limitation on legume rooting and nodulation patterns is poorly understood. To advance our knowledge of mechanisms involved in water stress response, faba bean (Vicia faba L., FB) and wheat (Triticum aestivum L.) were grown as mono- and intercrops in soil-filled plexiglass rhizoboxes under water sufficiency (80% of field capacity; FC) and water stress (30% of FC). Water stress decreased shoot biomass in both monocropped and intercropped FB, as well as root length in monocropped FB. Intercropping increased both shoot dry weight and height of FB irrespective of water treatment, while increased root biomass and length in intercropped FB was observed only under water stress. No significant effects of crop or water treatment were found on wheat growth parameters. Intercropping increased overall nodulation (nodule number and nodule dry weight; NDW) regardless of water availability. However spatial patterns of nodulation differed between water treatments: top-15-cm NDW and number increased (27 and 33%, respectively) in sufficiently-watered intercropped FE, while NDW in the same soil layer significantly decreased (45%) in water-stressed intercropped FE. In contrast, below-15-cm NDW and number significantly increased in intercropped FE under both water levels. This enhanced nodulation in the deeper soil layer and the associated increase in root and shoot growth provides evidence for a shift in niche occupancy that improves FB performance when exposed to water limitation in intercropping. (C) 2015 The Authors. Published by Elsevier B.V.
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| 10. |
- Bargaz, Adnane, et al.
(författare)
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Nodulation and root growth increase in lower soil layers of water-limited faba bean intercropped with wheat
- 2016
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Ingår i: Journal of Plant Nutrition and Soil Science. - : Wiley. - 1436-8730 .- 1522-2624. ; 179, s. 537-546
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Tidskriftsartikel (refereegranskat)abstract
- Below-ground niche complementarity in legume-cereal intercrops may improve resource use efficiency and root adaptability to environmental constraints. However, the effect of water limitation on legume rooting and nodulation patterns in intercropping is poorly understood. To advance our knowledge of mechanisms involved in water-limitation response, faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) were grown as mono- and intercrops in soil-filled plexiglass rhizoboxes under water sufficiency (80% of water-holding capacity) and water limitation (30% of water-holding capacity). We examined whether intercropping facilitates below-ground niche complementarity under water limitation via interspecific root stratification coupled with modified nodulation patterns. While no significant treatment effects were measured in intercropped wheat growth parameters, water limitation induced a decrease in shoot and root biomass of monocropped wheat. Likewise, shoot biomass and height, and root length of monocropped faba bean significantly decreased under water limitation. Conversely, water limitation stimulated root biomass of intercropped faba bean in the lower soil layer (15-30 cm soil depth). Similarly, total nodule number of faba bean roots as well as nodule number in the lower soil layer increased under intercropping regardless of water availability. Under water limitation, intercropping also led to a significant increased nodule biomass (48%) in the lower soil layer as compared to monocropping. The enhanced nodulation in the lower soil layer and the associated increase in root and shoot growth provides evidence for a shift in niche occupancy when intercropped with wheat, which improves water-limited faba bean performance.
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| 11. |
- Bargaz, Adnane, et al.
(författare)
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Species interactions enhance root allocation, microbial diversity and P acquisition in intercropped wheat and soybean under P deficiency
- 2017
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 120, s. 179-188
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Tidskriftsartikel (refereegranskat)abstract
- Belowground interactions in grain legume-cereal intercrops may improve resource acquisition and adaptation to environmental constraints such as phosphorus (P) deficiency. To advance the knowledge of belowground facilitative mechanisms involved in P-deficiency tolerance (root allocation, biochemical and microbial responses), soybean (Glycine max) and wheat (Triticum aestivum) were grown as monocrops and intercrops under P-deficiency and P-sufficiency conditions in soil-filled rhizoboxes. The hypothesis was that intercropping stimulates root microbial diversity, root biomass allocation and P-hydrolyzing acid phosphatases (APase) activity in roots under P-deficient conditions. Total root dry weight (RDW), length, and surface area significantly increased in P-deficient intercropped wheat and soybean. Greater root allocation to deeper soil layers was evident for P-deficient intercropped wheat. Shallow roots of intercropped wheat exhibited highly stimulated APase activity under P-deficient conditions while shallow roots of monocropped soybean exhibited higher APase activity in comparison to deeper roots, irrespective of P treatment. Root fungal diversity was significantly (p < 0.05) higher in intercropped wheat, and was significantly correlated with RDW, root APase activity, shoot P, and soil available P (rho = 0.24, p= 0.01). Root bacterial diversity was higher in both intercrops, and was significantly correlated with RDW and shoot N concentration. The observed shifts in root microbial diversity, root biomass allocation and APase activity provide explanatory mechanisms of relationships between rhizosphere heterogeneity and pathways for increased P acquisition in diversified crops. Advanced belowground metabolomics on root microbial communities are required to reveal the beneficial effect of root microorganisms in associations of different crop species.
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| 12. |
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| 13. |
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| 14. |
- Carlsson, Georg, et al.
