Impact of agricultural management on soil aggregates and associated organic carbon fractions: analysis of long-term experiments in Europe

Inversion tillage is a commonly applied soil cultivation practice in Europe, which often has been blamed for deteriorating topsoil stability and organic carbon (OC) content. In this study, the potential to reverse these negative effects in the topsoil by alternative agricultural management practices are evaluated in seven long-term experiments (running from 8 to 54 years the moment of sampling) in five European countries (Belgium, Czech Republic, Hungary, Italy and UK). Topsoil samples (0–15 cm) were collected and analysed to evaluate the effects of conservation tillage (reduced and no tillage) and increased organic inputs of different origin (farmyard manure, compost, crop residues) combined with inversion tillage on topsoil stability, soil aggregates and, within these, OC distribution using wet sieving after slaking. Effects from the treatments on the two main components of organic matter, i.e. particulate (POM) and mineral associated (MAOM), were also evaluated using dispersion and size fractionation. Reduced and no-tillage practices, as well as the additions of manure or compost, increased the aggregates mean weight diameter (MWD) (up to 49 % at the Belgian study site) and topsoil OC (up to 51 % at the Belgian study site), as well as the OC corresponding to the different aggregate size fractions. The incorporation of crop residues had a positive impact on the MWD but a less profound effect both on total OC and on OC associated with the different aggregates. A negative relationship between the mass and the OC content of the microaggregates (53–250 µm) was identified in all experiments. There was no effect on the mass of the macroaggregates and the occluded microaggregates (mM) within these macroaggregates, while the corresponding OC contents increased with less tillage and more organic inputs. Inversion tillage led to less POM within the mM, whereas the different organic inputs did not affect it. In all experiments where the total POM increased, the total soil organic carbon (SOC) was also affected positively. We concluded that the negative effects of inversion tillage on topsoil can be mitigated by reducing the tillage intensity or adding organic materials, optimally combined with non-inversion tillage methods.</p

Opportunities for Mitigating Soil Compaction in Europe-Case Studies from the SoilCare Project Using Soil-Improving Cropping Systems

Soil compaction (SC) is a major threat for agriculture in Europe that affects many ecosystem functions, such as water and air circulation in soils, root growth, and crop production. Our objective was to present the results from five short-term (25 cm) compaction using subsoiling tillage treatments to depths of 35 cm (Sweden) and 60 cm (Romania). The other SSs addressed both topsoil and subsoil SC (>25 cm, Norway and United Kingdom; >30 cm, Italy) using deep-rooted bio-drilling crops and different tillage types or a combination of both. Each SS evaluated the effectiveness of the SICSs by measuring the soil physical properties, and we calculated SC indices. The SICSs showed promising results-for example, alfalfa in Norway showed good potential for alleviating SC (the subsoil density decreased from 1.69 to 1.45 g cm(-1)) and subsoiling at the Swedish SS improved root penetration into the subsoil by about 10 cm-but the effects of SICSs on yields were generally small. These case studies also reflected difficulties in implementing SICSs, some of which are under development, and we discuss methodological issues for measuring their effectiveness. There is a need for refining these SICSs and for evaluating their longer-term effect under a wider range of pedoclimatic conditions

Soil-Improving Cropping Systems for Sustainable and Profitable Farming in Europe

Soils form the basis for agricultural production and other ecosystem services, and soil management should aim at improving their quality and resilience. Within the SoilCare project, the concept of soil-improving cropping systems (SICS) was developed as a holistic approach to facilitate the adoption of soil management that is sustainable and profitable. SICS selected with stakeholders were monitored and evaluated for environmental, sociocultural, and economic effects to determine profitability and sustainability. Monitoring results were upscaled to European level using modelling and Europe-wide data, and a mapping tool was developed to assist in selection of appropriate SICS across Europe. Furthermore, biophysical, sociocultural, economic, and policy reasons for (non)adoption were studied. Results at the plot/farm scale showed a small positive impact of SICS on environment and soil, no effect on sustainability, and small negative impacts on economic and sociocultural dimensions. Modelling showed that different SICS had different impacts across Europe-indicating the importance of understanding local dynamics in Europe-wide assessments. Work on adoption of SICS confirmed the role economic considerations play in the uptake of SICS, but also highlighted social factors such as trust. The project's results underlined the need for policies that support and enable a transition to more sustainable agricultural practices in a coherent way

