Browsing by Subject "agroekologia"

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  • Riesinger, Paul (Helsingin yliopisto, 2010)
    With respect to resource management and environmental impact, organic farming offers rationales for agricultural sustainability. However, agronomic productivity is usually higher with conventional farming. This work aimed at investigating two factors of major importance for the agronomic productivity of organic crop husbandry, nitrogen (N) supply through symbiotic N fixation (SNF) and weed occurrence. Perennial red clover-grass leys and spring cereal crops subjected to regular agricultural practices were studied on 34 organic farms located in the southern and the north-western coastal regions of Finland. Herbage growth, clover content as a proportion of the ley and extent of SNF in perennial leys, and the occurrence of weed species and weed-crop competition in spring cereal stands were related to climate conditions, soil properties, and management measures. The herbage accumulated from the first and the second cut of one- and two-year-old leys averaged 7.5 t DM ha-1 (SD ± 1.7 t DM ha-1); the clover content averaged 43.9% (SD ± 18.8%). Along with the clover content, herbage production decreased with ley age. Radiation use efficiency (RUE) correlated positively with clover proportion but despite low clover contents, three-year-old leys were still productive with regard to RUE. SNF in the accumulated annual growth of one- and two-year-old leys averaged 247.5 kg N ha-1 yr-1 (SD ± 114.4 kg N ha-1 yr-1). It was supposed that if red clover-grass leys constituted 40% of the rotation, then the mean N supply by SNF would be able to sustain two or three succeeding cereal crops (green manure and forage ley, respectively), yielding 3.0 to 4.0 t grain ha-1. Being a function of clover biomass, the SNF increased from the first to the second cut and thereafter declined with ley age. Coefficients of variation of clover contents (and SNF) between and within fields were around 50%, which was about twice as high as those of herbage production. The lower were the clover contents, the higher were the within-field variations of clover as a proportion of the ley. Low clover contents in one-year-old leys and increasing variability with ley age suggested that red clover growth was limited by poor establishment and poor overwintering. The proportions of clover in leys were lower and their variability was higher in the northwest than in the south. Soil properties, primarily texture and structure, had a major impact on clover proportion and herbage production, which largely explained regional differences in ley growth. Within-field variability of soil properties can be amended through site-specific measures, including drainage, liming, and applications of organic manures and mineral fertilizers. Overwintering and the persistence of leys can be improved by the choice of winter-hardy varieties, careful establishment and the appropriate harvest regime. Mean grain yields of spring cereal crops amounted to 3.2 t ha-1 in the south and 3.6 t ha-1 in the northwest. At 570 and 565 m-2 for the south and northwest respectively, mean weed densities did not differ between the regions, whereas the respective mean weed biomass of 697 and 1594 kg dry weight ha-1, respectively did differ. Weed abundance varied remarkably between single fields. The number of weed species was higher in the south than in the northwest. For example, Fumaria officinalis and Lamium spp. were found only in the south. Frequencies and abundances of Lapsana communis, Myosotis arvensis, Polygonum aviculare, Tripleurospermum inodorum, and Vicia spp. were higher in the south, whereas those of Elymus repens, Persicaria spp. and Spergula arvensis were higher in the northwest. The number of years since conversion to organic farming, i.e. long-term management, was one of the variables that explained the abundance of single weed species. E. repens was the weed species whose biomass increased most with the duration of organic farming. Another significant variable was crop biomass, which was affected by short-term management. The presence of different weed species was related to the duration of organic farming and to low crop yield. This finding demonstrated that it was not the organic farming regime per se, which resulted in high weed infestation and low yielding crops, but failures in the understanding and the management of organic farming systems. Successful weed control relies on farm- and field-specific long- and short-term management approaches. The agronomic productivity of ley and spring cereal crops managed by full-time farmers with an interest in organic farming was on the same level as of the mean for conventional farming. Given the many options for further improvements of the agronomic performance of organic arable systems, organic farming offers foundations for the development of sustainable agriculture. The main threat to the sustainability of farming in Finland, both conventional and organic, is the spatial separation of crop production and animal husbandry by region, along with the simplification of associated crop rotations.
