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This study assessed the provision of additional ecosystem services by two alley cropping systems for production of woody biomass located in Germany (Farm A and Farm B) as compared to conventional agricultural management. Stripes of fast growing trees in both farms were planted at different distances from each other and occupied various proportion of the agroforestry area. The results of nine indicators of soil, water and biodiversity related to ecosystem services were thus compared under consideration of different farm conditions and management. The additional provision of benefits in Farm A was expected in terms of reducing erosion by wind and reducing the risk of nitrate leaching to groundwater. In Farm B the main effect was related with improving biodiversity. The design of the tree stripes within the system affected the reduction of wind erosion as well as the improvement in biodiversity and was an essential factor determining the provision of ecosystem services by alley cropping systems.
Linear woody-features, such as hedgerows, windbreaks, and riparian buffer strips, composed of trees and/or shrubs are anthropogenic features, established in the past for different purposes, such as provision of field boundaries, protection from wind and supply of fuelwood. Today, they are primarily valued for their ecological benefit, while their production function has received rather little attention. This study assessed the biomass potential of existing linear woodyfeatures in a study area in southern Brandenburg, Germany. The merchantable tree volume of the measured woody-features ranged between 240 m3 ha-1 and 710 m3 ha-1, depending on the relative proportion of trees and shrubs. The results suggest that the biomass potential of linear woody-features with predominant tree proportion per hectare can be higher than this of forests.
A strategy for utilising the production function of these woody-features should take into account the provision of benefits such as wind protection, habitat provision and landscape aesthetics.
Damit Landwirte Agroforstsysteme verstärkt umsetzen, müssen Agroforstflächen mindestens genauso förderberechtigt sein wie konventionelle Ackerfruchtflächen. Bislang finden Agroforstsysteme im deutschen Agrarförderrecht jedoch keine Berücksichtigung. Da die Agroforstwirtschaft eine sehr komplexe Form der Landnutzung ist, muss eindeutig dargelegt werden, unter welchen Bedingungen es sich um Agroforstflächen handelt und wann nicht. Hierfür ist eine Definition von Agroforstschlägen erforderlich, die den Agrarbehörden eine Kontrollfähigkeit ermöglicht. Eine solche Definition, die Gehölzkulturen und Ackerkulturen auf einem Schlag vereint, ist bislang nicht mit dem deutschen Agrarförderrecht vereinbar. Dennoch erscheint es sinnvoll und notwendig, dass sich in den Agrarbehörden, vor dem Hintergrund einer verstärkt geforderten Multifunktionalität in der Landwirtschaft, mehr und mehr von sektoralen Denkmustern verabschiedet und neuen integrativen Landbausystemen zugewandt wird. Hierzu könnte die agrarförderrechtliche Implementierung von Agroforstsystemen einen wertvollen Beitrag liefern. Der folgende Aufsatz zeigt mit dem Vorschlag für eine Agroforstschlag-Definition einen konkreten Lösungsansatz für den behördlichen Umgang mit dieser Bewirtschaftungsform auf.
Im Rekultivierungsbereich des Braunkohletagebaus Welzow-Süd wurde der Einfluss der Schnitttechnik auf die Biomassequantität, die Stockausschlagfähigkeit und die Entwicklung von Robinien Wurzelbrut untersucht.
Für diesen Zweck wurden die Folgen der Holzernte mittels Forstmulcher und Motorsäge miteinander verglichen.
Understanding of soil carbon dynamics after establishment of alley-cropping systems is crucial for mitigation of greenhouse gas CO2. This study investigates soil CO2 flux in an alley-cropping system composed of black locust (Robinia pseudoacacia L.) and poplar (Max 1) tree strips and adjacent to them crop strips (Lupinus/ Solarigol). Soil CO2 flux was measured monthly over the March – November 2012 period, using a LI-COR LI-8100A automated device. Simultaneously with CO2 flux measurements, soil and air temperature, soil moisture, microbial C and hot water-extractable carbon (HWC) were determined for soils collected nearby each measurement collar. Root biomass was measured to a depth of 15 cm. In all sampling areas, soil CO2 flux increased from May to July, showing a significant positive correlation with air and soil temperature, which can be a reflection of increase in photosynthetic activity over the warm summer months. The relationships between soil moisture and CO2 flux showed positive correlation only for the warm period (May - October), indicating enhancing role of soil moisture on microbial mineralization and root respiration. CO2 flux values varied between sampling areas at different vegetation periods, with significantly higher values in trees over the summer. This could be attributed to the higher photosynthetic activity and higher root density in trees coppices compared to crops. In autumn, after seeding catch crop mix Solarigol, CO2 flux was significantly higher in crops compared to trees, which could be related to soil tillage prior to seeding of crops, as well as to the higher photosynthetic activity of newly seeded crops at the period of rapid plant growth. Despite a seasonal variation in CO2 flux between sampling areas, aaverage CO2 flux values observed over March – November period did not differ significantly between sampling areas, showing 2.5, 3.2, and 2.9 μmol m-2 s-1 values for black locust, poplar and crops, respectively. A greater C loss with soil respiration under trees in summer period may be compensated by greater C assimilation and storage in woody biomass, and the greater respiration from crop strips after tillage in autumn.