Soil-Improving Cropping Systems for Sustainable and Profitable Farming in Europe

Soils form the basis for agricultural production and other ecosystem services, and soil management should aim at improving their quality and resilience. Within the SoilCare project, the concept of soil-improving cropping systems (SICS) was developed as a holistic approach to facilitate the adoption of soil management that is sustainable and profitable. SICS selected with stakeholders were monitored and evaluated for environmental, sociocultural, and economic effects to determine profitability and sustainability. Monitoring results were upscaled to European level using modelling and Europe-wide data, and a mapping tool was developed to assist in selection of appropriate SICS across Europe. Furthermore, biophysical, sociocultural, economic, and policy reasons for (non)adoption were studied. Results at the plot/farm scale showed a small positive impact of SICS on environment and soil, no effect on sustainability, and small negative impacts on economic and sociocultural dimensions. Modelling showed that different SICS had different impacts across Europe—indicating the importance of understanding local dynamics in Europe-wide assessments. Work on adoption of SICS confirmed the role economic considerations play in the uptake of SICS, but also highlighted social factors such as trust. The project’s results underlined the need for policies that support and enable a transition to more sustainable agricultural practices in a coherent way

Soil Water Retention as Affected by Management Induced Changes of Soil Organic Carbon: Analysis of Long-Term Experiments in Europe

Soil water retention (SWR) is an important soil property related to soil structure, texture, and organic matter (SOM), among other properties. Agricultural management practices affect some of these properties in an interdependent way. In this study, the impact of management-induced changes of soil organic carbon (SOC) on SWR is evaluated in five long-term experiments in Europe (running from 8 up to 54 years when samples were taken). Topsoil samples (0&ndash;15 cm) were collected and analysed to evaluate the effects of three different management categories, i.e., soil tillage, the addition of exogenous organic materials, the incorporation of crop residues affecting SOC and water content under a range of matric potentials. Changes in the total SOC up to 10 g C kg&minus;1 soil (1%) observed for the different management practices, do not cause statistically significant differences in the SWR characteristics as expected. The direct impact of the SOC on SWR is consistent but negligible, whereas the indirect impact of SOC in the higher matric potentials, which are mainly affected by soil structure and aggregate composition, prevails. The different water content responses under the various matric potentials to SOC changes for each management group implies that one conservation measure alone has a limited effect on SWR and only a combination of several practices that lead to better soil structure, such as reduced soil disturbances combined with increased SOM inputs can lead to better water holding capacity of the soil

Report on demonstration activities in the study sites

Executive summary The SoilCare project aims at developing soil improving cropping systems. At 16 study sites dispersed over Europe experiments have been implemented. These were selected in collaboration with the stakeholders (WP3) and based on a literature review (WP2). The methodology for monitoring the experiments was compiled by WP4. The results are being compiled by WP5. In addition, all study sites had to organize demonstration activities and field days of the selected cropping systems. The combined findings by the study sites are an important input for the upscaling by WP6, the policy analysis by WP7 and the dissemination by WP8. The demonstrations/field days for the stakeholders are an important tool for sharing experiences between the stakeholders and the researchers while inspecting and reflecting over the experiments in the field. A total of 31 demonstration events/field days took place in the 16 study sites over two years. Four out of the sixteen study sites organised three or more. Six out of the sixteen study sites organised two demonstration/field days and six organised one. In total, about 937 stakeholders attended the demonstration events. The average number of participants in the events was 30. The demonstration/field days are experienced by the stakeholders and researchers of the study sites as a very useful activity in combination with a more systematic consultation with the stakeholders. The specific feedback by each study site is given in a table and can be found in more detail in the reports by the study sites in appendix I. Several points were discussed in different degrees: the need for machinery, the incentives by subsidies, the selection of crops, rotations and cover crops, the erodibility and the soil structure/quality. Also many participants stressed the need for communication and information on soil improving cropping systems. A major general concern for all stakeholders was the economic performance of the cropping systems. Also, weed infestation and weed control management was also a recurring theme.status: Published onlin