  • Heikkinen, Jaakko (Helsingin yliopisto, 2016)
    Carbon (C) that is stored in soils is the principal terrestrial C pool. The soil stores twice as much C compared to that which is stored in the atmosphere. Therefore, even a slight change in soil C stock can have a huge effect on atmospheric carbon dioxide concentration and global climate. Agricultural soils play a key role in this system: they cover about 38% of the land area world-wide and are intensively managed. The soil C also greatly contributes to sustainable food production as soil organic matter is to large extent made of C. The aim of the research carried out for this thesis was to determine the nationwide soil C stock in Finnish arable mineral soils, study historic trends of C stock in soils and examine possible factors that affect those trends. Knowing the past can also give us insights into future trends in soil C and its climatic impact. The data presented in this thesis were obtained from the Finnish national soil monitoring network and long-term field trials in Uppsala Sweden and Pushchino Russia. In addition two process-based soil C models, namely: Yasso07 and RothC, were used and their findings were compared with those of long-term field trials. Finnish arable lands were found to be rich in soil C. Mineral soils in Finland store between 41 and 67 Mg C ha-1 (0-15 cm) depending on the management, soil type and region. Nationwide the C stock in arable topsoil is about 117 Tg and although the deeper soils layers are poorly known the total soil C stock in mineral soils of Finland can be estimated to be about 300 Tg. The C stock of mineral arable soils has decreased. The decrease was found to be 0.22 Mg C ha-1 yr-1 (0-15 cm soil layer) according to the national soil inventory network of Finland and 0.29-0.36 Mg C ha-1 yr-1 (0-100 cm soil layer) according to results obtained by the Yasso07 model. The annual C emissions from agricultural mineral soils are about 0.5 Tg, which represents about 2.5% of the total greenhouse gas emissions in Finland. Process based modelling in which the past land use history was taken into account clearly indicated that the nationwide decrease can be linked to the past change in land use from forest to agricultural land, which has created the ongoing soil C loss. Finnish arable lands are relatively young and it is likely that they are still losing the soil C that had been accumulated when these lands were part of boreal forest systems. Likewise the thesis indicates that the soil C loss partly results from the intensification in cultivations that took place in the past decades and that cultivation of annual crops has become more common. Cultivation of annual crops increases the soil disturbance due to tillage and decreases the below-ground C influx into the soil. The composition of litter quality was also shown to have considerable effects on the ease of decomposition of organic matter. Previously, the Yasso07 model had been mainly tested and used in forested soils. Findings in this thesis demonstrate that this model can also be applied to agricultural mineral soils under boreal conditions. The fact that the model works equally well under various environmental conditions indicates that the accumulation of soil C is largely controlled by litter input, climate and litter chemical quality. The comparison between simulations and experimental data obtained from field trials showed that the results of Yasso07 model are comparable with those of the RothC model, which is currently one of the most widely used soil C models for agricultural applications. The decreasing trend of soil C stocks found in this thesis has undesirable ramifications for climate, environment and sustainable food production. The changes in topsoil C might reflect the condition of soil C in deeper soil layers. Therefore, it would be crucial to investigate the storage of deep soil C and the long-term effects of agricultural practices on it.
  • Kärkkäinen, Jani (Helsingin yliopisto, 2018)
    This study investigates the effects of oil palm smallholding, wealth, and ecosystem services produced by oil palm dominated agroecosystem in the villages of Tanjung Bering and Betung in Sumatra, Indonesia in 2008. The cultivation of oil palm has many environmental and socio-economic impacts. In particular, indigenous peoples are vulnerable stakeholders between the expanding oil palm plantations. Oil palm industry has sought to find sustainable models for palm oil production: the inclusion of indigenous peoples to oil palm development is an essential part of this. The purpose of the study is to chart the situation and to investigate the impact of the oil palm smallholding for the well-being of local indigenous people, and to provide information for the sustainable decision-making. The study is based on household interviews in the area of the Petalangan ethnic group. The interviews were added to a relational database, which was used to provide variables on ecosystem services, economy and well-being for statistical analysis. Statistical analysis was carried out mainly by cross-tabulating the mentioned variables with wealth and the oil palm smallholding status, significance has been defined with the Pearson’s khii-test. Interpretation and analysis of the results has been made in the framework of ecosystem services by the Millennium Ecosystem Assessment. Oil palm smallholding highly significantly increased households’ income, and wealth increased highly significantly household’s well-being. The fragmented oil palm dominated agroecosystem was still providing ecosystem services to households. The wealth reduced households’ dependency on most ecosystem services as well as substituted many of them. It is concluded based on this study that in the oil palm dominated agroecosystem, oil palm smallholding and higher income affects very favourable to the households’ well-being, and vice versa non-oil-palm-smallholding and poverty predicts ill-being.
  • Toivonen, Marjaana (Helsingin yliopisto, 2016)
    Environmental fallows are fields that aim to produce environmental benefits instead of agricultural products. In many European countries, the establishment and management of fallows is funded via agri-environmental programmes. This thesis focuses on the biodiversity benefits of environmental fallows in boreal farmland. I examined the impacts of different fallow types and landscape structure on the diversity and species composition of multiple taxa in fallows. I also aimed to evaluate what fallow types, and in what landscape context, are needed to contribute to different biodiversity objectives: the promotion of conservation concern species, overall species diversity or ecosystem services. Species richness and composition of the studied species groups differed substantially between fallow types, and landscape context further modified the value of fallows. Perennial fallows sown with meadow plants supported high plant species richness and bumblebee abundance. Old grassland fallows benefitted both butterflies in general, and butterflies and bumblebees with narrow niches and low dispersal capacities. The positive impacts were emphasized when long-term fallows were located in complex landscapes. High forest cover in the surrounding landscape increased plant species richness in perennial fallows. The breeding density of open farmland birds was highest in short-term meadow fallows in landscapes rich in perennial grasslands. Foraging edge birds preferred short-term meadow fallows in open landscapes and long-term grassland fallows in forested landscapes. Vegetation of annual fallow types game fields and landscape fields differed considerably from perennial fallows and other non-crop biotopes, thus enhancing landscape heterogeneity. My results show that the biodiversity benefits of fallows can be enhanced by adapting fallows to the landscape context and to specific conservation objectives. If the objective is to support species of conservation concern, managing long-term fallows in complex landscapes rich in perennial grasslands is probably the best strategy. Overall biodiversity can also be enhanced in short-term fallows, especially if they are sown with diverse seed mixtures of species that are not too competitive in field conditions. Depending on the sown species, short-term fallows provide good possibilities to enhance landscape heterogeneity and promote ecosystem services. Future studies should consider the specific roles of forest and perennial grasslands in driving the effectiveness of agri-environment schemes. In addition, the impacts of agri-environment schemes, including fallows, on realized ecosystem services should be investigated.