The production of energy wood on arable land increased in Germany during the last years. Black locust (Robinia pseudoacacia L.) is a suitable tree species in order to ensure substantial woody biomass yields on agricultural sites in eastern Germany. Arranged in hedge structures (alley cropping) positive effects on wind velocity and hence on soil erosion can be expected for the whole agricultural production area.
Results of field measurements carried out in several alley cropping sites located in eastern Germany show that wind velocity can be reduced by more than 50 %, even though tree hedgerows were not higher than four meters. Here, the reduction of wind speed was dependent on the distance to woody crops, the width of the crop alleys and the orientation of hedgerows. As a result of wind speeds reduction the potential of soil erosion by wind decreases considerably. The risk of wind erosion is even nearly negligible for 24 m wide or smaller crop alleys.
The establishment of short rotation hedgerows could contribute to an enhanced protection against wind erosion and thus to an ecological and possible long-term economic appreciation of agricultural sites. Aside from erosion control, further advantages such as a lower evaporation rate, and thus a crop yield increase, may be connected to the establishment of such agroforestry systems. Against the background of the increasing demand for woody biomass for bioenergy, the cultivation of fast growing trees on agricultural sites can furthermore result in an additional incomefor farmers. This is a prerequisite for the spread of this kind of agroforestry in Germany, because a comparable large share of an unprotected field has to be planted with trees in order to ensure an efficient windbreak.
Die Agroforstwirtschaft, also die kombinierte Nutzung von Bäumen und Feldfrüchten auf einer landwirtschaftlichen Fläche, gewinnt vor dem Hintergrund der steigenden Holznachfrage sowie diverser ökologischer Vorteilswirkungen auch in Deutschland
zunehmend an Bedeutung. Verglichen mit den bereits bekannten Umweltleistungen, wie etwa einer erhöhten Biodiversität sowie dem Schutz vor Winderosion, ist der potenzielle Einfluss der Gehölzstreifen auf das Wachstum bzw. die Nährstoffversorgung von angrenzenden Feldfrüchten in Agroforstsystemen noch weitestgehend ungeklärt. Zur Quantifizierung dieser möglichen Interaktion wurden im Jahr 2013 auf einem etwa 40 ha großen Agroforst-Versuchsstandort nahe der Stadt Forst (Lausitz) umfangreiche Nährstoff- und Ertragsuntersuchungen durchgeführt.
ln der Region Südbrandenburg herrschen ertragsschwache, sandige Böden vor, die von Natur aus ein geringes Wasserhaltevermögen und ein hohes Degradationspotential durch Winderosion aufweisen. Zudem existiert hier ein
vergleichsweise großer Flächenanteil an strukturarmen, großflächigen Bergbaufolgelandschaften, die sich zume1st durch eine geringe Standortsgüte auszeichnen. In diesem Beitrag werden Ergebnisse aus versChiedenen Studien vorgestellt, in denen untersucht wurde, ob und in welchem Ausmaß durch im Kurzumtrieb bewirtschaftete Agroforstsysteme die Anfälligkeit dieser Ackerstandorte gegenüber Winderosion gemindert und die im Boden bzw. Kippensubstrat vorhandene Menge an organischer Substanz erhöht werden kann.
Alley cropping system is an agroforestry practice in which arable crops are cultivated between tree hedgerows. For more than 15 ye ars we have been doing research in agroforestry which has been carried out on different experimental sites in the field covering about 250 acres of alley cropping, more areas with short rotation coppice, and other tree-based field experiments located close to C ottbus / Germany. The presence of woody species in the alley cropping production system has been shown to contribute significantly to carbon sequestration, nutrient cycling, improved water availability for crops, stimulation of higher soil faunal activities, soil erosion control, soil fertility improvement and sustained levels of crop production.
