• Authors:
    • Soinne,Helena
    • Hovi,Jarkko
    • Tammeorg,Priit
    • Turtola,Eila
  • Source: Geoderma
  • Volume: 219
  • Year: 2014
  • Summary: Soil structure is one of the key properties affecting the productivity of soils and the environmental side effects of agricultural soils. Poor surface soil structure increases the risk of soil erosion by water and eroded clay-sized particles can carry adsorbed phosphorus (P) to the surface waters, thus inducing eutrophication of receiving waterways. Management practices, e.g. reduced tillage, used to reduce erosion can lead to enrichment of P in the uppermost soil layers, which leads to elevated risk for dissolved P loss in the runoff water. In this study, we aimed to identify whether biochar (BC) could be used to reduce clay soil erosion by improving aggregate stability. Moreover, we tested whether the BC addition would change the P sorption affinity of the soil and help to reduce the loss of dissolved P. One sandy and two clayey soils were amended with BC (0,15 and 30 t ha(-1)) and after a 3week incubation, a wet-sieving method was used to measure the release of colloidal particles and the stability of aggregates. The sorption of P onto soil surfaces was estimated with a Q/I (quantity/intensity) plot technique. The BC used here had a very low P sorption affinity and the BC addition did not increase the sorption of P in incubated soils. However, for the two clayey soils, the BC additions increased aggregate stability and reduced detachment of colloidal material. The BC thus induced changes in soil properties that could be beneficial for erosion control and thereby aid in reducing particulate P losses from agricultural fields. (c) 2014 Elsevier B.V. All rights reserved.
  • Authors:
    • Tammeorg,Priit
    • Simojoki,Asko
    • Makela,Pirjo
    • Stoddard,Frederick L.
    • Alakukku,Laura
    • Helenius,Juha
  • Source: Plant and Soil
  • Volume: 374
  • Issue: 1-2
  • Year: 2014
  • Summary: We studied the effect of different biochar (BC) application rates on soil properties, crop growth dynamics and yield on a fertile sandy clay loam in boreal conditions. In a three-year field experiment conducted in Finland, the field was divided into three sub-experiments with a split-plot experimental design, one for each crop: wheat (Triticum aestivum), turnip rape (Brassica rapa), and faba bean (Vicia faba). The main plot factor was BC rate (0, 5 and 10 t DM ha(-1)) and the sub-plot factor was the N-P-K fertiliser rate. Soil physico-chemical properties as well as plant development, yield components and quality were investigated. BC addition did not significantly affect the soil chemical composition other than the increased C and initially increased K contents. Increased soil moisture content was associated with BC application, especially at the end of the growing seasons. BC decreased the N content of turnip rape and wheat biomass in 2010, thus possibly indicating an initial N immobilisation. In dry years, the seed number per plant was significantly higher in faba bean and turnip rape when grown with BC, possibly due to compensation for decreased plant density and relieved water deficit. However, the grain yields and N uptake with BC addition were not significantly different from the control in any year. Even though BC application to a fertile sandy clay loam in a boreal climate might have relieved transient water deficit and thereby supported yield formation of crops, it did not improve the yield or N uptake.
  • Authors:
    • De Nocker, L.
    • Aertsens, J.
    • Gobin, A.
  • Source: Land Use Policy
  • Volume: 31
  • Year: 2013
  • Summary: Purpose: This paper aims at indicating the potential of agricultural measures in sequestering carbon as an option for climate change mitigation. The related value for society is estimated. Principle results: Agricultural practices like agroforestry, introducing hedges, low and no tillage and cover crops have an important potential to increase carbon sequestration. The total technical potential in the EU-27 is estimated to be 1566 million tonnes CO2-equivalent per year. This corresponds to 37% of all CO2-equivalent emissions in the EU in 2007. The introduction of agroforestry is the measure with the highest potential, i.e. 90% of the total potential of the measures studied. Taking account only of the value for climate change mitigation, the introduction of agroforestry is estimated to have a value of 282 euro/ha in 2012 that will gradually increase to 1007 euro/ha in 2030. Major conclusions: This implies that there is a huge potential which represents an important value for society in general and for the agricultural sector in specific. At the European level, only in the last few years policy makers have recognized the important benefits of agroforestry. In their rural development programmes some European countries now support farmers to introduce agroforestry. But still the current level of support is only a small fraction of the societal value of agroforestry. If this value would be fully recognized by internalizing the positive externality, we expect that agroforestry will be introduced to a very large extent in the next decades, in Europe and the rest of the world, and this will importantly change the rural landscapes. (C) 2012 Elsevier Ltd. All rights reserved.