(författare)
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Host-specific competitiveness to form nodules in Rhizobium leguminosarum symbiovar viciae
- 2020
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 226, s. 555-568
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Tidskriftsartikel (refereegranskat)abstract
- Fabeae legumes such as pea and faba bean form symbiotic nodules with a large diversity of soil Rhizobium leguminosarum symbiovar viciae (Rlv) bacteria. However, bacteria competitive to form root nodules (CFN) are generally not the most efficient to fix dinitrogen, resulting in a decrease in legume crop yields. Here, we investigate differential selection by host plants on the diversity of Rlv. A large collection of Rlv was collected by nodule trapping with pea and faba bean from soils at five European sites. Representative genomes were sequenced. In parallel, diversity and abundance of Rlv were estimated directly in these soils using metabarcoding. The CFN of isolates was measured with both legume hosts. Pea/faba bean CFN were associated to Rlv genomic regions. Variations of bacterial pea and/or faba bean CFN explained the differential abundance of Rlv genotypes in pea and faba bean nodules. No evidence was found for genetic association between CFN and variations in the core genome, but variations in specific regions of the nod locus, as well as in other plasmid loci, were associated with differences in CFN. These findings shed light on the genetic control of CFN in Rlv and emphasise the importance of host plants in controlling Rhizobium diversity.
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| 15. |
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| 16. |
- Carlsson, Georg, et al.
(författare)
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The 4C Approach as a way to understand species interactions determining intercropping productivity
- 2021
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Ingår i: Frontiers of Agricultural Science and Engineering. - 2095-7505 .- 2095-977X. ; 8, s. 387-399
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Tidskriftsartikel (refereegranskat)abstract
- Modern agriculture needs to develop transition pathways toward agroecological, resilient and sustainable farming systems. One key pathway for such agroecological intensification is the diversification of cropping systems using intercropping and notably cereal-grain legume mixtures. Such mixtures or intercrops have the potential to increase and stabilize yields and improve cereal grain protein concentration in comparison to sole crops. Species mixtures are complex and the 4C approach is both a pedagogical and scientific way to represent the combination of four joint effects of Competition, Complementarity, Cooperation, and Compensation as processes or effects occurring simultaneously and dynamically between species over the whole cropping cycle. Competition is when plants have fairly similar requirements for abiotic resources in space and time, the result of all processes that occur when one species has a greater ability to use limiting resources (e.g., nutrients, water, space, light) than others. Complementarity is when plants grown together have different requirements for abiotic resources in space, time or form. Cooperation is when the modification of the environment by one species is beneficial to the other(s). Compensation is when the failure of one species is compensated by the other(s) because they differ in their sensitivity to abiotic stress. The 4C approach allows to assess the performance of arable intercropping versus classical sole cropping through understanding the use of abiotic resources.
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| 17. |
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| 18. |
- Chongtham Iman, Raj, et al.
(författare)
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Translating the multi-actor approach to research into practice using a workshop approach focusing on species mixtures
- 2021
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Ingår i: Frontiers of Agricultural Science and Engineering. - 2095-7505 .- 2095-977X. ; 8, s. 460-473
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Tidskriftsartikel (refereegranskat)abstract
- The EIP-Agri multiactor approach was exemplified during a 3-day workshop with 63 project participants from the EU H2020 funded project "Redesigning European cropping systems based on species MIXtures". The objective was to share firsthand experience of participatory research among researchers who were mostly not familiar with this approach. Workshop participants were divided into smaller multidisciplinary groups and given the opportunity to interact with representatives from eight actor positions in the value chain of the agrifood cooperative Terrena located in Western France. The four stages of the workshop were: (1) key actor interviews, (2) sharing proposed solutions for overcoming barriers, and (3) developing possible interdisciplinary concepts. Expressions of frustration were recorded serving both as a motivation for group members to become more aware of the scientific concerns and practices of their colleagues, as well as a recognition that some researchers have better skills integrating qualitative approaches than others. Nevertheless, the workshop format was an effective way to gain a common understanding of the pertinent issues that need to be addressed to meet overall multiactor-approach objectives. Working with the actor networks was identified and emphasized as a means to overcome existing barriers between academia and practice in order to coproduce a shared vision of the benefits of species mixture benefits. (C) The Author(s) 2021. Published by Higher Education Press.
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| 19. |
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| 20. |
- Dhamala, Nawa Raj, et al.
(författare)
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Intercropping of oat and pea to address field-scale soil heterogeneity
- 2021
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Ingår i: Aspects of Applied Biology. - 0265-1491. ; 146, s. 275-280
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Growing grain legumes is challenging due to a high spatial and temporal variability in yield caused by various biotic and abiotic factors, which may be compensated and/or minimised by intercropping (IC) with cereals. However, little is known about the effect of field-scale soil spatial variability on competitive interactions between the IC components, resource use and crop yield performance. A field experiment was conducted to determine how intercropping (IC) of oat (Avena sativa L.) and field pea (Pisum sativum L.) affects crop yield, and balances the field-scale heterogeneity in soil conditions compared to sole crops (SCs). The soil parameters and crop yields varied considerably across the field. The oat-pea IC showed less field-scale variability in yield and suppressed weeds more strongly than pea SC. The study will provide an important insight into how IC can address the issue of crop yield variability and weed growth arising from the variable soil conditions.
