31 research outputs found
Initial Effects of Differently Treated Biogas Residues from Municipal and Industrial Wastes on Spring Barley Yield Formation
Soil application of biogas residues (BGRs) is important for closing nutrient cycles. This study examined the efficiency and impact on yields and yield formation of solid-liquid separated residues from biodegradable municipal and industrial wastes (bio-waste) in comparison to complete BGRs, nitrification inhibitor, agricultural BGRs, mineral fertilizer and unfertilized plots as control. The experiment was set up as a randomized block design on silt loam Cambisol. Biogas residues from four biogas plants were evaluated. Plants per mÂČ, ears per plant, grains per ear and thousand grain weight (TGW) were measured at harvest. Fertilization with BGRs resulted in similar biomass yields compared with mineral fertilizer. Mineral fertilizer (71 dt/ha) and plots fertilized with liquid fraction (59â62 dt/ha) indicated a trend to higher yields than solid fraction or complete BGR due to its high ammonia content. Liquid fractions and fraction with nitrification inhibitor induced fewer plants per mÂČ than corresponding solid and complete variants due to a potential phytotoxicity of high NH4-N concentration during germination. However, barley on plots fertilized with liquid fraction compensated the disadvantages at the beginning during the vegetation period and induced higher grain yields than solid fraction. This was attributable to a higher number of ears per plant and grains per ear. In conclusion, BGRs from biodegradable municipal and industrial wastes can be used for soil fertilization and replace considerable amounts of mineral fertilizer. Our study showed that direct application of the liquid fraction of BGR is the most suitable strategy to achieve highest grain yields. Nevertheless potential phytotoxicity of the high NH4-N concentration in the liquid fraction should be considered
Nutrient recycling from sanitation and energy systems to the agroecosystem - Ecological research on case studies in Karagwe, Tanzania
Open cycles of organic carbon and nutrients cause soil degradation. Procedures such as ecological sanitation (EcoSan), bioenergy and Terra Preta practice (TPP) can contribute to closing nutrient cycles and may, in addition, sequester carbon. This paper introduces three projects in Karagwe, Tanzania, and their applied approach of integrated resource management to capture carbon and nutrients from different waste flows. Substrates derived from these case studies, biogas slurry, compost and CaSa-compost (containing biochar and sanitized human excreta), were assessed for their nutrient content by analysis of the total element composition. Evaluation focused on potential impacts of the tested amendments on the nutrient availability in the soil as well as on the local soil nutrient balance. Results revealed that all substrates show appropriate fertilizing potential compared to literature, especially for phosphorus (P). CaSa-compost was outstanding, with a total P concentration of 1.7 g dm-3 compared to 0.5 and 0.3 g dm-3 in compost and biogas slurry respectively. Furthermore, these soil amendments may reduce acidity of the soil, with a calculated liming effect of 3.4, 2.6 and 7.8 kg CaO for each kg of nitrogen added for biogas slurry, compost and CaSa-compost respectively. To offset negative P balances in Karagwe, about 8100, 6000 and 1600 dm3 ha-1 are required for biogas slurry, compost and CaSa-compost respectively. We conclude that especially CaSa-compost might offer immediate positive effects to crop production and nutrient availability in the soil
Bodenerosion durch Energiemais â Evaluierung von Erosionsschutzkonzepten mit Erosion-3D