  • Authors:
    • Nuutinen, V.
    • Ketoja, E.
    • Heikkinen, J.
    • Regina, K.
  • Source: Global Change Biology
  • Volume: 19
  • Issue: 5
  • Year: 2013
  • Summary: Soil organic matter not only affects soil properties and productivity but also has an essential role in global carbon (C) cycle. We studied changes in the topsoil C content of Finnish croplands using a dataset produced in nationwide soil monitoring. The monitoring network consisting of fields on both mineral and organic soils was established in 1974 and resampled in 1987, 1998, and 2009. Over the monitoring period from 1974 to 2009, cultivated soils showed a continuous decline in C concentration (g kg -1). In organic soils, C concentration decreased at a mean rate of 0.2-0.3% yr -1 relative to the existing C concentration. In mineral soils, the relative decrease was 0.4% yr -1 corresponding to a C stock (kg m -2) loss of 220 kg ha -1 yr -1. The change in management practices in last decades toward increasing cultivation of annual crops has contributed to soil C losses noted in this study. The results, however, suggest that the C losses result partly from other processes affecting cultivated soils such as climatic change or the continuing long-term effect of forest clearance. We estimated that Finnish cropland soils store 161 Tg carbon nationwide in the topmost 15 cm of which 117 Tg is in mineral soils. C losses from mineral soils can therefore total up to 0.5 Tg yearly.
  • Authors:
    • Martikainen, P. J.
    • Heitto, auri
    • Marushchak, M. E.
    • Lind, S. E.
    • Shurpali, N. J.
    • Huttunen, J. T.
    • Hyvonen, N. P.
  • Source: BOREAL ENVIRONMENT RESEARCH
  • Volume: 18
  • Issue: 2
  • Year: 2013
  • Summary: Hyvonen, N. P., Huttunen, J. T, Shurpali, N. J., Lind, S. E., Marushchak, M. E., Heitto, L. & Martikainen, R J. 2013: The role of drainage ditches in greenhouse gas emissions and surface leaching losses from a cutaway peatland cultivated with a perennial bioenergy crop. Boreal Env. Res. 18: 109-126. We studied greenhouse gas (GHG) emissions from drainage ditches and leaching losses in a boreal cutaway peatland cultivated with reed canary grass (Phalaris arundinacea) for bioenergy. The objectives of the study were to assess to what extent GHG emissions from drainage ditches and leaching of carbon and nutrients via surface drainage contribute to the total losses of carbon and nitrogen from the site. The emissions of CH4, N2O and CO2 were measured with static chamber methods for three years and leaching losses for seven years. On average, the drainage ditches (covering 6% of the study site area) released 10% of the total CH4 emission (0.33 g m(-2) a(-1)), and 1% and 5% of the total N2O and CO2 emissions, respectively. Leaching of total nitrogen and phosphorous were 0.31 and 0.03 g m(-2) a(-1), respectively. Leaching values were lower than those reported for agricultural catchments in general.
  • Authors:
    • Penttila,T.
    • Minkkinen,K.
    • Ojanen,P.