  • Korpela, Eeva-Liisa (Helsingin yliopisto, 2014)
    This thesis focuses on the responses of bumblebees and diurnal Lepidoptera (butterflies and diurnal moths) to habitat establishment on farmland. In the first paper, I studied the benefits of long-term set-aside establishment for the focal species groups. Focusing on another on-field measure, sown wildflower strips, I studied the ability of sown strips to promote three different aspects of flower-visiting insect diversity: pollination service availability, species diversity and species of conservation concern. As an off-field measure, I studied the benefits of logging in field-forest ecotones in terms of the same three aspects of insect diversity. Finally, I studied differences in butterfly and moth mobility as well as the role of species traits in butterfly mobility in a release experiment. Based on my results, long-term set-asides and wildflower strips are very effective in enhancing pollination service availability, as long as they are sown with nectar and pollen plants favored by bumblebees. Species diversity also increased rather quickly in the wildflower strip and logging experiments. Furthermore, my results showed that habitat specialist butterflies of conservation concern are best promoted in relatively forested landscapes and that logging in field-forest ecotones promotes them more effectively than establishing wildflower strips on cultivated fields. As regards to diurnal Lepidoptera in general, set-aside field parcels should be left in place for several, preferably for at least for five years, as it takes time for less mobile species to disperse to the created habitat patches and to establish local populations. The set-aside experiment showed that the colonization speed in butterflies and diurnal moths was strongly connected with body size measured by wingspan, and that diurnal moths were on the average slower colonizers than butterflies. The results of the mobility experiment confirmed the important role of wingspan in butterflies, but also connected mobility with release habitat suitability: those species for which the experimental set-aside was most suitable habitat, namely grassland species, showed less tendency to disperse after the experimental releases. All three studied measures can be applied in conventional agriculture in Finland. Combining different measures at landscape and regional levels is likely to promote multiple aspects of flower-visiting insect diversity. The potential of habitat creation in field-forest ecotones in particular is substantial in the Finnish countryside, as many farmers are also forest owners. Furthermore, as habitat establishment adds different grassland patches into the landscape, also less mobile species and species with specific habitat requirements are likely to benefit.
  • Rimhanen, Karoliina (Helsingin yliopisto, 2016)
    Sub-Saharan Africa (SSA) is one of the world´s most vulnerable regions to climate change. Even though the proportion of greenhouse gas emissions produced in SSA is low, the agricultural sector has an enormous potential for climate change mitigation. The aim here is to increase understanding of the potential of climate change mitigation to enhance food security. The focus of the study is to identify the determinants of this potential, to estimate the possibilities to increase the proportion of carbon ending up in soil and to quantify the soil carbon sequestration potential of agroecological practices in Ethiopia. Identification of the determinants of the potential of climate change mitigation to enhance food security was based on in-depth interviews and focus group discussions. The assessment of carbon flows was based on interviews and sampling. Material flow analysis and carbon balance counting was used for tracking the carbon flows and for estimating the carbon losses. Quantification of the carbon sequestration potential of the agroecological practices was based on comparison of the existing plot pairs, including a plot with an agroecological practice and an adjacent plot with a traditional practice. Soil carbon sequestration in agricultural soil was considered as the most important means to promote climate change mitigation and to enhance food security. The primary factors enhancing food security were perceived to be increasing agricultural productivity and incomes from marketed crops. On the Ethiopian farms, 8 12% of the total harvested carbon was used for soil and 9 16% for food. The largest carbon losses were due to biomass burning and livestock metabolism. The proportion of carbon used for soil could mainly be increased by reducing gaseous losses. Agroforestry led to 11.4 t ha-1, restrained grazing to 9.6 t ha-1 and terracing to 1.7 t ha-1 greater soil carbon stock than did their control plots. The estimates are higher than those based on process-modelling studies. The difference probably resulted from the development and validation of process models under conditions that differ from those in East-Africa. From the results it can be concluded that the most important means perceived as enhancing food security through climate change mitigation is improving food availability through soil carbon sequestration. The proportion of carbon used for energy determines the proportion ending up in soil. Alternative energy sources are needed to increase the flow of carbon to soil. The soil carbon sequestration potential in Ethiopian agriculture is greater than previously estimated. Climate conditions and intercropping treatment should be incorporated into process models to improve their adequacy for farming systems in East Africa.
