Examinando por Autor "Borchard, N."
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Ítem Acceso Abierto Application of biochars to sandy and silty soil failed to increase maize yield under common agricultural practice(Elsevier, 2014) Borchard, N.; Siemens, J.; Ladd, B.; Möller, A.; Amelung, W.Adding biochar to tropical soils is a strategy for improving crop yield and mitigating climate change, but how various biochar types affect crop yield and the properties of temperate soils is still in dispute. Here, we evaluated how slow-pyrolysis charcoal and two biochars derived from energy production (gasification coke and flash-pyrolysis char) affected the growth of Zea mays L. and the related properties of sandy and silty soils within a 3-year mesocosm experiment. Fertilization was performed to optimize plant growth as would be done under common agricultural practice. Analyses included the monitoring of yield, plant and soil nutrients, aggregate stability, cation exchange and water holding capacity, and black carbon content. The results showed that the added biochars did not affect crop yield at an application rate of 15gbiocharkg-1 of soil. Increasing the application rate of slow-pyrolysis charcoal to 100gkg-1 resulted in decreased plant biomass in the second and third year of the experiment, likely as a result of nutrient imbalances and N-immobilization. We did not detect any degradation of the added black carbon; however, beneficial effects on plants were limited by the small and transient effect of these biochars on the physical and chemical properties of soil. Overall, our results indicate that the added carbon from biochars is stored in soil, but all treatments tested failed to improve plant yield for the studied temperate soils under the given application rates and common agricultural practice. © 2014 Elsevier B.V.Ítem Acceso Abierto Biochar research activities and their relation to development and environmental quality. A meta-analysis(Springer-Verlag France, 2017) Mehmood, K.; Chávez Garcia, E.; Schirrmann, M.; Ladd, B.; Kammann, C.; Wrage-Mönnig, N.; Siebe, C.; Estavillo, J.M.; Fuertes-Mendizabal, T.; Cayuela, M.; Sigua, G.; Spokas, K.; Cowie, A.L.; Novak, J.; Ippolito, J.A.; Borchard, N.Biochar is the solid product that results from pyrolysis of organic materials. Its addition to highly weathered soils changes physico-chemical soil properties, improves soil functions and enhances crop yields. Highly weathered soils are typical of humid tropics where agricultural productivity is low and needs to be raised to reduce human hunger and poverty. However, impact of biochar research on scientists, politicians and end-users in poor tropical countries remains unknown; assessing needs and interests on biochar is essential to develop reliable knowledge transfer/translation mechanisms. The aim of this publication is to present results of a meta-analysis conducted to (1) survey global biochar research published between 2010 and 2014 to assess its relation to human development and environmental quality, and (2) deduce, based on the results of this analysis, priorities required to assess and promote the role of biochar in the development of adapted and sustainable agronomic methods. Our main findings reveal for the very first time that: (1) biochar research associated with less developed countries focused on biochar production technologies (26.5 ± 0.7%), then on biochars’ impact on chemical soil properties (18.7 ± 1.2%), and on plant productivity (17.1 ± 2.6%); (2) China dominated biochar research activities among the medium developed countries focusing on biochar production technologies (26.8 ± 0.5%) and on use of biochar as sorbent for organic and inorganic compounds (29.1 ± 0.4%); and (3) the majority of biochar research (69.0±2.9%) was associated with highly developed countries that are able to address a higher diversity of questions. Evidently, less developed countries are eager to improve soil fertility and agricultural productivity, which requires transfer and/or translation of biochar knowledge acquired in highly developed countries. Yet, improving local research capacities and encouraging synergies across scientific disciplines and countries are crucial to foster development of sustainable agronomy in less developed countries. © 2017, The Author(s).Ítem Acceso Abierto Black carbon and soil properties at historical charcoal production sites in Germany(Elsevier, 2014) Borchard, N.; Ladd, B.; Eschemann, S.; Hegenberg, D.; Möseler, B.M.; Amelung, W.The use of charcoal as a soil amendment is currently of great interest to sequester carbon and improve soil fertility, however, studies of sites where charcoal amendments to the soil have been made many years ago are lacking at the moment. In this study we investigated historical charcoal production sites in Germany that have not been in use for >60years, and evaluated the effects of the former charcoal inputs on soil and vegetation parameters relative to those of adjacent, unamended areas. Surface soil samples (0-5, 5-20cm) were taken from five sites located on extremely acidic (Siegerland, pH3.8-4.1) and base rich soils (Eifel, pH4.8-5.3) in species poor (Luzulo-Fagetum) and species rich (Hordelymo-Fagetum) beech forests, respectively. We determined stocks of black carbon (BC) and natural soil organic carbon (SOC=total C minus BC) as well as of soil nutrient stocks (NO3-N, P, K, Mg), cation exchange capacity and water holding capacity, and we mapped plant composition to calculate richness and evenness. The results showed that historical charcoal production sites were enriched with BC and also exhibited increased stocks of natural SOC and total N possibly due to enhanced stabilization of natural SOC by the charcoal. The availability of nitrate-nitrogen, phosphate and potassium was increased when the charcoal was added to the base rich soils and less so when charcoal was added to the extremely acidic soils. Plant biodiversity was not different between the sites of historical charcoal addition and the reference sites. We conclude that charcoal additions may increase soil carbon storage capacity over prolonged periods of time without negatively affecting plant ecological interactions over the long term. © 2014 Elsevier B.V.