Durch zunehmenden Maisanbau zur Bioenergiegewinnung in Hanglagen erhöht sich die ErosionsgefĂ€hrdung landwirtschaftlicher Böden. Ziel dieser Studie war deshalb die vergleichende Untersuchung von ErosionsschutzmaĂnahmen im Maisanbau unter Verwendung des physikalisch basierten Modells Erosion-3D. Konservierende Bodenbearbeitung (Mulchsaat ohne bzw. mit pflugloser Bodenbearbeitung) zeigte das stĂ€rkste Erosionsminderungspotenzial. Kaum Erosionsminderung konnte durch die Anlage von GrĂŒnstreifen bzw. durch BegrĂŒnung der Abflussrinnen simuliert werden. Eine mittlere Erosionsminderung konnte durch die Unterteilung des Feldes in kleinere Parzellen oder Streifen (abwechselnd Mais- und Wintergetreideanbau) gezeigt werden
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Contrasting effects of biochar on N2O emission and N uptake at different N fertilizer levels on a temperate sandy loam
Biochar has been frequently suggested as an amendment to improve soil quality and mitigate climate change. To investigate the optimal management of nitrogen (N) fertilization, we examined the combined effect of biochar and N fertilizer on plant N uptake and N2O emissions in a cereal rotation system in a randomized two-factorial field experiment on a sandy loam soil in Brandenburg, Germany. The biochar treatment received 10 Mg haâ 1 wood-derived biochar in September 2012. Four levels of N fertilizer, corresponding to 0, 50%, 100%, 130% of the recommended fertilizer level, were applied in winter wheat (Triticum aestivum L.)) and winter rye (Secale cereal L.) in 2013 and 2014 followed by the catch crop oil radish (Raphanus sativus L. var. oleiformis). Biomass and N uptake of winter wheat and winter rye were significantly affected by the level of N fertilizer but not by biochar. For N uptake of oil radish an interaction effect was observed for biochar and N fertilizer. Without applied fertilizer, 39% higher N uptake was found in the presence of biochar, accompanied by higher soil NH4+ content and elevated cumulative CO2 emissions. At 130% of the recommended fertilizer level, 16% lower N uptake and lower cumulative N2O emissions were found in the biochar-mediated treatment. No significant change in abundance of microbial groups and nosZ gene were observed. Our results highlight that biochar can have a greenhouse gas mitigation effect at high levels of N supply and may stimulate nutrient uptake when no N is supplied
Contrasting effects of biochar on N2O emission and N uptake at different N fertilizer levels on a temperate sandy loam
Biochar has been frequently suggested as an amendment to improve soil quality and mitigate climate change. To investigate the optimal management of nitrogen (N) fertilization, we examined the combined effect of biochar and N fertilizer on plant N uptake and N2O emissions in a cereal rotation system in a randomized two-factorial field experiment on a sandy loam soil in Brandenburg, Germany. The biochar treatment received 10 Mg haâ 1 wood-derived biochar in September 2012. Four levels of N fertilizer, corresponding to 0, 50%, 100%, 130% of the recommended fertilizer level, were applied in winter wheat (Triticum aestivum L.)) and winter rye (Secale cereal L.) in 2013 and 2014 followed by the catch crop oil radish (Raphanus sativus L. var. oleiformis). Biomass and N uptake of winter wheat and winter rye were significantly affected by the level of N fertilizer but not by biochar. For N uptake of oil radish an interaction effect was observed for biochar and N fertilizer. Without applied fertilizer, 39% higher N uptake was found in the presence of biochar, accompanied by higher soil NH4+ content and elevated cumulative CO2 emissions. At 130% of the recommended fertilizer level, 16% lower N uptake and lower cumulative N2O emissions were found in the biochar-mediated treatment. No significant change in abundance of microbial groups and nosZ gene were observed. Our results highlight that biochar can have a greenhouse gas mitigation effect at high levels of N supply and may stimulate nutrient uptake when no N is supplied
Environmental Effects over the First 2 1/2 Rotation Periods of a Fertilised Poplar Short Rotation Coppice
A short rotation coppice (SRC) with poplar was established in a randomised
fertilisation experiment on sandy loam soil in Potsdam (Northeast Germany).