  • Risku-Norja, Helmi (Helsingin yliopisto, 2011)
    Agriculture is an economic activity that heavily relies on the availability of natural resources. Through its role in food production agriculture is a major factor affecting public welfare and health, and its indirect contribution to gross domestic product and employment is significant. Agriculture also contributes to numerous ecosystem services through management of rural areas. However, the environmental impact of agriculture is considerable and reaches far beyond the agroecosystems. The questions related to farming for food production are, thus, manifold and of great public concern. Improving environmental performance of agriculture and sustainability of food production, sustainabilizing food production, calls for application of wide range of expertise knowledge. This study falls within the field of agro-ecology, with interphases to food systems and sustainability research and exploits the methods typical of industrial ecology. The research in these fields extends from multidisciplinary to interdisciplinary and transdisciplinary, a holistic approach being the key tenet. The methods of industrial ecology have been applied extensively to explore the interaction between human economic activity and resource use. Specifically, the material flow approach (MFA) has established its position through application of systematic environmental and economic accounting statistics. However, very few studies have applied MFA specifically to agriculture. The MFA approach was used in this thesis in such a context in Finland. The focus of this study is the ecological sustainability of primary production. The aim was to explore the possibilities of assessing ecological sustainability of agriculture by using two different approaches. In the first approach the MFA-methods from industrial ecology were applied to agriculture, whereas the other is based on the food consumption scenarios. The two approaches were used in order to capture some of the impacts of dietary changes and of changes in production mode on the environment. The methods were applied at levels ranging from national to sector and local levels. Through the supply-demand approach, the viewpoint changed between that of food production to that of food consumption. The main data sources were official statistics complemented with published research results and expertise appraisals. MFA approach was used to define the system boundaries, to quantify the material flows and to construct eco-efficiency indicators for agriculture. The results were further elaborated for an input-output model that was used to analyse the food flux in Finland and to determine its relationship to the economy-wide physical and monetary flows. The methods based on food consumption scenarios were applied at regional and local level for assessing feasibility and environmental impacts of relocalising food production. The approach was also used for quantification and source allocation of greenhouse gas (GHG) emissions of primary production. GHG assessment provided, thus, a means of crosschecking the results obtained by using the two different approaches. MFA data as such or expressed as eco-efficiency indicators, are useful in describing the overall development. However, the data are not sufficiently detailed for identifying the hot spots of environmental sustainability. Eco-efficiency indicators should not be bluntly used in environmental assessment: the carrying capacity of the nature, the potential exhaustion of non-renewable natural resources and the possible rebound effect need also to be accounted for when striving towards improved eco-efficiency. The input-output model is suitable for nationwide economy analyses and it shows the distribution of monetary and material flows among the various sectors. Environmental impact can be captured only at a very general level in terms of total material requirement, gaseous emissions, energy consumption and agricultural land use. Improving environmental performance of food production requires more detailed and more local information. The approach based on food consumption scenarios can be applied at regional or local scales. Based on various diet options the method accounts for the feasibility of re-localising food production and environmental impacts of such re-localisation in terms of nutrient balances, gaseous emissions, agricultural energy consumption, agricultural land use and diversity of crop cultivation. The approach is applicable anywhere, but the calculation parameters need to be adjusted so as to comply with the specific circumstances. The food consumption scenario approach, thus, pays attention to the variability of production circumstances, and may provide some environmental information that is locally relevant. The approaches based on the input-output model and on food consumption scenarios represent small steps towards more holistic systemic thinking. However, neither one alone nor the two together provide sufficient information for sustainabilizing food production. Environmental performance of food production should be assessed together with the other criteria of sustainable food provisioning. This requires evaluation and integration of research results from many different disciplines in the context of a specified geographic area. Foodshed area that comprises both the rural hinterlands of food production and the population centres of food consumption is suggested to represent a suitable areal extent for such research. Finding a balance between the various aspects of sustainability is a matter of optimal trade-off. The balance cannot be universally determined, but the assessment methods and the actual measures depend on what the bottlenecks of sustainability are in the area concerned. These have to be agreed upon among the actors of the area
  • Saarinen, Merja (Helsingin yliopisto, 2018)
    Life cycle assessment (LCA) is the most used methodology for assessing the environmental impacts of products, such as food. Comparison between products should be based on a common functional unit (FU). The FU describe a function or functions of the product against which life cycle impacts should be related to. For the food products nutritional value is not typically present in currently used FUs. This dissertation develops and analyses ways to link nutritional aspects into LCA of food so that relevant additional information can be achieved compared to the current LCA practice. Its focus is at analysing the applicability of various different FUs at a product and portion level where a primary consumer choice operates. The alternative nutritional FUs developed and analysed are: 1) standardised meals, 2) mass-based FUs for individual nutrients, and 3) the nutrient indexes of products. Altogether 66 food products and 29 lunches consisting of 27 food items were assessed using LCA for climate impact as an impact category. At product level, a product group specific approach is emphasized, and protein source foods are highlighted as an example of a product group. According to the results the use of a nutrient index based on recommended nutrients as an FU is proposed to be, currently, the most suitable general methodology for including nutrition in a food LCA on a product scale. The index which consists of nutrients to be limited is proposed to be combined with these indexes while defining sustainable products. Mass-based FUs for individual nutrients is, instead, proposed to be applied only restrictedly in the cases of scare but essential nutrients which exist only in a few food products. Additionally, the use of the standardised portion as an FU provides relevant additional information related to the LCA of individual products, such as meat or vegetables, which alone are not able to provide adequate nutrient composition intake. The plate model is well-known and the visual element makes it easy to understand. In the common scientific and popular discourse, the message has been clear when reasoning for sustainable food consumption: one should avoid animal-based foods, particularly beef because beef has by far the greatest environmental impact. According to the results of this dissertation, however, particularly beef, in addition to for example hemp seeds, would benefit from the inclusion of nutrition criteria in food LCA on a product scale. The same issue can partly be seen at a more general level also on the portion scale assessment. According to the assessment on the portion scale, the choice of salad also makes a substantial difference from the point of view of the climate impact if grown in greenhouses. The choice of starch, even rice, was without major implications in the context of the plate model. Based on the results, the whole picture of the climate impact can be received, only, by including into the assessment 1) the production processes that lead to eatable products and by the inclusion of 2) the combination the functions of the food groups, which have different specific roles in the nutrition. In summary, nutrition should be taken into account in versatile ways in the food LCA. Each assessment pattern assessed in this dissertation has its own strength, and vice versa none of the methods can provide an all-inclusive understanding.