Evaluation of soil salinity amelioration technologies in Timpaki, Crete

Salinization is a soil threat that adversely affects ecosystem services and diminishes soil functions in many arid and semi-arid regions. Soil salinity management depends on a range of factors, and can be complex expensive and time demanding. Besides taking no action, possible management strategies include amelioration and adaptation measures. The WOCAT Technologies Questionnaire is a standardized methodology for monitoring, evaluating and documenting sustainable land management practices through interaction with the stakeholders. Here we use WOCAT for the systematic analysis and evaluation of soil salinization amelioration measures, for the RECARE project Case Study in Greece, the Timpaki basin, a semi-arid region in south-central Crete where the main land use is horticulture in greenhouses irrigated by groundwater. Excessive groundwater abstractions have resulted in a drop of the groundwater level in the coastal part of the aquifer, thus leading to seawater intrusion and in turn to soil salinization due to irrigation with brackish water. Amelioration technologies that have already been applied in the case study by the stakeholders are examined and classified depending on the function they promote and/or improve. The documented technologies are evaluated for their impacts on ecosystem services, cost and input requirements. Preliminary results show that technologies which promote maintaining existing crop types while enhancing productivity and decreasing soil salinity such as composting, mulching, rain water harvesting and seed biopriming are preferred by the stakeholders. Further work will include result validation using qualitative approaches

Climate Change Impact on Photovoltaic Energy Output: The Case of Greece

Solar power is the third major renewable energy, constituting an increasingly important component of global future—low carbon—energy portfolio. Accurate climate information is essential for the conditions of solar energy production, maximization, and stable regulation and planning. Climate change impacts on energy output projections are thus of crucial importance. In this study the effect of projected changes in irradiance and temperature on the performance of photovoltaic systems in Greece is examined. Climate projections were obtained from 5 regional climate models (RCMs) under the A1B emissions scenario, for two future periods. The RCM data present systematic errors against observed values, resulting in the need of bias adjustment. The projected change in photovoltaic energy output was then estimated, considering changes in temperature and insolation. The spatiotemporal analysis indicates significant increase in mean annual temperature (up to 3.5°C) and mean total radiation (up to 5 W/m2) by 2100. The performance of photovoltaic systems exhibits a negative linear dependence on the projected temperature increase which is outweighed by the expected increase of total radiation resulting in an up to 4% increase in energy output

Impact of drought in the mediterranean pasturelands under the effect of climate change