Ítem Acceso Abierto Carbon accrual rates, vegetation and nutrient dynamics in a regularly burned coppice woodland in Germany(Blackwell Publishing Ltd, 2017) Borchard, N.; Adolphs, T.; Beulshausen, F.; Ladd, B.; Gießelmann, U.C.; Hegenberg, D.; Möseler, B.M.; Amelung, W.Historically, large areas of forest in Europe were managed as coppice woodland to produce wood-based fuel for the smelting industry. We hypothesized that this practice produced a legacy effect on current forest ecosystem properties. Specifically, we hypothesized that the historical form of coppicing may have produced a legacy of elevated stocks of soil organic carbon (SOC), nutrients and black carbon (BC) in soil as fire was routinely used in coppiced woodland to clear land. We further hypothesized that these changes in soil properties would result in increased biodiversity. To test these hypotheses, we sampled the surface soil (0–5, 5–10 and 10–20 cm) from a chronosequence of forest sites found in the Siegerland (Germany) that had been coppiced and burned 1, 2, 3.5, 6, 8, 11 and 17 years before present. Mature beech and spruce forests (i.e., >60 years) were also sampled as reference sites: to provide a hint of what might occur in the absence of human intervention. We measured stocks of SOC, BC, NO3-N, P, K, Mg, as well as cation exchange and water-holding capacity, and we mapped plant composition to calculate species richness and evenness. The results showed that coppicing in combination with burning soil and litter improved soil nutrient availability, enhanced biodiversity and increased SOC stocks. The SOC stocks and biodiversity were increased by a factor of three relative to those in the mature beech and spruce forests. This study shows that traditional coppicing practice may facilitate net C accrual rates of 20 t ha−1 yr−1 and maintain high biodiversity, indicating that aspects of traditional practice could be applied in current forest management to foster biodiversity and to mitigate climate change. © 2016 The Authors Global Change Biology Bioenergy Published by John Wiley & Sons Ltd.Ítem Acceso Abierto Carbon storage in a high-altitude Polylepis woodland in the Peruvian Andes(Birkhauser Verlag AG, 2014) Vásquez, E.; Ladd, B.; Borchard, N.Polylepis woodland occurs in Peru's tropical highlands at elevations between 3,500 and 5,000 m above sea level and Polylepis is the most common tree at timberline in South America. The objective of this study was to assess the total ecosystem carbon stock in a Polylepis incana woodland, i.e., aboveground biomass (canopy trees and understory), root biomass and soil carbon stocks were all quantified. As part of this study, an allometric equation for the quantification of the aboveground biomass of individual P. incana trees was developed for the first time. The most important carbon pool was the soil (39.7 ± 6.9 kg m-2) followed by the aboveground biomass of Polylepis trees (3.8 ± 0.7 kg m-2). The total ecosystem carbon stock was estimated to be 43.9 ± 7.6 kg m-2; thus, 90.6 % of the ecosystem carbon stock is soil carbon. © 2014 Swiss Botanical Society.Ítem Acceso Abierto On the use of hedonic price indices to understand ecosystem service provision from urban green space in five Latin American megacities(MDPI AG, 2017) de Mola, U.L.; Ladd, B.; Duarte, S.; Borchard, N.; La Rosa, R.A.; Zutta, B.Latin American (LA) megacities are facing enormous challenges to provide welfare to millions of people who live in them. High rates of urbanization and limited administrative capacity of LA cities to plan and control urban growth have led to a critical deficit of urban green space, and therefore, to sub-optimal outcomes in terms of urban sustainability. This study seeks to assess the possibility of using real estate prices to provide an estimate of the monetary value of the ecosystem services provided by urban green space across five Latin American megacities: Bogota, Buenos Aires, Lima, Mexico City and Santiago de Chile. Using Google Earth images to quantify urban green space and multiple regression analysis, we evaluated the impact of urban green space, crime rates, business density and population density on real estate prices across the five mentioned megacities. In addition, for a subset of the data (Lima and Buenos Aires) we analyzed the effects of landscape ecology variables (green space patch size, connectivity, etc.) on real estate prices to provide a first insight into how the ecological attributes of urban green space can determine the level of ecosystem service provision in different urban contexts in Latin America. The results show a strong positive relationship between the presence of urban green space and real estate prices. Green space explains 52% of the variability in real estate prices across the five studied megacities. Population density, business density and crime had only minor impacts on real estate prices. Our analysis of the landscape ecology variables in Lima and Buenos Aires also show that the relationship between green space and price is context-specific, which indicates that further research is needed to better understand when and where ecological attributes of green space affect real estate prices so that managers of urban green space in LA cities can optimize ecological configuration to maximize ecosystem service provision from often limited green spaces. © 2017 by the authors.