  • Rummukainen, Hanna (Helsingin yliopisto, 2018)
    As the world's population keeps growing, it is vital to focus on efficiency of agriculture. At this moment, food production is happening at the cost of natural resources. Significant amounts of nitrogen and phosphorus flow in nature as waste and enhance climate change and eutrophication of waters. Nutrient recycling is an essential part of sustainable and responsible agriculture. By combining animal and crop production it is possible to recycle some of the nutrients in an agroecosystem, since manure and other animal waste include nutrients that were given to the feed plants. Meat bone meal (MBM) includes 50 % protein, 35 % ash and 8–12 % fat (NPK 8–5–1). Previous fertilization experiments with MBM have already given promising results. The aim of this study is to find out, if there are significant differences between the fertilization potentials of mineral and MBM fertilizers, and if the dosage of these fertilizers affects the mean yields of malt barley (Hordeum vulgare var. distichon). The fertilization effects of two MBM fertilizers, “Viljo” and “Kana-Viljo”, were compared to mineral fertilizer and chicken manure on malt barley in a field experiment in 2015. Each fertilizer was applied on two nitrogen levels (80 and 160 kg N/ha). The mean yields per hectare and hectolitre weights were compared to the ones given by an unfertilized control member. Although none of the organic fertilizers gave as much improvement in the yield as the mineral fertilizer, all the fertilized yields were significantly bigger than the control member’s. Between the hectolitre weights there was no significant difference and doubling the supply of N did not give significant difference to yields. There was also no interaction between the N supply and the fertilizer type. Applying a lot of N on malt barley increases the quantity of protein in a grain, so the higher N supply may even affect the quality of the yield. The challenge of MBM is its slowly releasing P, so the results on the same field could have been different if the test had been repeated the following year. The used barley Streif is known to be an early cultivar and the field was fertilized just before sowing, so all the N in MBM may not have had enough time to release for the crop to use in this study. It is to be noted that significant results of MBM fertilization were gotten with this little data, it is recommended to keep on researching the potential of MBM as an organic fertilizer.
  • Örö, Nelly (Helsingin yliopisto, 2018)
    Meat and bone meal is a by-product of rendering industry. It contains significant amounts of nutrients, for example 2720 tonnes per year phosphorus in Finland. The use of meat and bone meal in agriculture ceased because of the mad cow disease in 1994. Meat and bone meal has been proved to nearly equal mineral fertilizers both economically and in fertilization effect with many crops. The use of high phosphorus content meat and bone meal as fertilizer decreases the need for non-renewable phosphorus resources and closes food system nutrient cycles. The objectives of this thesis were to consider the suitability of meat and bone meal in potato production and to estimate the recycling potential of meat and bone meal in potato production in Finland. The recycling potential was calculated as a ratio between the annual phosphorus demand in potato production and the amount of phosphorus in meat and bone meal produced in Finland. The mean yields of potato as well as the fertilization rates in agri-environment measures and the plant-available proportion of meat and bone meal were used in calculation. The annual phosphorus demand of potato production was estimated as 1100 tonnes and the amount of plant-available phosphorus in meat and bone meal was estimated as 1630 tonnes. This number includes a category 1 disease risk material which must currently be disposed of. The recycling potentials of meat and bone meal were calculated as 67 % and 74 % for all the material and excluding the category 1 material, respectively. Consequently, the amount of phosphorus in meat and bone meal can supply the demand in potato production. Meat and bone meal is a long-term phosphorus fertilizer and suitable for potato production in Finnish conditions if nitrogen and potassium are supplemented to meet the crop’s demand with other fertilizer products. It’s also an advantage that meat and bone meal is accepted in organic production. In a recycling nutrients point of view, the utilization of meat and bone meal as a fertilizer for instance in potato production is a good opportunity to return nutrients to the agroecosystem’s cycle.