Μεταπτυχιακή διατριβή για την εκπλήρωση των υποχρεώσεων του μεταπτυχιακού διπλώματος ειδίκευσης της σχολής μηχανικών περιβάλλοντοςΠερίληψη: Η μελέτη των επιπτώσεων της κλιματικής αλλαγής στις άνυδρες περιοχές όπως η Μεσόγειος αποτελεί σημαντικό αντικείμενο έρευνας τα τελευταία χρόνια καθώς είναι εξαιρετικά απρόβλεπτες και επηρεάζονται από ακραία καιρικά φαινόμενα όπως η ξηρασία. Η αύξηση της μέσης θερμοκρασίας και η μεταβλητότητα των βροχοπτώσεων αναμένεται να επηρεάσει την διακύμανση της ξηρασίας και κατά συνέπεια την παραγωγικότητα των οικοσυστημάτων. Η πρόβλεψη της απόκρισης της βλάστησης στις ξηρασίες μπορεί να βοηθήσει στη δημιουργία στρατηγικών και λήψη αποφάσεων για όλους τους εμπλεκόμενους φορείς. Στην παρούσα εργασία χρησιμοποιούνται εννέα διαφορετικά κλιματικά μοντέλα πρόβλεψης κάτω από δύο σενάρια συγκεντρώσεων αερίων του θερμοκηπίου. Λόγω των συστηματικών σφαλμάτων που παρουσιάζουν τα κλιματικά μοντέλα, ακολουθεί διόρθωση του σφάλματος μεροληψίας για περιορισμό των υπαρχόντων αβεβαιοτήτων. Με βάση τα παραπάνω γίνεται (α) πρόβλεψη της διακύμανσης της ξηρασίας με τους δείκτες ξηρασίας SPI, που λαμβάνει υπόψη μόνο την βροχόπτωση, και RDI, που συνυπολογίζει και την αλλαγή της θερμοκρασίας, και (β) πρόβλεψη των φαινομένων ξηρότητας με χρήση του δείκτη ξηρότητας της UNEP. Η σχετική αλλαγή της απόκρισης της βλάστησης των βοσκοτόπων στην αλλαγή του κλίματος υπολογίζεται με την συνάρτηση καλλιέργειας–ύδατος παραγωγής όπου προτείνεται από το FAO. Η ανάλυση των αποτελεσμάτων γίνεται για 2 μελλοντικές περιόδους μελέτης στην ευρωπαϊκή περιοχή της Μεσογείου καθώς και 4 περιοχές ενδιαφέροντος του ευρωπαϊκού προγράμματος CASCADE που υπόκεινται σε διαφορετικούς βαθμούς κτηνοτροφικής εκμετάλλευσης. Έπειτα από την χωρική ανάλυση παρατηρήθηκε ότι στο μέλλον, τα φαινόμενα ξηρασίας σταδιακά αυξάνονται τόσο σε ένταση και δριμύτητα αλλά και σε χωρική έκταση με τις περισσότερες περιοχές της Μεσογείου να μεταβαίνον τουλάχιστον σε μία πιο ξηρή κλάση κατηγοριοποίησης. Αυτό έχει ως αντίκτυπο τη μείωση της σχετικής απόδοσης της βλάστησης των βοσκοτόπων μέχρι και 100%, σε μεμονωμένες βέβαια περιοχές, καθιστώντας τους εντελώς μη παραγωγικούς. Αντίθετα, παρατηρείται αύξηση της απόδοσης σε περιοχές όπου υπάρχουν ορεινοί όγκοι και σήμερα χαρακτηρίζονται πιο υγρές. Τα μοντέλα παρουσιάζουν παρόμοια αποτελέσματα μέχρι το 2050, με την αβεβαιότητα να αυξάνεται ως το 2100, και με την αύξηση του γεωγραφικού πλάτους. Η χρονική ανάλυση στις περιοχές ενδιαφέροντος καταδεικνύει τάση για αύξηση της θερμοκρασίας, της εξατμισοδιαπνοής, της ξηρότητας και έντασης των φαινομένων ξηρασίας, ενώ αντίθετα μείωση των κατακρημνίσεων.Summarization: The study of climate change effects on drylands, like the Mediterranean, constitutes an important research field the last decades, due to their remarkably unpredictable character and their influence from extreme events such as drought. The increase of mean temperature, as well as the precipitation variability is predicted to affect the fluctuation of drought and consequently the productivity of ecosystems. The projection of yield response to droughts may be especially useful, by providing sustainable solutions through the creation of strategies and decisions making for the stakeholders. In this work, climate model data is obtained from 9 GCMs under two greenhouse gas concentration trajectories, RCP2.6 and RCP8.5 of the 5th phase of the Coupled Model Intercomparison Project, and corrected for biases. The derived dataset is used for the projection of the fluctuation of drought, using two drought indices, SPI and RDI. The former only takes into account precipitation while the latter takes also considers the change in temperature. For the prediction of aridity, the UNEP aridity index (〖AI〗_U) from Precipitation (P) and Potential Evapotranspiration (PET), is used. The relative yield response of the pasturelands to climate change is estimated by the crop-water production function proposed by FAO. Results are analyzed for two future study periods, within a domain that includes the entire European Mediterranean and four CASCADE FP7 Project Study Sites. A gradual increase in the intensity and severity of the drought events, as well as in their spatial extend is observed, with the majority of the Mediterranean areas to drop at least one class in the aridity gradient. This reflects on the grazing lands yield, as a reduction in the relative yield response up to 100% in individual regions, which may render them totally unproductive for the current species. On the other hand, an increase of yield is observed in mountainous areas which are currently characterized wet. The models projections show similar results up to 2050. However, uncertainty increases from then until 2100 and with the increase of latitude. The temporal analysis in the four study areas indicates an increasing trend in temperature, evapotranspiration, aridity and intensity of drought events, while precipitation shows a decreasing trend