Alley cropping systems have also come into focus for reclamation of post-mining areas where the initial content of soil organic matter (SOM) is generally close to zero and soil fertility is very low. The increase of SOM in reclamation areas depends on amount of biomass production and return to soil, and mechanisms of C protection. Production of Robinia pseudoacacia L. under alley cropping system has received considerable interest in these areas as an alternative to agricultural crops and an additional wood source, while acting as a potential C sink to counterbalance greenhouse gases emissions. The woody biomass accumulation of R. pseudoacacia reached 29.8 t drymass ha-1 after 6 years of establishment on reclaimed mine sites in northeastern Germany. Due to its high potential of litterfall production and N2 fixation, R. pseudoacacia contributed to improve soil physical, chemical and biological properties though increasing SOM, converting spoils into productive and sustainable soils. For this reason, in the temperate zone, agroforestry systems attract more and more public attention as they offer a promising and comprising way for adapting agricultural production to climate change and providing comprehensive ecosystem services. A comprehensive assessment of the ecosystem services in agroforestry systems in temperate regions should consider the potential to produce biomass and food, the evaluation of the carbon and nutrient budgets, the assessment of the potential impact of agroforestry on biodiversity at landscape scale and finally the exploration of the sustainability functions and socio-economic cross-cutting issues. These key parameters are relevant to policy by providing current and reliable information on the interactions between land management, ecosystem services and society.
Alley-Cropping - Ein klima-adaptierbares Landnutzungssystem zur nachhaltigen Biomasseproduktion
(2008)
Ökologische und ökonomische Bewertung von Agroforstsystemen in der landwirtschaftlichen Praxis
(2008)
Intestinal colonization is influenced by the ability of the bacterium to inhabit a niche, which is based on the expression of colonization factors. Escherichia coli carries a broad range of virulence-associated genes (VAGs) which contribute to intestinal (inVAGs) and extraintestinal (exVAGs) infection. Moreover, initial evidence indicates that inVAGs and exVAGs support intestinal colonization. We developed new screening tools to genotypically and phenotypically characterize E. coli isolates originating in humans, domestic pigs, and 17 wild mammal and avian species. We analyzed 317 isolates for the occurrence of 44 VAGs using a novel multiplex PCR microbead assay (MPMA) and for adhesion to four epithelial cell lines using a new adhesion assay. We correlated data for the definition of new adhesion genes. inVAGs were identified only sporadically, particularly in roe deer (Capreolus capreolus) and the European hedgehog ( Erinaceus europaeus). The prevalence of exVAGs depended on isolation from a specific host. Human uropathogenic E. coli isolates carried exVAGs with the highest prevalence, followed by badger (Meles meles) and roe deer isolates. Adhesion was found to be very diverse. Adhesion was specific to cells, host, and tissue, though it was also unspecific. Occurrence of the following VAGs was associated with a higher rate of adhesion to one or more cell lines: afa-dra, daaD, tsh, vat, ibeA, fyuA, mat, sfa-foc, malX, pic, irp2, and papC. In summary, we established new screening methods which enabled us to characterize large numbers of E. coli isolates. We defined reservoirs for potential pathogenic E. coli. We also identified a very broad range of colonization strategies and defined potential new adhesion genes.
Development of a Method for Multiplex Real-Time Analysis of Enzymatic Activity on a Microbead-Chip
(2013)
Abstract
BACKGROUND:
Different strategies of colonization or infection by E. coli result in formation of certain adhesion patterns which help also in classifying intestinal E. coli into pathotypes. Little is known about adhesion patterns and host- and tissue adaption of commensal E. coli and about E. coli originating in clinically healthy hosts carrying pathotype-specific virulence-associated genes.
FINDINGS:
Adhesion pattern of E. coli (n = 282) from humans and from 18 animal species were verified on intestinal human Caco-2 and porcine IPEC-J2 cells and, furthermore, for comparison on human urinary bladder 5637, porcine kidney PK-15 epithelial and HEp-2 cells. The analysis was carried out on 150,000 images of adhesion assays.Adhesion patterns were very diverse; 88 isolates were completely non-adherent, whereas 194 adhered to at least one cell line with the dominant adhesion patterns "diffusely distributed" and "microcolony formation". Adhesion patterns "chains" and "clumps" were also visible. Chain formation was mediated by the presence of epithelial cells. Clump formation was very specific on only the 5637 cell line. All enteropathogenic (eae+) E. coli (EPEC; n = 14) were able to form microcolonies which was cell line specific for each isolate. Most EPEC formed microcolonies on intestinal IPEC-J2 and Caco-2 but several also on urinary tract cells. Shigatoxin-producing (stx+) E. coli (n = 10) showed no specific adhesion patterns.