  • Syvänen, Marko (Helsingfors universitet, 2011)
    Besides farms’ main plant and animal products, meat and bone meal (MBM) represents agroecosystems’ biggest outward flow of nutriuents. MBM contains plenty of the main plant nutrients nitrogen, phosphorus and calcium (N ~8%, P ~5%, Ca usually ~10-15%, depending of the amount of bone matter), plus a little potassium (~1% or less). MBM has been proven efficient fertilizer on many plants, and it is also allowed for use in organic farming in EU. The most notable risk of MBM use relates to TSE-diseases (BSE for cattle, scrapie for sheeps and goats, and vCJD for humans). Its feed usage has been restricted in many countries since the BSE-crisis emerged in 1980’s. The rise of BSE was attributed to feeding cattle with MBM of cattle origin. Also feeding MBM to fur animals might pose a TSE-risk. However, assessing on the base of the studies included in this thesis, the TSE-risk from fertilizer use of MBM appears to be rather small. Still, a prerequisite of this is that all appropriate precautions are followed in the production and handling of MBM as well as when using it. By increasing the fertilizer use of MBM we would be able to considerably improve the nutrient cycle of phosphorus and other nutrients in our food systems. MBM is a renewable resource. The fertilizer use of MBM would also diminish the dependency on non-renewable phosphorus-rich rocks, that are commonly used in fertilizers today. MBM-fertlization was compared with mineral fertilizers in sugar beet field trials located in Southwestern Finland in the years 2008 and 2009. The cultivars used were ‘Jesper’ in 2008 and ‘Lincoln’ in 2009. The MBM source was Honkajoki Oy’s Viljo Yleislannoite 8-4-3, of which 10% was a combination of potassium sulphate fertilizer (42% K, 18% S) and plant-based side products. Viljotrials of 2009 also included added potassium sulphate to cover the nutrient requirements of sugar beet (60 kg K/ha). The plain Viljo-fertilizer produced yields that were significantly lower than control, but still above the Finnish average yields. When used in combination with mineral fertilizer (10-25% of the N content) the Viljo-trials produced yields close to the level of mineral fertilizers. The MBM-fertilization had a positive effect on beet quality in 2008 (measured in amino-N, K, and Na-concentrations), but in 2009 this effect was not present. Also, in 2008 one of the combinations (Viljo77%+NK1) produced a significantly higher sugar concentrations than the control. The sugar concentrations in 2009 didn’t differ significantly between fertilizers used but were excellent in all trials. These field trials indicate that MBM supplemented with potassium suphate has good potential for use as a fertilizer for sugar beet in Finnish conditions.
  • Chen, Lin (Helsingfors universitet, 2008)
    Meat bone meal (MBM) contains considerable amount of nutrients (~8% N, ~5% P and ~10 Ca). So it can be a potential organic fertilizer for different crops. Traditionally, the production of mineral N and P fertilizers is unsustainable due to the reliance on fossil fuels in case on N, and limited mineral resource stocks in case of P. Using complementary fertilizers which originate from organic waste materials is gaining interest. On the other hand, organic farms are usually lacking nutrient sources if animals are not kept on farm at the same time. Whether MBM can achieve similar crop yield and quality as the mineral fertilizer was studied. To quantify and qualify MBM use as an N and P fertilizer, two field experiments were done on spring barley and oat in 2000 and 2001. MBM and two types fur animal manure based fertilizers (FAMB and FAMBCF) were compared to mineral fertilizer PellonY3 in three N levels: 60, 90 and 120 kg/ha. MBM and FAMBCF gave the same grain yield as PY3. There was no additional yield increase by increasing N rate from 90 to 120 kg/ha. Four aspects of grain quality, namely 1000grain weigh, test weigh, protein content and protein yield were tested. MBM, FAMBCF and PY3 tended to have similar effect while FAMB had lower effect. Since MBM has a low N/P ratio, when it is applied to meet crop's N demand, P will be at surplus. So using crop rotation and green manure for organic farm and only applying N fertilizer for conventional farm after using MBM is recommended. Adding K in MBM is also necessary when there is a lack of K in soil since MBM had only ~1% K.