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| 21. |
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| 22. |
- Dimitrova Mårtensson, Linda-Maria, et al.
(författare)
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Agronomic performance, nitrogen acquisition and water-use efficiency of the perennial grain crop Thinopyrum intermedium in a monoculture and intercropped with alfalfa in Scandinavia
- 2022
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Ingår i: Agronomy for Sustainable Development. - : Springer Science and Business Media LLC. - 1774-0746 .- 1773-0155. ; 42
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Tidskriftsartikel (refereegranskat)abstract
- The perennial forage grass Thinopyrum intermedium (Host) Barkworth & Dewey, commonly known as intermediate wheatgrass (IWG) or by the commercial name Kernza (TM), is being developed as a perennial grain crop, i.e. being bred for its improved agronomic performance and food qualities. Intercropping legumes and grasses is a strategy for improving resource use and sustainability in cropping systems. Here, we show for the first time the agronomic performance of IWG as a perennial cereal grown as a monocrop and as an intercrop (alternate row, 0.5:0.5) with Medicago sativa L. (alfalfa/lucerne) in southern Sweden. The seeds of cycle 3 IWG were accessed from The Land Institute (TLI) of Salinas, Kansas, USA, and used to establish a local seed production plot (in 2014) for the establishment of the perennial systems (in 2016) utilised in this study. Both the monocrop and intercrop were sown with 25 cm row spacing with alternate rows of IWG and alfalfa in the intercrop (i.e. replacement design) with unknown sowing density. Intercropping provided sustained IWG grain production under the dry conditions of 2018, but also in the following year. This was evidently associated with a higher nitrogen accumulation in intercropped practice. Thus, intercropping seems to have stabilised the IWG grain production in the dry conditions of 2018, when the grain production in the intercrop was similar to that of the monocrop in the same year. This result was further supported by the lower discrimination against C-13 (as an indicator of water use efficiency) in the intercrop components compared to the sole crop in 2018. The lower discrimination indicates high water use efficiency in the intercropped IWG in comparison to the IWG in monoculture, and we conclude that intercropping perennial cereal grain crops with legumes provides better growing conditions in terms of nitrogen acquisition, and water status, to cope with more extreme drought spells expected from climate change.
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| 23. |
- Dimitrova Mårtensson, Linda-Maria, et al.
(författare)
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En perenn revolution i jordbruket?
- 2020
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Ingår i: YstadNatur.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Det sägs att perenna, dvs. fleråriga, grödor är nästa revolution i jordbruket! I nuläget använder vi redan perenner i våra vallar och betesmarker, men kanske kan perenn stråsäd, t ex Kernza, utgöra ett väsentligt bidrag eftersom den har visat sig ha många miljömässiga fördelar jämfört med till exempel ettårigt vete. Förra året etablerades den första bruksodlingen av Kernza i Europa, i Högestad utanför Ystad.
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| 24. |
- Dimitrova Mårtensson, Linda-Maria, et al.
(författare)
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Water use efficiency and shoot biomass production under water limitation is negatively correlated to the discrimination against 13C in the C3 grasses Dactylis glomerata, Festuca arundinacea and Phalaris arundinacea
- 2017
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Ingår i: Plant Physiology and Biochemistry. - : Elsevier BV. - 0981-9428 .- 1873-2690. ; 113, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Climate change impacts rainfall patterns which may lead to drought stress in rain-fed agricultural systems. Crops with higher drought tolerance are required on marginal land with low precipitation or on soils with low water retention used for biomass production. It is essential to obtain plant breeding tools, which can identify genotypes with improved drought tolerance and water use efficiency (WOE). In C-3 plant species, the variation in discrimination against C-13(Delta,13C) during photosynthesis has been shown to be a potential indicator for WOE, where discrimination against C-13 and WUE were negatively correlated. The aim of this study was to determine the variation in the discrimination against C-13 between species and cultivars of three perennial C-3 grasses (Dactylis glomerate (cocksfoot), Festuca arundinacea (tall fescue) and Phalaris arundinacea (reed canary grass)) and test the relationships between discrimination against C-13, season-long water use WUEB, shoot and root biomass production in plants grown under well-watered and water-limited conditions. The grasses were grown in the greenhouse and exposed to two irrigation regimes, which corresponded to 25% and 60% water holding capacity, respectively. We found negative relationships between discrimination against C-13 and WUEB and between discrimination against C-13 and shoot biomass production, under both the well-watered and water-limited growth conditions (p < 0.001). Discrimination against C-13 decreased in response to water limitation (p < 0.001). We found interspecific differences in the discrimination against C-13, WUEB, and shoot biomass production, where the cocksfoot cultivars showed lowest and the reed canary grass cultivars highest values of discrimination against C-13. Cocksfoot cultivars also showed highest WUEB, shoot biomass production and potential tolerance to water limitation. We conclude that discrimination against C-13 appears to be a useful indicator, when selecting C-3 grass crops for biomass production under drought conditions. (C) 2017 Elsevier Masson SAS. All rights reserved.