  • Source: Forest Ecology and Management
  • Volume: 289
  • Issue: February
  • Year: 2013
  • Summary: We estimated the soil CO2 balance of 68 forestry-drained boreal peatland sites in Finland by subtracting the litter input to soil from the CO2 efflux from soil. We also measured soil-atmosphere fluxes of CH4 and N2O and the CO2 sink of the growing tree stand in order to assess the current greenhouse gas impact of the study sites. The soil was, on average, a CO2 source of +190 +/- 70 g m(-2) year(-1) at the fertile Herb-rich and Vaccinium myrtillus type sites, but a CO2 sink of -70 +/- 30 g m(-2) year(-1) at the poor Vaccinium vitis-idaea and Dwarf shrub type sites. The source increased at the fertile and the sink decreased at the poor sites as the water table deepened. The source at the fertile sites also increased by increasing temperature sum, the highest CO2 sources being around +1000 g m(-2) year(-1) at well drained sites in Southern Finland. Both fertile and poor sites had a climate cooling impact. The sink in CO2 equivalents at the fertile sites was -690 +/- 90 g m(-2) year(-1) and at the poor sites -540 +/- 70 g m(-2) year(-1). The greater sink at the fertile sites was due to clearly better tree growth, their tree stand CO2 sink being -880 +/- 60 g m(-2) year(-1) compared to the -490 +/- 60 g m(-2) year(-1) at the poor sites. Ditching-based forestry can be climatically sustainable at nutrient-poor boreal peatlands since the peat soil continues to be a CO2 sink even after drainage. At the fertile sites, forestry will inevitably lead to loss of carbon in the long term, unless the tree biomass is stored after cuttings, for example in wooden buildings or as biochar in agricultural soils. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Pearson, M.
  • Source: Dissertationes Forestales
  • Issue: 159
  • Year: 2013
  • Summary: This dissertation investigated the impacts of soil preparation after clearcutting Scots pine ( Pinus sylvestris L.) forest on thick-peated soil from silvicultural and climatic standpoints. Three growing seasons after outplanting, mounding most effectively secured seedling survival, growth, and vitality through improved soil aeration of the planting spot. However, other presumed benefits of mounding to seedlings such as warmer soil temperatures and faster organic matter decomposition were not confirmed here. Regeneration in scalps was unsuccessful due to waterlogged soil. Importantly when scalping, only the humus layer should be scraped off without creating depressions in the peat. Seedling tolerance to desiccated as well as waterlogged peat soil over one growing season was remarkable in controlled conditions as mortality remained low. Drought stress was, however, plainly evident in seedlings as root and shoot growth, fractional colonization of ectomycorrhizal fungi, and root hydraulic conductance were all reduced. Nevertheless, maintenance of rather high photochemical efficiency (F v/F m) especially in current-year needles despite harsh drought seemed to indicate a potential for seedling recovery. Polyamine analysis also revealed that new needles are preferred in protecting the different parts of the seedlings against drought stress. Conversely, wet-stressed seedlings exhibited few signs of suffering. It was also demonstrated how the experimental environment - a controlled versus field setting - influences seedling tolerance to stress. The differing moisture levels within comparable microsites - dry vs. wet scalps and ditch vs. inverted mounds - had little influence on seedling growth and condition although physiological upset (i.e., F v/F m) was evident within scalps. Namely, the wetter the soil was, the lower F v/F m was. The fear of soil preparation accelerating GHG emissions, particularly CO 2, from peat into the atmosphere appears unwarranted at least on nutrient-poor, boreal forestry-drained peatland sites. The overall climatic impacts of mounding and scalping three years after application were neutral compared to leaving soil unprepared. The core findings of this research support mounding as the best alternative on nutrient-poor, drained peatland sites when the goal is to maximize the regeneration success of Scots pine after clearcutting with minimal impact on soil GHG emissions. In the future, development of soil preparation methodology is particularly deserving of further attention. While it may not be the sexiest research topic in the worldwide rat race of the modern day, it is nonetheless of substantial importance in a country highly specialized not only in the utilization but also the rejuvenation of wood resources on drained peatlands.
  • Authors:
    • Roger-Estrade, J.
    • Basch, G.
    • Moreno, F.
    • Soane, B. D.
    • Ball, B. C.
    • Arvidsson, J.
  • Source: Soil & Tillage Research
  • Volume: 118
  • Year: 2012
  • Summary: Recent literature on no-till is reviewed with particular emphasis on research on commercial uptake and environmental concerns in northern, western and south-western Europe. Increased interest in no-till, and minimum or reduced tillage, results from changes in the economic circumstances of crop production, the opportunity to increase the area of more profitable autumn-sown crops and increased concern about environmental damage associated with soil inversion by ploughing. Highly contrasting soil and climate types within and between these regions exert a strong influence on the success of no-till. While no-till may often result in crop yields which equal or exceed those obtained after ploughing, modest reductions in yield may be tolerated if production costs are lower than with ploughing. The relative costs of fuel and herbicides have changed appreciably in recent years making no-till more attractive commercially. While effective weed control is an essential aspect of no-till, current herbicide technology may not yet fully achieve this. In northern regions no-till usually allows earlier drilling of winter-sown crops but will give lower soil temperature and higher moisture content in spring, causing delayed drilling of spring-sown crops. No-till soils have greater bulk density and bearing capacity than ploughed soils with a pronounced vertical orientation of macroporosity allowing penetration of roots and water, especially in view of the increased population of deep-burrowing earthworms. Particular care must be taken with no-till to minimise soil damage at harvest and to ensure the even distribution of crop residues prior to drilling. Reduced erosion and runoff after adoption of no-till are widely observed and are of particular importance in southwestern Europe. No-till reduces losses of phosphorus in runoff and, in some cases, reduces the loss of nitrate through leaching. Emissions of greenhouse gases CO 2 and N 2O from no-till soils are highly variable and depend on complex interactions of soil properties. Emission of CO 2 from fuel during machinery usage is always appreciably reduced with no-till. Increased soil organic carbon in surface layers of no-till soils is widely found but may not be associated with increased carbon sequestration throughout the profile. The evaluation of the relative carbon balance for no-till and ploughing depends upon complex inter-relationships between soil and climate factors which are as yet poorly understood. Adoption of no-till could be encouraged by government financial assistance in recognition of environmental benefits, although future restrictions on the use of herbicides may be a deterrent. Opportunities for further research on no-till are outlined.
  • Authors:
    • Bjornstad, A.
    • He, X.
  • Source: Theoretical and Applied Genetics
  • Volume: 125
  • Issue: 1
  • Year: 2012
  • Summary: Oat is an important crop in Nordic countries both for feed and human consumption. Maintaining a high level of genetic diversity is essential for both breeding and agronomy. A panel of 94 oat accessions was used in this study, including 24 museum accessions over 100- to 120-year old and 70 genebank accessions from mainly Nordic countries and Germany, covering different breeding periods. Sixty-one polymorphic SSR, 201 AFLP and 1056 DArT markers were used to evaluate the past and present genetic diversity of the Nordic gene pool. Norwegian accessions showed the highest diversity, followed by Swedish and Finnish, with German accessions the least diverse. In addition, the Nordic accessions appeared to be highly interrelated and distinct from the German, reflecting a frequent germplasm exchange and interbreeding among Nordic countries. A significant loss of diversity happened at the transition from landraces and old cultivars to modern cultivars. Modern oat originated from only a segment of the landraces and left the remainder, especially black oat, unused. However, no significant overall diversity reduction was found during modern breeding periods, although fluctuation of diversity indices was observed. The narrow genetic basis of the modern Nordic gene pool calls for increasing genetic diversity through cultivar introduction and prebreeding based on neglected sources like the Nordic black oat.
  • Authors:
    • Nerg, A.
    • Kivimaenpaa, M.
    • Hartikainen, K.
    • Holopainen, T.
  • Source: Botany-Botanique
  • Volume: 90
  • Issue: 2
  • Year: 2012
  • Summary: To study the possible differences in tropospheric ozone (O 3) tolerance of oat ( Avena sativa L.) and wheat ( Triticum aestivum L.), two oat and two wheat cultivars were exposed to 0, 50, or 100 nL.L -1 O 3 concentrations in growth chambers. Measurements on volatile organic counpound emission and physiological, biochemical, and leaf structural characteristics were conducted with 2- and 4-week-old seedlings. Neither of the studied species was particularly O 3 sensitive, but O 3 sensitivity should rather be defined on the basis of the characteristics of the cultivars within species. Visible leaf injuries increased with leaf age and with increasing O 3 concentration. Net photosynthesis ( Pn), stomatal conductance ( gs), and chlorophyll fluorescence ( Fv/ Fm) of 2-week-old seedlings were more detrimentally affected by O 3 compared with older seedlings. Wheat generally invested more in photosynthesis and related processes, such as gs, Fv/ Fm, concentrations of Rubisco, chlorophylls and carotenoids, and synthesis of starch compared with oat. O 3 increased Rubisco concentration in 2-week-old and carotenoid concentration in 4-week-old seedlings, especially in wheat. Lower extent of O 3-caused visible leaf injuries in the other oat cultivar can supposedly be explained by its low stomatal conductance and high monoterpene production.