CONCLUSIONS:
E. coli isolates were highly diverse. Commensal and pathogenic isolates can adhere in various forms, including diffuse distribution, microcolonies, chains and clumps. Microcolony formation seems to be a global adhesion strategy also for commensal E. coli.
Short rotation coppice (SRC) is seen as a successful management system, which in addition to energy wood production may enhance soil carbon sequestration. The objective of this study was to investigate total, labile and stable soil carbon fractions at SRCs composed of poplar clones Max 1 (Populus nigra x P. maximowiczii), Muhle Larsen (Populus Trichocarpa), and black locust (Robinia pseudoacacia L.). Study was conducted at three SRC sites (Allendorf, Dornburg, and Forst) varying in age (1–4 years old), soil texture and climatic characteristics, in Germany. Composite soil samples collected at SRCs from 0 to 3; 0–10; 10–30; and 30–60 cm depth layers were compared with soils collected from adjacent crop strips. Samples were analysed for total organic carbon (TOC), hot-water extractable carbon (HWC), and organic carbon (OC) at 250–2,000; 53–250; and\53 lm soil-size aggregates. Total OC stocks in 0–60 cm soil layer were the highest at the site with the heaviest texture, Dornburg, followed by Forst and Allendorf, comprising 92–107; 59–74; and 53–64 Mg ha-1, respectively. Although no significant differences in the total OC stocks between SRCs and adjacent crops were found for the 0–60 cm layer, a significantly (p\0.05) higher TOC, HWC, OC at macroaggregates (250–2,000 lm), and the amount of macro-aggregates were found in the top 0–3 cm layer in all SRC sites (except the youngest poplar SRC in Forst) compared to adjacent crop strips. A greater macro-aggregate formation in SRCs related to the lower soil disturbance compared to the tilled crops, revealed a potential of SRC for C sequestration, as C occluded within soil aggregates has a slower decomposition rates and longer residence time.
Agroforestry is receiving increasing attention in Germany because of its capacity to address some of the negative consequences of intensive agriculture. However the actual uptake and maintenance of agroforestry by farmers remains low. The aim of this study was to identify the opportunities and obstacles to agroforestry in Germany and to identify potential measures which could address the obstacles and increase agroforestry adoption. Qualitative interviews with 32 farmers indicated that the legal framework and administrative burden associated with agroforestry in Germany was a major obstacle. The farmers recognised that agroforestry provided environmental benefits, but these do not always increase farm profitability. Agroforestry was identified as a viable alternative to conventional farming systems, especially in less productive areas, not profitable when managed in a conventional way. To enhance the implementation of agroforestry the simplification of the legal framework is crucial. Modern agroforestry should be better recognized by existing policy measures providing payments for environmentally friendly farming. Ultimately, an integrated approach for environmental benefits and production objectives is required, which is based on rewarding farmers for providing ecosystem services (ESs) and a stronger public involvement in sustainable land use practices. Rewarding farmers for ESs could increase the interest in agroforestry in highly productive areas, enhancing sustainable land use in the long term.
The aim of this study was to evaluate the potential of short rotation alley cropping systems (SRACS) to improve the soil fertility of marginal post-mining sites in Brandenburg, Germany. Therefore, we annually investigated the crop alleys (AC) and black locust hedgerows (ABL) of a SRACS field trail under initial soil conditions to identify the short-term effects of tree planting on the storage of soil organic carbon (SOC) and its degree of stabilization by density fractionation. We detected a significant increase in SOC and hot-water-extractable organic C (HWEOC) at ABL, which was mainly restricted to the uppermost soil layer (0–10 cm). After 6 years, the SOC and HWEOC accumulation rates at ABL were 0.6 Mg and 46 kg ha−1 year−1, which were higher than those in the AC. In addition, comparatively high stocks of approximately 4.6 Mg OC and 182 kg HWEOC ha−1 were stored in the ABL litter layer. Density fractionation of the 0–3 cm soil layer at ABL revealed that the majority of the total SOC (47%) was stored in the free particulate organic matter fraction, which was more than twice that of the AC. At the same time, a higher and steadily increasing amount of SOC was stored in the occluded particulate organic matter fraction at ABL, which indicated a high efficiency for SOC stabilization. Overall, our findings support the suitability of black locust trees for increasing the soil fertility of the reclaimed mining substrate and, consequently, the high potential for SRACS to serve as an effective recultivation measure at marginal sites.