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| 25. |
- Ekelöf, Joakim, et al.
(författare)
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Inter-Row Subsoiling and Irrigation Increase Starch Potato Yield, Phosphorus Use Efficiency and Quality Parameters
- 2015
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Ingår i: Potato Research. - : Springer Science and Business Media LLC. - 0014-3065 .- 1871-4528. ; 58, s. 15-27
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Tidskriftsartikel (refereegranskat)abstract
- Soil compaction due to the intensive use of heavy machinery is often a problem in potato production. Compaction can limit vertical root growth, water and nutrient uptake, and air and water infiltration, resulting in substantial yield reductions. This study examined the effects of inter-row subsoiling and irrigation on potato yield, tuber quality and phosphorus use efficiency (PUE) in three experiments in southern Sweden on soils with a documented plough pan at 25-30 cm. Potato (Solanum tuberosum L.) was grown in plots treated with inter-row subsoiling to a depth of 55 cm post planting, but prior to the start of root development, or in non-subsoiled plots. In addition, the interaction between inter-row subsoiling and irrigation was investigated under three different irrigation strategies: control (non-irrigated), intensive irrigation and moderate irrigation. Inter-row subsoiling significantly increased average starch yield, phosphorus use efficiency and total uptake of phosphorus in the three experiments. Irrigation significantly increased starch yield and tuber quality. Potato quality was significantly improved by a decrease in the incidence of common scab in the intensive irrigation regime, but the incidence of green tubers increased in the subsoiled plots. No significant interaction between tillage treatment and irrigation strategy was observed.
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| 26. |
- Ekelöf, Joakim, et al.
(författare)
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Potato yield response to foliar application of phosphorus as affected by soil moisture and available soil phosphorus
- 2012
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Ingår i: Acta Agriculturae Scandinavica, Section B - Soil and Plant Science. - : Informa UK Limited. - 0906-4710 .- 1651-1913. ; 62, s. 637-643
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Tidskriftsartikel (refereegranskat)abstract
- Foliar application of phosphorus (P) may be a supplementary treatment to sustain adequate P-status of potato (Solanum tuberosum L.). However, the prediction of the potential benefits of foliar P supply is difficult, since several factors, such as weather conditions and plant P-status influence the effects. We determined the impact of soil moisture and soil P-supply on the responsiveness to foliar P-application under controlled environmental conditions. Plant dry matter yields, P-accumulation and phosphorus use efficiency (PUE) with or without foliar application were determined at five soil P-levels in combination with two soil moisture levels. The results suggest that water status is of importance for the responsiveness to foliar P-application and may be related to diffusion of P through the leaf cells, which require a good water status. The PUE was significantly improved with irrigation while adding P to the soil decreased the PUE.
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| 27. |
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| 28. |
- Ernfors, Maria, et al.
(författare)
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Effects of crop residue vertical distribution, temperature, moisture and freeze-thaw on N2O/CO2 emissions
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Three main incubation studies were conducted to identify how management, residue properties and soil properties, alone or in interaction, affect N2O emissions. The aim was to contribute to improving both inventories and mitigation strategies. Treatments used in various combinations were: residue type, vertical residue distribution, fertilization, soil moisture, soil type and freezing/thawing. The results showed clearly that several factors interact to determine the magnitude of N2O emissions after addition of residues to soil. We conclude that inventories should ideally integrate other factors than the total amount of N added with the residues and also take into account the effects of combinations of factors. Although the mechanisms behind N2O emissions are complex, the results pointed to combinations of residue type, management, soil type and season that create particularly high risks of N2O emissions, and field situations representing such combinations could be targeted for mitigation.
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| 29. |
- Ernfors, Maria, et al.
(författare)
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Effects of the quality, amount and spatial distribution of arable and ley crop residues on field N2O emissions
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We present results from a 2-year field study in southern Sweden, on annually cropped fields, and two 1-year field studies in southern Norway, on temporary grassland. Gas fluxes were measured over the winter season, from early or mid-autumn to late spring. Residues of different qualities (ley with clover, ley without clover, winter wheat and sugar beet) were studied in combinations with management options (aboveground residues removed, retained or doubled). In selected treatments, the effects of an increase in pH were investigated. The outcomes of the studies imply that sugar beet residues, ley herbage containing red clover, and possibly other “immature” residues, produce higher N2O emissions at higher residue application rates - their removal could therefore be considered as a mitigation option, although the effect may not always be large. For wheat residues, and likely also other “mature” residues, the results indicate that removing residues may increase N2O emissions, although inconsistencies and effects well beyond the initial few months call for further study. It is clear from our results that residue quality strongly affects N2O emission patterns and should not be neglected. Our results add to previous evidence that moderately cold winter conditions with frozen soil at ~0°C can elicit strong N2O production, if there is sufficient substrate for heterotrophic respiration, as in the case of temporary grassland renewal. The slightly warmer conditions, with very little snow cover, in the Swedish study, provided a contrast with relatively low winter emissions. Based on the low emission factors for ley roots observed, and the difficulties in distinguishing background from root emissions and estimating amounts of root N, one may consider an alternative approach to the current IPCC methodology, not assigning any specific emission to roots, but instead include them in an estimate of background emissions. We could demonstrate that liming a low-pH soil can be an effective N2O emission mitigation tool, even when the nitrogen source is primarily organic and nitrification is an essential step prior to denitrification.
