Change search
Refine search result
1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Enfors, Elin
    et al.
    Stockholm University, Faculty of Science, Department of Systems Ecology. Stockholm University, Stockholm Resilience Centre.
    Barron, Jennie
    Stockholm University, Stockholm Resilience Centre, Stockholm Environment Institute.
    Makurira, Hodson
    University of Zimbabwe.
    Rockström, Johan
    Stockholm University, Stockholm Resilience Centre, Stockholm Environment Institute.
    Tumbo, Siza
    Sokoine University of Agriuclture.
    Yield and soil system changes from conservation tillage in dryland farming: A case study from North Eastern Tanzania2011In: Agricultural Water Management, ISSN 0378-3774, E-ISSN 1873-2283, Vol. 98, no 11, p. 1687-1695Article in journal (Refereed)
    Abstract [en]

    Yield levels in smallholder farming systems in semi-arid sub-Saharan Africa are generally low. Water shortage in the root zone during critical crop development stages is a fundamental constraining factor. While there is ample evidence to show that conservation tillage can promote soil health, it has recently been suggested that the main benefit in semi-arid farming systems may in fact be an in situ water harvesting effect. In this paper we present the result from an on-farm conservation tillage experiment (combining ripping with mulch and manure application) that was carried out in northeastern Tanzania from 2005 to 2008, testing this hypothesis. Special attention was given to the effects on the water retention properties of the soil. The tested conservation treatment only had a clear yield increasing effect during one of the six experimental seasons (maize grain yields increased by 41%, and biomass by 65%), and this was a season that received exceptional amounts of rainfall (549 mm). While the other seasons provided mixed results, there seemed to be an increasing yield gap between the conservation tillage treatment and the control towards the end of the experiment. Regarding soil system changes, small but significant effects on chemical and microbiological properties, but not on physical properties, were observed. This raises questions about the suggested water harvesting effect and its potential to contribute to stabilized yield levels under semi-arid conditions. We conclude that, at least in a shorter time perspective, the tested type of conservation tillage seems to boost productivity during already good seasons, rather than stabilize harvests during poor rainfall seasons. Highlighting the challenges involved in upgrading these farming systems, we discuss the potential contribution of conservation tillage towards improved water availability in the crop root zone in a longer-term perspective.

  • 2. Gharasoo, Mehdi
    et al.
    Centler, Florian
    Fetzer, Ingo
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. UFZ Helmholtz Center for Environmental Research, Germany.
    Thullner, Martin
    How the chemotactic characteristics of bacteria can determine their population patterns2014In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 69, p. 346-358Article in journal (Refereed)
    Abstract [en]

    Spatial distribution of soil microorganisms is relevant for the functioning and performance of many ecosystem processes such as nutrient cycling or biodegradation of organic matters and contaminants. Beside the multitude of abiotic environmental factors controlling the distribution of microorganisms in soil systems, many microbial species exhibit chemotactic behavior by directing their movement along concentration gradients of nutrients or of chemoattractants produced by cells of their own kind. This chemotactic ability has been shown to promote the formation of complex distribution patterns even in the absence of environmental heterogeneities. Microbial population patterns in heterogeneous soil systems might be, hence, the result of the interplay between the heterogeneous environmental conditions and the microorganisms' intrinsic pattern formation capabilities. In this modeling study, we combined an individual-based modeling approach with a reactive pore-network model to investigate the formation of bacterial patterns in homogeneous and heterogeneous porous media. We investigated the influence of different bacterial chemotactic sensitivities (toward both substrate and bacteria) on bacterial distribution patterns. The emerging population patterns were classified with the support of a geostatistical approach, and the required conditions for the formation of any specific pattern were analyzed. Results showed that the chemotactic behavior of the bacteria leads to non-trivial population patterns even in the absence of environmental heterogeneities. The presence of structural pore scale heterogeneities had also an impact on bacterial distributions. For a range of chemotactic sensitivities, microorganisms tend to migrate preferably from larger pores toward smaller pores and the resulting distribution patterns thus resembled the heterogeneity of the pore space. The results clearly indicated that in a porous medium like soil the distribution of bacteria may not only be related to the external constraints but also to the chemotactic behavior of the bacterial cells.

  • 3.
    Hjulström, Björn
    et al.
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies. Arkeologiska Forskningslaboratoriet.
    Isaksson, Sven
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies. Arkeologiska Forskningslaboratoriet.
    Dolda spår av forntida verksamhet2007In: Hus och bebyggelse i Uppland: Delar av förhistoriska sammanhang, 2007Chapter in book (Other academic)
  • 4.
    Ihse, Margareta
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology. ekologisk geografi.
    Från våtmark till våtmark: - ett akademiföretal2008In: Svensk Mosskultur: odling, torvanvändning, och landskapets förändring, Svenska Skogs- och Lantbruksakademien, Stockholm , 2008Chapter in book (Other academic)
    Abstract [sv]

    Framför dig har du intressant bok om en alldeles speciell epok i Sveriges odlingshistoria, uppodlingen av myrarna för drygt hundra år sedan och framväxten av en hel agrar kultur, mossekulturen. Som akademiledamot och naturgeograf med intresse för landskapets ekologiska historia finner jag denna bok högst angelägen. Boken ger inte bara en solid kunskap om mossodlingen och torvanvändningen. Den ger också en utmärkt förståelse för tidigare agrarers arbete med att säkra matförsörjningen, i en tid när befolkningen snabbt ökade och man hade stort sett utnyttjat alla kända tillgängliga marker för livsmedelsproduktion. Boken är av ett stort allmänt intresse, inte bara för de akademiledamöter som har agrar bakgrund utan också för forskare och handläggare och för en intresserad allmänhet. Den ger framförallt genom sitt breda innehåll en beskrivning av ett historiskt landskapsutnyttjande och landskapsförändring på ett tema som skulle kunna beskrivas med ett modernare begrepp ”från våtmark till våtmark”. Här visas hur ändrad kunskap och ändrade behov gett upphov till förändrat nyttjande av torvmarkernas olika ekosystemtjänster, från livsmedelsproducent till koldioxidfångare, vattenreglerare och biodiversitetsbevarare.

  • 5.
    Seibert, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Stendahl, Johan
    Sørensen, Rasmus
    Topographical influences on soil properties in boreal forests2007In: Geoderma, Vol. 141, no 1-2, p. 139-148Article in journal (Refereed)
1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf