Suchergebnisse

The combination of tree and pasture production has been recently promoted by the European Union as an agroforestry system type. Pasture production under trees produces annual farm outputs which promote long term rural population stabilisation compared with exclusively forest systems. At the same time, the presence of a tree increases the long term value of the land. The objective of this study was to evaluate the effect of two different tree densities, seed mixtures and fertilization on annual meadow production after 9 years of a silvopastoral system. The tree species was birch (Betula alba L.) established at two densities (2500 and 833 tree ha–1). Fertilization regimes included no fertilization and mineral inputs. Initial seed mixtures included cocksfoot (Dactylis glomerata) and perennial ryegrass (Lolium perenne) together with white and red clover (Trifolium repens and T. pratense). The results showed a significant effect of fertilization, seed mixture and tree density on meadow production. Meadow production was not reduced over time in spite of tree canopy development, which makes birch more suitable for meadow production when compared with radiate pine (Pinus radiata). Fertilization had a major effect at the start of the experiment in terms of modifying annual meadow production. However, by the end of the experiment its effect was modified by tree density and previous seed mixture.

Agroforestry (AF) is the practice of deliberately integrating woody vegetation (trees or shrubs) with crop and/or animal systems to benefit from the resulting ecological and economic interactions. The appropriate application of AF practices is a key avenue to help the European Union to achieve more sustainable methods of food production. However, there is a lack of agroforestry knowledge among end-users. The project AFINET (AgroForestry Innovation NETworks) is a thematic network to foster knowledge exchange between scientists and practitioners on agroforestry. During the initial stage of the project, an assessment of positive (benefits) and negative aspects (limitations) on the implementation of AF systems was conducted among AFINET stakeholders in Galicia (north-west Spain). The reduction of fire risk, the enhancement of biodiversity and the improvement of landscape aesthetics values were perceived as the main benefits of implementing agroforestry by the stakeholders. On the other hand, the possibility of obtaining grants to establish AF systems was perceived as less important. When asked about the limitations, a lack of knowledge and professional advice were identified as the main barriers for the implementation of AF systems in the region, along with the risk of incompatibilities with the common agricultural policy (CAP).

Application of sewage sludge to agricultural soil is a common practice in the European Union (EU) because of low costs and recycling of nutrients achieved. The aim of this study was to evaluate the effects of different types (anaerobic, pelleted and composted sewage sludge) and application rates of sewage sludge on annual pasture production, botanical composition and species richness, compared with an unfertilized control treatment, in meadows established in Galicia (Spain). The results showed that annual pasture production was increased by anaerobic and pelleted sewage sludge in the first year of the study. However, no effects of treatments were found on botanical composition and species richness later in the study.

Sewage sludge use in agriculture is promoted by the European Union since the normative of cleaning waters related to the compulsory use of depuration plants in all cities over 2000 inhabitants was finally implemented in 2005. The University of Santiago de Compostela (USC) has been conducted long-term experiment research about the application of different sewage sludge doses in silvopastoral systems. Main results shown that sewage sludge can be successfully used as fertilizer for both tree and pasture development, with reduced toxicity for animals when plant production is considered in both very acidic and acidic-neutral soils. This paper provides an overview of the main findings in acidic soils of the long-term results after application of sewage sludge in soils.

In the European Union, the majority of afforestation is carried out on former agricultural land. This afforestation causes fundamental changes in ecosystem structure and functioning, with the trees intercepting light and precipitation, producing litterfall and competing for soil nutrients. All of these effects could potentially have a negative impact on understorey biomass and vascular plant biodiversity in a relatively short time span. This study aims to evaluate the effects of afforestation with Pinus radiata D. Don (Monterey pine: pine) and Betula pubescens Ehrh. (Downy birch: birch), established at two different densities (2500 and 833 trees ha21) and sown with two different pasture mixtures (Dactylis glomerata L. + Trifolium repens L. + Trifolium pratense L. and Lolium perenne L. + T. repens L. + T. pratense L.), on understorey biomass, alpha plant biodiversity, life cycle type (annuals vs. perennials) and beta biodiversity over a period of 11 years. Pine showed better development than birch throughout the study, although both species were very sensitive to tree density. While increasing density increased pine height and decreased pine diameter, both aspects of birch development were reduced by higher tree densities. Aboveground biomass increased throughout the study. Alpha plant biodiversity was drastically reduced under pine established at high density, 11 years after afforestation. However, the similarities in species richness, species composition and the low beta growth rates found under pine at low density, and birch at both high and low density suggest that, in these cases, the choice of canopy tree has little consequence for understorey biodiversity at this stage of system development. ; info:eu-repo/semantics/publishedVersion