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| 30. |
- Hydbom, Sofia, et al.
(författare)
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Reduced tillage stimulated symbiotic fungi and microbial saprotrophs, but did not lead to a shift in the saprotrophic microorganism community structure
- 2017
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 119, s. 104-114
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Tidskriftsartikel (refereegranskat)abstract
- The need for sustainable agricultural systems, which for example enhance soil organic carbon (SOC) content, has increased the interest for management with reduced tillage. In this study we used a Swedish long-term (20 yrs.) systems experiment, including reduced tillage (harrowing 10 cm) and plowing (moldboard plow 0–20 cm) combined with three levels of nitrogen (N) fertilization. With this setup we tested if (1) the arbuscular mycorrhizal fungi (AMF) concentration and (2) the fungi to bacteria (F:B) ratio would be higher under reduced tillage than under conventional tillage, and if this would be associated with higher SOC concentrations. We also tested if (3) the microbial biomass C close to the surface would be higher under reduced tillage than conventional tillage. Furthermore, since disturbance can reduce respiration and microbial growth we tested if (4) this occurred in our reduced tillage system. In addition, we tested if (5) fertilization increased the growth rate of fungi and decreased that of bacteria. We collected soil samples in July and October and found that the microbial biomass C, measured in October only, was higher close to the surface in the reduced tillage treatment and so was the microbial respiration. The fungal and bacterial growth rate, on the other hand, were not affected by tillage treatment. Fertilization did not affect the bacterial growth rate but did have a positive effect on fungal growth rate. In accordance with our expectations reduced tillage had a stimulating effect on AMF and saprotrophic fungi, and contrary to our expectation, also bacteria were positively affected by reduced tillage. In line with the unchanged F:B ratio, we found no indication that even 20 years of reduced tillage increased SOC concentrations in the long term.
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| 31. |
- Jensen, Erik Steen
(författare)
-
Agroecologist Education for Sustainable Development of Farming and Food Systems
- 2017
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Ingår i: Agronomy Journal. - : Wiley. - 0002-1962 .- 1435-0645. ; 109, s. 23-32
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Tidskriftsartikel (refereegranskat)abstract
- Twelve educational strategies for future agroecologists are based on experiences in Nordic universities, with priorities informed by six propositions about future resource challenges. The principal objective is student learning for future challenges and contributions to sustainable development of farming and food systems, including practice in acquiring capacities needed for responsible future action. The heart of the program is learning to apply ecological principles in design of farming and food systems, using multi-criteria evaluation for prioritizing sustainability challenges, and measuring exante success of transition. Working closely with farming and food system stakeholders in design and implementation of learning environment is essential, plus recognizing contributions of farmers and food system professionals as vital to education for design of future systems. Holistic approaches integrate multiple disciplines, and combine technologies developed through science with those discovered in the field. Students' prior experiences also contribute to activities in the learning landscape, and important skills are developed for autonomous and lifelong learning. Practices from organic farming and other alternative farming strategies provide useful examples, and local food systems represent one viable option that can potentially reduce food distance and food waste, and thus contribute to food security and food sovereignty. Capacities to deal with difficult challenges are developed by each student in agroecology and related courses, including observation, participation, reflection, dialogue, and visioning. These capacities are applied while completing a thesis project using natural science and social science methods that affirm their skills and prepare students well for responsible action in a complex and uncertain future.