The main objective of this study was to assess if negative environmental
effects as nitrogen leaching and greenhouse gas emissions are enhanced by
mineral nitrogen (N) fertiliser applied to poplar at rates of 0, 50 and 75 kg
N haâ1 yearâ1 and how these effects are influenced by tree age with increasing
number of rotation periods and cycles of organic matter decomposition and tree
growth after each harvesting event. Between 2008 and 2012, the leaching of
nitrate (NO3 â) was monitored with self-integrating accumulators over 6-month
periods and the emissions of the greenhouse gases (GHG) nitrous oxide (N2O)
and carbon dioxide (CO2) were determined in closed gas chambers. During the
first 4 years of the poplar SRC, most nitrogen was lost through NO3 â leaching
from the main root zone; however, there was no significant relationship to the
rate of N fertilisation. On average, 5.8 kg N haâ1 yearâ1 (13.0 kg CO2equ) was
leached from the root zone. Nitrogen leaching rates decreased in the course of
the 4-year study parallel to an increase of the fine root biomass and the
degree of mycorrhization. In contrast to N leaching, the loss of nitrogen by
N2O emissions from the soil was very low with an average of 0.61 kg N haâ1
yearâ1 (182 kg CO2equ) and were also not affected by N fertilisation over the
whole study period. Real CO2 emissions from the poplar soil were two orders of
magnitude higher ranging between 15,122 and 19,091 kg CO2 haâ1 yearâ1 and
followed the rotation period with enhanced emission rates in the years of
harvest. As key-factors for NO3 â leaching and N2O emissions, the time after
planting and after harvest and the rotation period have been identified by a
mixed effects model
Biochar application to sandy soil: effects of different biochars and N fertilization on crop yields in a three-year field experiment
Einfluss pyrogener Kohle auf den Stoffhaushalt tropischer Böden in Mosambik
Die Einarbeitung von pyrogener Kohle in Verbindung mit organischem DĂŒnger in nĂ€hrstoffarme tropische Böden birgt ein Potenzial zur Ertragsteigerung in der Landwirtschaft. In einem zweimonatigen Parzellenversuch auf einer Jatropha-Plantage in Zentral Mosambik wurde der Einfluss von Biokohle und Grasschnitt auf den NĂ€hrstoffhaushalt zweier Böden, die sich deutlich in Ton- und C-Gehalt unterscheiden, getestet: Ein sandiger, C-Ă€rmerer Stagnosol und ein lehmiger C reicherer Luvisol. Auf dem Stagnosol wurde eine deutliche Verbesserung der P- und K-VerfĂŒgbarkeit im Boden, eine Erhöhung des pH-Wertes und eine Steigerung der Jatropha-Blattgehalte an P, K, Mg, N und S erreicht, allerdings noch keine Ertragssteigerung. Auf dem bereits fruchtbaren lehmigen Luvisol war die Biokohle Zugabe dort nicht lohnenswert Aufgrund des höheren Ton- und C-Gehalts gab es nur geringe Effekte. FĂŒr nĂ€hrstoffarme, sandige Böden bleibt eine lĂ€ngerfristige, nachhaltige Wirkung der Biokohle-Effekte zu prĂŒfen
Sustainable and resource efficient intensivation of crop production â Perspectives of agro-ecosystem researchPolicy paper of the DFG Senate Commission on Agroecosystem Research
Mit dem vorliegenden Grundsatzpapier zeigt die Senatskommission fĂŒr Agrarökosystemforschung Perspektiven fĂŒr die Grundlagenforschung zur nachhaltigen Erhöhung der Kulturpflanzenproduktion auf.Agrarsysteme stehen im Spannungsfeld zwischen steigendem Bedarf an landwirtschaftlichen Produkten, der Verknappung der Ressourcen, dem Verlust der BiodiversitĂ€t und dem Klimawandel. Die fĂŒr das Jahr 2050 prognostizierte notwendige Ertragssteigerung zur Sicherstellung des Bedarfs an Nahrungsmitteln kann, ohne die Belastbarkeitsgrenzen ökologischer Systeme zu ĂŒberschreiten, nur durch wissenschaftlichen Fortschritt bewĂ€ltigt werden (Abb. 1), der eine nachhaltige und ressourcenÂeffiziente Steigerung der Agrarproduktion ermöglicht (FAO, 2011; Dobermann und Nelson, 2013). Die nachhaltige Intensivierung stellt die Agrarwissenschaften vor neue Aufgaben, die weit ĂŒber ihre klassischen Grenzen hinausgehen.Die Senatskommission plĂ€diert daher fĂŒr eine Erweiterung der agrarwissenschaftlichen Perspektive. Die meist auf einzelne FeldfrĂŒchte bezogene Bewertung der RelaÂtion zwischen Input und Ertrag muss ergĂ€nzt werden um die Optionen, die sich aus der rĂ€umlichen und zeitlichen Diversifikation der Produktionssysteme unter Einbeziehung der standörtlichen Eigenschaften, des Landschaftskontextes sowie des Klimawandels ergeben. Um Ăkosystemleistungen einzubeziehen, mĂŒssen Produktionsstrategien entwickelt werden, die sich auf ganze Landschaften und Regionen richten und auch entsprechende sozioÂökoÂnoÂmische und agrarpolitische Rahmenbedingungen berĂŒcksichtigen.Vor diesem Hintergrund schlĂ€gt die Senatskommission drei interdisziplinĂ€re Forschungsschwerpunkte zur ressourceneffizienten Erhöhung der FlĂ€chenproduktivitĂ€t vor:(1) Ausnutzung des Potentials von Kulturpflanzen zur umweltschonenden Ertragssteigerung im Kontext ökoÂsystemarer Bedingungen.(2) Nachhaltige Steigerung der Pflanzenproduktion im Landschaftskontext.(3) Ăkonomische, gesellschaftliche und politische Dimensionen der Ertragssteigerung von Kulturpflanzen. DOI: 10.5073/JfK.2014.07.01, https://doi.org/10.5073/JfK.2014.07.01With its policy paper the Senate Commission on Agro-ecosystem Research of the Deutsche Forschungsgemeinschaft (DFG) summarizes potential benefits of basic research for the sustainable intensification of crop production. Agro-ecosystems critically contribute to fulfilling the need for increasing food and fiber production, diminishing resource depletion as well as counteracting biodiversity loss and climate change. Yield demands that are needed to ensure the food supply predicted for the year 2050 can only be achieved by scientific progress that allows the intensive yet environmentally friendly production of plant biomass (Figure 1), (FAO, 2011; Dobermann und Nelson, 2013; Ray et al., 2013). Sustainable intensification requires a scientific realignment that allows for broadening the scope of agricultural research. The productivity of farming systems should be evaluated with regard to their efficiency (input-output relation). In addition, the spatial and temporal variability of these systems must be considered by addressing local conditions, the landscape context and climate change. With respect to ecosystem services, new production strategies must be developed that take all aspects of landscape and regional complexity as well as socio-economic conditions and agricultural policy into account.Against this background, the Senate Commission on Agro-ecosystem Research proposes three priority areas of interdisciplinary research on resource efficient intensification of crop production:(1) Exploiting the biological potential of the individual crop plants for an environmentally friendly intensification in an ecosystem approach(2) Exploring sustainable intensification of crop production within a landscape context(3) Taking full account of the economic, social and political dimensions of sustainable intensification of crop production DOI: 10.5073/JfK.2014.07.01, https://doi.org/10.5073/JfK.2014.07.0
Global concentrations of microplastics in soils â a review
Worldwide, microplastics (MPs) have been commonly recognized as a threat to soil ecosystems. Terrestrial soils are widely contaminated by MPs due to the application of sewage sludge and wastewater, plastic mulching, littering, the input of tire wear from roads and atmospheric deposition. Within the last decade, an increasing number of individual studies focused on item counts and masses of MPs in different global soil environments.
We reviewed these studies to achieve a representative picture of common degrees of contamination. The majority of the prospected agricultural and horticultural sites were exposed to sewage sludge and mulching film application and showed concentrations of <13â000âitemsâkgâ1 dry soil and 4.5âmgâkgâ1 dry soil. Microplastic concentrations in soils in the vicinity of municipal areas were thereby 10 times larger compared to rural sites. The measurement of masses was generally underrepresented compared to item numbers, and mass data were often generated from microscopic analyses by using shape-to-mass models instead of direct measurements. Extreme values, such as on industrial sites, exceed the common concentrations by 2 to 4 orders of magnitude, which might be attributed not only to the land use but also to the applied methods of measurement. Campaigns that focus on other entry pathways like composts, road dust runoff and littering or land uses like grassland, forest, fallow and wilderness as well as industrial sites and landfills were underrepresented or nonexistent. Background loads, such as atmospheric deposition, were often not excluded from the measurements and, thus, the studies might overestimate the contribution of the analyzed entry pathway to the total load. Other studies focused on light density MP, e.g., from mulching films, and therefore underestimated the amount of soil MP.
Despite these limitations, the data give an impression of the spectrum of global MP concentrations and are a good basis for experiments examining the effects of MPs on exposed soils. Based on the collected data, we identified problems of past studies and recommend that future experimentation take into account standardized methods of extraction and quantification, a proper characterization of the sampling sites and their history as well as the exploration of as yet underrepresented entry pathways and land uses.TU Berlin, Open-Access-Mittel â 202