  • Tarmi, Sanna (Helsingin yliopisto, 2011)
    Agri-environmental schemes have so far resulted in only minor positive implications for the biodiversity of agricultural environments, in contrast to what has been expected. Land-use intensification has decreased landscape heterogeneity and the amount of semi-natural habitats. Field margins are uncultivated areas of permanent vegetation located adjacent to fields. Since the number of these habitats is high, investing in their quality may result in more diverse agricultural landscapes. Field margins can be considered as multifunctional habitats providing agronomic, environmental and wildlife services. This thesis aimed at examining the plant communities of different types of field margin habitats and the factors affecting their species diversity and composition. The importance of edaphic, spatial and management factors was studied on regional, landscape and habitat scales. Vegetation surveys were conducted on regional and landscape scales and a field experiment on cutting management was conducted on a habitat scale. In field margin plant communities, species appeared to be indicators of high or intermediate soil fertility and moist soil conditions. The plant species diversity found was rather low, compared with most species-rich agricultural habitats in Finland, such as dry meadows. Among regions, land-use history, main production line, natural species and human induced distribution, climate and edaphic factors were elements inducing differences in species composition. The lowest regional species diversity of field margins was related to intensive and long-term cereal production. Management by cutting and removal or grazing had a positive effect on plant species diversity. The positive effect of cutting and removal on species richness was also dependent on the adjacent source of colonizing species. Therefore, in species-poor habitats and landscapes, establishment of margins with diverse seed mixtures can be recommended for enhancing the development of species richness. However, seed mixtures should include only native species preferably local origin. Management by cutting once a year for 5 years did not result in a decline in dominance of a harmful weed species, Elymus repens, showing that E. repens probably needs cutting more frequently than once per year. Agri-environmental schemes should include long-term contracts with farmers for the establishment, and management by cutting and removal or grazing, of field margins that are several metres wide. In such schemes, the timing and frequency of management should be planned so as not to harm other taxa, such as the insects and birds that are dependent on these habitats. All accidental herbicide drifts to field margins should be avoided when spraying the cultivated area to minimize the negative effects of sprayings on vegetation. The harmful effects of herbicides can be avoided by organic farming methods.
  • Jauni, Miia (Helsingin yliopisto, 2012)
    Plant invasions cause a serious threat to native biodiversity. Agricultural habitats are highly disturbed and often invaded by the alien plant species. Generally, the success of a plant invader depends on the abiotic (e.g. climate, habitat properties) and biotic factors (e.g. the characteristics of the invader and interaction with the resident species). In this thesis, I determined the invasion level of alien plant species in Finnish agricultural habitats. In addition, I assessed the environmental conditions and species characteristics affecting plant invasions, and the alien species impact on native species richness and diversity. The invasion level of alien plant species varied between different types of semi-natural agricultural habitats, geographical regions and study years. Generally, more frequently disturbed and more intensively managed habitats (e.g. field and road verges) were more often invaded by alien plants than infrequently disturbed and managed habitats (e.g. grassland). However, the effect of disturbance regime tended to depend on residence time of the alien plant species, and vary among the alien plant species. The invasion level decreased towards north with decreasing temperature and increased towards east with increasing continentality. The geographical trends may be explained by climate, migration history and land-use intensity. In addition, alien plant species diversity increased with higher native plant species diversity. Thus, the results suggest that species interactions, especially competition, with resident plant species do not limit plant invasions in semi-natural agricultural habitats. The positive relationship between native and alien species may be caused by both suitable environmental conditions and spatial heterogeneity in environmental conditions partly created by disturbance of agricultural habitats. The species traits of alien plant species are habitat-specific and strongly related environmental conditions. I did not find evidence that alien plants species cause a severe threat to native plant diversity in Finnish semi-natural habitats. The most harmful invasive plant species are still rare in Finnish agricultural landscape. In the future, the pressure of establishment and spread of alien species can be assumed to increase. Thus, regular monitoring is needed for early detection of new species and detection of the changes in the distribution and the spread of established alien species. The fact that plant invasions are species-specific and depended on environmental characteristics calls for habitat- and species-specific studies on the impacts of alien species and on the determinants of plant invasion at multiple spatial scales.
  • Ma, Maohua (Helsingin yliopisto, 2006)
    Buffer zones are vegetated strip-edges of agricultural fields along watercourses. As linear habitats in agricultural ecosystems, buffer strips dominate and play a leading ecological role in many areas. This thesis focuses on the plant species diversity of the buffer zones in a Finnish agricultural landscape. The main objective of the present study is to identify the determinants of floral species diversity in arable buffer zones from local to regional levels. This study was conducted in a watershed area of a farmland landscape of southern Finland. The study area, Lepsämänjoki, is situated in the Nurmijärvi commune 30 km to the north of Helsinki, Finland. The biotope mosaics were mapped in GIS. A total of 59 buffer zones were surveyed, of which 29 buffer strips surveyed were also sampled by plot. Firstly, two diversity components (species richness and evenness) were investigated to determine whether the relationship between the two is equal and predictable. I found no correlation between species richness and evenness. The relationship between richness and evenness is unpredictable in a small-scale human-shaped ecosystem. Ordination and correlation analyses show that richness and evenness may result from different ecological processes, and thus should be considered separately. Species richness correlated negatively with phosphorus content, and species evenness correlated negatively with the ratio of organic carbon to total nitrogen in soil. The lack of a consistent pattern in the relationship between these two components may be due to site-specific variation in resource utilization by plant species. Within-habitat configuration (width, length, and area) were investigated to determine which is more effective for predicting species richness. More species per unit area increment could be obtained from widening the buffer strip than from lengthening it. The width of the strips is an effective determinant of plant species richness. The increase in species diversity with an increase in the width of buffer strips may be due to cross-sectional habitat gradients within the linear patches. This result can serve as a reference for policy makers, and has application value in agricultural management. In the framework