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| 32. |
- Jensen, Erik Steen
(författare)
-
Annual maize and perennial grass-clover strip cropping for increased resource use efficiency and productivity using organic farming practice as a model
- 2013
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Ingår i: European Journal of Agronomy. - : Elsevier BV. - 1161-0301 .- 1873-7331. ; 47, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- A cropping system was designed to fulfill the increasing demand for biomass for food and energy without decreasing long term soil fertility. Afield experiment was carried out including alternating strips of annual maize (Zea mays L.) and perennial ryegrass (Lolium perenne L.) - clover (Trifolium repens + Trifolium pretense L.) mixture grown in the same field. In autumn an annual strip was established with green-rye (Secale cereale L.) after soil incorporation of a 1st year grass-clover a 6-m wide strip followed by maize sowing in May. The perennial strips were established without incorporating the same 1st year grass-clover in an equivalent 6-m wide strip, resulting in an early competitive advantage for the perennial strip toward the annual strip. Throughout the growing season maize was never able to recovery from this and yields were reduced with around 50% when grown adjacent to grass-clover (0-50 cm) compared to with >50 cm distance. There was significantly greater clover content in the sward when grown with >150 cm distance to maize (30%) compared to the 0-25 cm distance (10%) indicating more available soil mineral N in the interface between the strips related to a strong ability of the grass to compete for soil mineral N. Maize yields were clearly associated with N fertilizer application. When fertilizer N was applied through slurry or anaerobic digested slurry maize yields was increasing with up to 100% equivalent to 1200 g carbon (C) m(-2) or 35 MJ m(-2). However, the same relative growth reduction was found when grown in close proximity to the grass-clover strip. If slurry is available maize secures an efficient N uptake, however, long-term effects of maize cropping and biomass removal on soil quality is of concern. The present strip cropping system did not possess the right balance of co-existence and complementarity with relative yield advantages for the whole crop cycle between 0.96 and 1.01. Thus, the total land area required under traditional cropping attaining the yields achieved when dividing the field in strips is the same. Greater complementarity between strips is needed to gain the potential strip cropping advantages. (C) 2013 Elsevier B.V. All rights reserved.
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| 33. |
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| 34. |
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| 35. |
- Jensen, Erik Steen, et al.
(författare)
-
Biomass production and water use efficiency in perennial grasses during and after drought stress
- 2018
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 10, s. 12-27
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Tidskriftsartikel (refereegranskat)abstract
- Drought is a great challenge to agricultural production, and cultivation of drought-tolerant or water use-efficient cultivars is important to ensure high biomass yields for bio-refining and bioenergy. Here, we evaluated drought tolerance of four C-3 species, Dactylis glomerata cvs. Sevenop and Amba, Festuca arundinacea cvs. Jordane and Kora, Phalaris arundinacea cvs. Bamse and Chieftain and Festulolium pabulare cv. Hykor, and two C-4 species Miscanthusxgiganteus and M.lutarioriparius. Control (irrigated) and drought-treated plants were grown on coarse and loamy sand in 1 m(2) lysimeter plots where rain was excluded. Drought periods started after harvest and lasted until 80% of available soil water had been used. Drought caused a decrease in dry matter yield (DM; P<0.001) for all species and cultivars during the drought period. Cultivars Sevenop, Kora and Jordane produced DM at equal levels and higher than the other C-3 cultivars in control and drought-treated plots both during and after the drought period. Negative correlations were observed between stomatal conductance (g(s)) and leaf water potential (P<0.01) and positive correlations between g(s) and DM (P<0.05) indicating that g(s) might be suitable for assessment of drought stress. There were indications of positive associations between plants carbon isotope composition and water use efficiency (WUE) as well as DM under well-watered conditions. Compared to control, drought-treated plots showed increased growth in the period after drought stress. Thus, the drought events did not affect total biomass production (DMtotal) of the whole growing season. During drought stress and the whole growing season, WUE was higher in drought-treated compared to control plots, so it seems possible to save water without loss of biomass. Across soil types, M.lutarioriparius had the highest DMtotal (15.0tha(-1)), WUEtotal (3.6gL(-1)) and radiation use efficiency (2.3gMJ(-1)) of the evaluated grasses.
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| 36. |
- Jensen, Erik Steen
(författare)
-
Challenges for Sustainable Development
- 2010
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Ingår i: The Biobased Economy - Biofuels, Materials and Chemicals in The Post-Oil Era. - 9781844077700 ; , s. 33-48
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 37. |
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| 38. |
- Jensen, Erik Steen, et al.
(författare)
-
Design, assessment and feasibility of legume-based cropping systems in three European regions
- 2017
-
Ingår i: Crop & Pasture Science. - 1836-0947 .- 1836-5795. ; 68, s. 902-914
-
Tidskriftsartikel (refereegranskat)abstract
- Grain legumes in cropping systems result in agronomic and environmental benefits. Nevertheless, their areas in Europe have strongly decreased over the past decades. Our aim was to design locally adapted innovative cropping systems including grain legumes for three European local pedoclimatic contexts, to assess their sustainability, and to discuss their feasibility with stakeholders. The methodology included an initial diagnosis of the most frequent cropping systems and local improvement targets in each local context (e.g. improve legume profitability, limit diseases of legumes, reduce intensive use of chemical inputs in cropping systems), the design of innovative legume-based cropping systems during a common workshop, focusing on three aims ((i) decrease pesticide use, (ii) reduce mineral N fertiliser dependency, and (iii) increase yield stability of grain legume crops and other crops of the crop sequence), and their multicriteria sustainability assessment. Stakeholders meetings were organised in each local context to discuss the feasibility of implementing the innovative cropping systems in farmers’ fields (technical implementation of cropping systems and possibility of development of legume sectors). Four to five cropping systems were designed in each local context, with crop sequences longer than references. They included at least two grain legumes (pea, faba bean, chickpea, lentil or lupine), as sole crops or intercropped with cereals. Overall sustainability was similar or improved in 71% of the legume-based cropping systems compared with their corresponding references. Among the designed cropping systems, stakeholders identified feasible ones considering both technical issues and development of legume sectors. The results indicate that reintegrating more grain legumes in the three European local contexts tested will contribute to more sustainable farming systems.
