| 1. |
- Lagerlöf, Jan, et al.
(författare)
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Potential side effects of biocontrol and plant-growth promoting Bacillus amyloliquefaciens bacteria on earthworms
- 2015
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393 .- 1873-0272. ; 96, s. 159-164
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Tidskriftsartikel (refereegranskat)abstract
- After 1-2 months, survival, growth and reproduction of the earthworms were recorded. We found no effect of the treatments as compared to control without BA amendments. We conclude that the use of high doses of BA with concentrations at the same magnitude as maximally expected when the bacteria are used as PGPR and BCA, is not harmful to the soil dwelling earthworms tested in this project. Further studies of the ecological effects of PGPR and BCA bacteria on other non-target soil organisms are encouraged. The development of sustainable agricultural systems, where ecosystem services are optimized, has to be aided by a deeper knowledge of the combined effect of bacteria and earthworms on the promotion of plant health. (C) 2015 Elsevier B.V. All rights reserved.
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| 2. |
- Lagerquist, Elsa, et al.
(författare)
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Assessing the effect of intercropped leguminous service crops on main crops and soil processes using APSIM NG
- 2024
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Ingår i: Agricultural Systems. - 0308-521X .- 1873-2267. ; 216
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: To improve agricultural sustainability, alternative cultivation methods and assessment tools need to be developed. Integrating service crops (SC) can potentially increase cropping system multifunctionality and mitigate negative climate and environmental impacts of agriculture. OBJECTIVES: (1) Calibrate oats, winter wheat and red clover SC, grown as sole crops and intercrops, in the cropping system model APSIM NG for northern Europe climate conditions. (2) Use the calibrated crop modules to assess ecosystem processes from an intercropping system. (3) Discuss the role of mechanistic crop models in assessing ecosystem services and disservices from complex cropping systems. METHODS: The crops were calibrated with data from an oats-winter wheat cropping sequence at two field sites. Thirty weather datasets were created from historical weather data to generate weather-dependent variability in crop performance and related processes. The assessment compared two scenarios, with or without an intercropped red clover SC sown in oats and terminated the following spring in winter wheat. Outputs representing processes related to important ecosystem services were extracted from the simulations. RESULTS , CONCLUSIONS: Calibration of the three crops resulted in satisfactory biomass levels at the end of the growing season. Including a SC reduced oat yield, but increased winter wheat yield in two-thirds of simu- lations. Model outputs showed that including a SC resulted in 33-79% more fresh soil organic carbon, depending on site, compared with no SC. Nitrogen (N) uptake by both crops was highest in the SC scenario. In oats, N losses did not differ between the two scenarios, while in winter wheat the SC scenario had approximately 50% lower N leaching losses , 30% higher gaseous N emissions. However, in the fallow period from winter wheat harvest through to spring, both types of N losses were elevated in the SC scenario. The SC scenario had only a minor effect on water dynamics, causing a small reduction in soil water content. SIGNIFICANCE: In this paper we give an example of how APSIM NG can be used to assess ecosystem services from complex agricultural systems using a case study with intercropping of cereals and leguminous SCs. APSIM NG was useful in providing a holistic assessment , we show that intercropping with a SC can improve cropping system performance and reduce negative impacts, but long-term strategic management of N is required to prevent increased losses. To further improve simulation of intercrops more accurate simulation of early growth is needed for all crops included.
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| 3. |
- Lagerquist, Elsa
(författare)
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Leguminous service crops in cereal production at high latitudes : provision of ecosystem services and disservices from a novel intercropping system
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Service crops, crops grown to provide services such as soil protection, weed control, or nutrient capture and provision, can reduce the need for mineral fertilisers and intensive weed control. However, high biomass production is necessary in order for these services to be provided. This can be difficult to achieve at high latitudes (e.g. Sweden), where growing conditions are poor after main crop harvest, when service crops are usually sown. The aim of this thesis was to increase the understanding of service crop species choice and management on service and disservice delivery. Leguminous service crops were sown into oats in spring/early summer for early establishment of the service crop, and terminated in the following spring in winter wheat. The results showed that species sown at the same time as oats, rather than one month later, and which survived oat harvest and cold temperatures in winter, were best at suppressing weeds and increasing winter wheat yields, although they often also reduced oat yield in the establishment year. Presence of a productive service crop (>0.2 t dry weight (DW) per ha) reduced the occurrence of competitive-stress tolerant weed species, in favour of ruderal species, in the oat row and in combination with oat biomass >8 t DW ha-1 the occurrence of competitive perennial species was reduced. Modelling the system using APSIM NG revealed that the service crops mainly provided positive effects on the cropping system, in terms of increased winter wheat yield, increased soil carbon input and reduced losses of nitrogen and water during most of the study period. Drawbacks were reduced oat yield and increased nitrogen losses from winter wheat and in the fallow period after winter wheat. I conclude that the studied intercropping system has potential to provide services and reduce disservices, but that the system needs improvement. These improvements are mainly to ensure even establishment and good termination of the service crops.
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| 4. |
- Lagerquist, Elsa, et al.
(författare)
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Temporal and Spatial Positioning of Service Crops in Cereals Affects Yield and Weed Control
- 2022
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Ingår i: Agriculture. - : MDPI AG. - 2077-0472. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Leguminous service crops (SCs) can provide multiple services to cropping systems, reducing the reliance on external resources if sufficient biomass is produced. However, rapid light and temperature reductions limit post-harvest cultivation of SCs in Northern Europe. A novel practice of intercropping SCs in two consecutive crops (spring-winter cereal) to extend the period of SCs growth, and hence improve yield and reduce weeds, was tested. Three spatial and temporal arrangements of SCs and cash crops were investigated, as well as three SC mixtures, characterized by their longevity and frost sensitivity. Compared to no SC, the best performing mixture, frost-tolerant annuals, increased grain and N yield of winter wheat by 10% and 19%, respectively, and reduced weed biomass by 15% and 26% in oats and winter wheat, respectively. These effects were attributed to high biomass production and winter survival. However, this SC reduced oat yields by 15% compared to no SC. Furthermore, SC growth and service provision varied largely between experiments, driven by the weather conditions. Extending the SC's growth period by intercropping in two consecutive cereal crops has potential, but locally adapted species choices and establishment strategies are needed to ensure SC vitality until termination.
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