of metacommunity theory, I found that both mass effect(connectivity) and species sorting (resource heterogeneity) were likely to explain species composition and diversity on a local and regional scale. The local and regional processes were interactively dominated by the degree to which dispersal perturbs local communities. In the lowly and intermediately connected regions, species sorting was of primary importance to explain species diversity, while the mass effect surpassed species sorting in the highly connected region. Increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities, and consequently, to lower regional diversity, while local species richness was unrelated to the habitat connectivity. Of all species found, Anthriscus sylvestris, Phalaris arundinacea, and Phleum pretense significantly responded to connectivity, and showed high abundance in the highly connected region. We suggest that these species may play a role in switching the force from local resources to regional connectivity shaping the community structure. On the landscape context level, the different responses of local species richness and evenness to landscape context were investigated. Seven landscape structural parameters served to indicate landscape context on five scales. On all scales but the smallest scales, the Shannon-Wiener diversity of land covers (H') correlated positively with the local richness. The factor (H') showed the highest correlation coefficients in species richness on the second largest scale. The edge density of arable field was the only predictor that correlated with species evenness on all scales, which showed the highest predictive power on the second smallest scale. The different predictive power of the factors on different scales showed a scaledependent relationship between the landscape context and local plant species diversity, and indicated that different ecological processes determine species richness and evenness. The local richness of species depends on a regional process on large scales, which may relate to the regional species pool, while species evenness depends on a fine- or coarse-grained farming system, which may relate to the patch quality of the habitats of field edges near the buffer strips. My results suggested some guidelines of species diversity conservation in the agricultural ecosystem. To maintain a high level of species diversity in the strips, a high level of phosphorus in strip soil should be avoided. Widening the strips is the most effective mean to improve species richness. Habitat connectivity is not always favorable to species diversity because increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities (beta diversity) and, consequently, to lower regional diversity. Overall, a synthesis of local and regional factors emerged as the model that best explain variations in plant species diversity. The studies also suggest that the effects of determinants on species diversity have a complex relationship with scale.
  • Mikkola, Minna (Helsingin yliopisto, 2011)
    The modern food system and sustainable development form a conceptual combination that suggests sustainability deficits in environmental impacts and nutritional status of western populations. This study explores actors orientations towards sustainability by probing into social dynamics for sustainability within primary production and public consumption. If actors within these two worlds were to express converging orientations for sustainability, the system dynamics of the market would enable more sustainable growth in terms of production dictated by consumption. The study is based on a constructivist research approach with qualitative text analyses. The findings were validated by internal and external food system actors and are suggested to represent current social dynamics within Finnish food system. The key findings included primary producers social skilfulness, which enabled networking with other actors in very different paths of life, learning in order to promote one s trade, and trusting reflectively in partners in order to expand business. These activities extended the supply chain in a spiral fashion by horizontal and vertical forward integration, until large retailers were met for negotiations on a more equal basis. This mode of chain level coordination, typically building around the core of social and partnership relations, was coined as a socially overlaid network, and seen as sustainable coordination mode for endogenous growth. The caterers exhibited more or less committed professional identity for sustainability within their reach. The facilitating approaches for professional identities dealt successfully with local and organic food in addition to domestic food, and also imported food. The co-operation with supply chains created innovative solutions and savings for the business parties to be shared. There were also more complicated identities as juggling, critical and delimited approaches for sustainability, with less productive efforts due to restrictions such as absence of organisational sustainability strategy, weak presence of local and organic suppliers, limited understanding about sustainability and no organisational resources for informed choices for sustainability. The convergence between producers and caterers existed to an extent allowing suggestion that increased clarity about sustainable consumption and production by actors could be constructed using advanced tools. The study looks for introduction of more profound environmental and socio-economic knowledge through participatory research with supply chain actors. Learning in the workplace about food system reality in terms of supply chain co-operation may prove to be a change engine that leads to advanced network operations and a more sustainable food system.
  • Ritola, Roosa (Helsingin yliopisto, 2019)
    The aim of this Thesis was to analyze Finnish food policy from a sustainability point of view. Changing operational environment, both globally and nationally, place food systems under a variety of economic, socio-cultural and ecological pressures. In addition to meet the basic objectives, such as ensuring food security, food systems are expected to fulfill a number of other goals. The drivers and goals, as well as means to food system change are defined in food policy. Considering the ecological, economic and sociocultural dimensions of sustainability in the food system analysis can also be viewed as an agroecological approach. A content analysis, using Atlas TI software was done for three most recent and topical Finnish food policy documents: Food2030 - government report on food policy, and the government programs for local and - organic food sectors. The food policy documents were analyzed with the following research questions in mind: how well is the need for systemic change recognized in the Finnish food policy; what are the main drivers for change; how are different dimensions of sustainability taken into account; is the change anticipated as gradual improvements to the current food system or are there any references suggesting radically reformed food system? The recently renewed Finnish food policy is specifically drafted with the current and forecasted changes in the operational environment in mind. The main drivers were mainly identified as sociocultural trends such as globalization, urbanization and changes in consumer behavior. The economic drivers, especially the competitiveness and export orientation of the food sector emerged as important goals for the future. The ecological dimension to food system reform gave the lowest share in all three categories (drivers, means and goals). A change in a complex system such as a food system takes place by affecting one partof the system at a time. The current Finnish food policy does not present radical changes or radical means to change the current system. However system-level changes can often be identified only afterwards.