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| 39. |
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| 40. |
- Jensen, Erik Steen
(författare)
-
Designing intercrops for high yield, yield stability and efficient use of resources: are there principles?
- 2020
-
Ingår i: Advances in Agronomy. - : Elsevier. - 0065-2113 .- 2213-6789. ; 160, s. 1-50
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Forskningsöversikt (refereegranskat)abstract
- Intercropping is the simultaneous cultivation of plant species in the same field for a considerable proportion of their growing periods. Interest in intercropping for sustainable agriculture is on the rise and the number of scientific studies on intercropping is strongly increasing. Here we assess the current status of knowledge on factors that determine yield, yield stability and resource use efficiency of intercropping as compared to sole cropping. Distinguishing resource use into acquisition and conversion shows that intercrops are mainly improving acquisition rather than conversion efficiency. We also make an attempt to quantify the importance of reduced biotic stresses through pests, diseases, and weeds. We particularly focus on blank spots in the knowledge and possible bias in existing literature and ask which research approaches are needed to advance the field and pave the way for a wider usage of intercropping in modern sustainable agriculture.
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| 41. |
- Jensen, Erik Steen, et al.
(författare)
-
Diversifying European agricultural systems by intercropping grain legumes and cereals
- 2020
-
Ingår i: INTERNATIONAL JOURNAL OF AGRICULTURE AND NATURAL RESOURCES. - : PONTIFICIA UNIV CATOLICA CHILE. - 2452-5731. ; 47:3
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Tidskriftsartikel (refereegranskat)abstract
- E.S. Jensen, I.R. Chongtham, N.R. Dhamala, C. Rodriguez, N. Carton, and G. Carlsson.2020. Diversifying European agricultural systems by intercropping grain legumesand cereals. Int. J. Agric. Nat. Resour. 174-186. Cropping system diversification is akey factor in developing more sustainable cropping and food systems. The agroecologicalpractice of intercropping, meaning the simultaneous cultivation of two or more species inthe same field, has recently gained renewed interest as a means of ecological intensificationin European agricultural research. We discuss some recent research developments regarding1) intercropping for ecological intensification in agroecological and conventional croppingsystems, 2) studies on nitrogen resource use by cereal-grain legume intercropping cultivation,3) the role of intercropping in the management of biotic stressors, especially weeds, and 4)intercropping as a means of creating cropping systems that are more resilient to the abioticand biotic stress associated with climate change. Finally, we propose methods for the greateradoption of intercropping in European agriculture by unlocking farming systems from upstreamand downstream barriers, with the aim of developing more sustainable agricultural and foodsystems.
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| 42. |
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| 43. |
- Jensen, Erik Steen
(författare)
-
Ecological principles underlying the increase of productivity achieved by cereal-grain legume intercrops in organic farming. A review
- 2015
-
Ingår i: Agronomy for Sustainable Development. - : Springer Science and Business Media LLC. - 1774-0746 .- 1773-0155. ; 35, s. 911-935
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Forskningsöversikt (refereegranskat)abstract
- World population is projected to reach over nine billion by the year 2050, and ensuring food security while mitigating environmental impacts represents a major agricultural challenge. Thus, higher productivity must be reached through sustainable production by taking into account climate change, resources rarefaction like phosphorus and water, and losses of fertile lands. Enhancing crop diversity is increasingly recognized as a crucial lever for sustainable agro-ecological development. Growing legumes, a major biological nitrogen source, is also a powerful option to reduce synthetic nitrogen fertilizers use and associated fossil energy consumption. Organic farming, which does not allow the use of chemical, is also regarded as one prototype to enhance the sustainability of modern agriculture while decreasing environmental impacts. Here, we review the potential advantages of eco-functional intensification in organic farming by intercropping cereal and grain legume species sown and harvested together. Our review is based on a literature analysis reinforced with integration of an original dataset of 58 field experiments conducted since 2001 in contrasted pedo-climatic European conditions in order to generalize the findings and draw up common guidelines. The major points are that intercropping lead to: (i) higher and more stable grain yield than the mean sole crops (0.33 versus 0.27 kg m(-2)), (ii) higher cereal protein concentration than in sole crop (11.1 versus 9.8 %), (iii) higher and more stable gross margin than the mean sole crops (702 versus 577 a,not signaEuro parts per thousand ha(-1)) and (iv) improved use of abiotic resources according to species complementarities for light interception and use of both soil mineral nitrogen and atmospheric N-2. Intercropping is particularly suited for low-nitrogen availability systems but further mechanistic understanding is required to propose generic crop management procedures. Also, development of this practice must be achieved with the collaboration of value chain actors such as breeders to select cultivars suited to intercropping.
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| 44. |
- Jensen, Erik Steen
(författare)
-
Effects of digestate from anaerobically digested cattle slurry and plant materials on soil microbial community and emission of CO2 and N2O
- 2013
-
Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 63, s. 36-44
-
Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion of animal manure and crop residues may be employed to produce biogas as a climate-neutral source of energy and to recycle plant nutrients as fertilizers. However, especially organic farmers are concerned that fertilizing with the digestates may impact the soil microbiota and fertility because they contain more mineral nitrogen (N) and less organic carbon (C) than the non-digested input materials (e.g. raw animal slurry or fresh plant residues). Hence, an incubation study was performed where (1) water, (2) raw cattle slurry, (3) anaerobically digested cattle slurry/maize, (4) anaerobically digested cattle slurry/grass-clover, or (5) fresh grass-clover was applied to soil at arable realistic rates. Experimental unites were sequentially sampled destructively after 1, 3 and 9 days of incubation and the soil assayed for content of mineral N, available organic C, emission of CO2 and N2O, microbial phospholipid fatty acids (biomass and community composition) and catabolic response profiling (fiinctional diversity). Fertilizing with the anaerobically digested materials increased the soil concentration of NO3- ca. 30-40% compared to when raw cattle slurry was applied. Grass-clover contributed with four times more readily degradable organic C than the other materials, causing an increased microbial biomass which depleted the soil for mineral N and probably also O-2. Consequently, grass-clover also caused a 10 times increase in emissions of CO2 and N2O greenhouse gasses compared to any of the other treatments during the 9 days. Regarding microbial community composition, grass-clover induced the largest changes in microbial diversity measures compared to the controls, where raw cattle slurry and the two anaerobically digested materials (cattle slurry/maize, cattle slurry/grass-clover) only induced minor and transient changes. (C) 2012 Elsevier B.V. All rights reserved.
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| 45. |
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| 46. |
- Jensen, Erik Steen, et al.
(författare)
-
Enhancing Yields in Organic Crop Production by Eco-Functional Intensification
- 2015
-
Ingår i: Sustainable Agriculture Research. - : Canadian Center of Science and Education. - 1927-050X .- 1927-0518. ; 4, s. 42-50
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Tidskriftsartikel (refereegranskat)abstract
- Organic agriculture faces challenges to enhance food production per unit area and simultaneously reduce the environmental and climate impacts, e.g. nitrate leaching per unit area and greenhouse gas (GHG) emissions per unit mass produced. Eco-functional intensification is suggested as a means to reach these objectives. Eco-functional intensification involves activating more knowledge and refocusing the importance of ecosystem services in agriculture. Organic farmers manage agrobiodiversity by crop rotation (diversification in time). However, sole cropping (SC) of genetically identical plants in organic agriculture may limit resource use efficiency and yield per unit area. Intercropping (IC) of annual grain species, cultivar mixes, perennial grains, or forage species and forestry and annual crops (agroforestry) are examples of spatial crop diversification. Intercropping is based on eco-functional intensification and may enhance production by complementarity in resource use in time and space. Intercropping is based on the ecological principles of competition, facilitation and complementarity, which often increases the efficiency in acquisition and use of resources such as light, water and nutrients compared to sole crops, especially in low-input systems. Here we show that IC of cereals and grain legumes in European arable organic farming systems is an efficient tool for enhancing total grain yields compared to their respective sole crops. Simultaneously, we display how intercropping of cereals and legumes can be used as an efficient tool for weed management and to enhance product quality (i.e. cereal grain protein concentration). We discuss how intercropping contributes to efficient use of soil N sources and minimizes losses of N by nitrate leaching via Ecological Precision Farming. It is concluded that intercropping has a strong potential to increase yield and hereby reduce global climate impacts such as GHG kg-1 grain. Finally, we discuss likely barriers and lock-in effects for increased use of intercropping in organic farming and suggest a roadmap for innovation and implementation of IC strategies in organic agriculture.
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| 47. |
- Jensen, Erik Steen
(författare)
-
Europe: Cereal and legume intercropping.
- 2015
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Ingår i: Replacing Chemicals with Biology: Phasing out highly hazardous pesticides with agroecology. - 9789839381702 ; , s. 162-167
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Bokkapitel (populärvet., debatt m.m.)
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| 48. |
- Jensen, Erik Steen
(författare)
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Faba bean in cropping systems
- 2010
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Ingår i: Field Crops Research. - : Elsevier BV. - 0378-4290 .- 1872-6852. ; 115, s. 203-216
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Forskningsöversikt (refereegranskat)
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| 49. |
- Jensen, Erik Steen
(författare)
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Faba bean in cropping systems
- 2011
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Ingår i: Grain Legumes. - 1245-4710. ; , s. 32-33
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 50. |
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