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Stimulated by the rising demand for bioenergy, forestry practices for energy production are of increasing importance worldwide. Black locust (Robinia
pseudoacacia L.) is a suitable tree species for biomass production in shortrotation plantations in East Germany, especially on marginal land where insufficient water and nutrients are a limiting factor for tree growth. Our study aims to clarify the spatial and temporal variability of the black locust growth through the analysis of the plant water status, and to evaluate the effect of adverse edaphic conditions on growth performances, amplified by periods of summer drought. The study was carried out at two sites presenting comparable climatic but different edaphic conditions: (i) fertile agricultural soil; and (ii) heterogeneous unstructured soil from a reclaimed post-mining area. During the vegetation period, the growth rate decreased in both sites following the plant water status in terms of pre-dawn leaf water potential. Particularly in the post-mining area, due to the adverse edaphic conditions, below the critical pre-dawn water potential value of -0.5 MPa, the stem growth was drastically reduced during a period of summer drought. However, the trees could cope with the extreme soil and weather conditions in the post-mining site without perishing.
Blattstreumengen in Gehölzstreifen und angrenzenden Ackerbreichen innerhalb eines Agroforstsystems
(2015)
Due to its ability to grow on marginal sites black locust (Robinia pseudoacacia L.) has been widely planted as a short rotation coppice (SRC) system that produce a renewable biomass feedstock in several post-mining areas of East Germany. However, as most of these sites are still in an initial stage of reclamation with low humus and nutrient contents, phosphorous can play a significant role as a plant limiting factor, because legumes require more P than other plants for their development. In April 2011, two experiments were conducted to evaluate the influence of higher rates and different applications of phosphorus fertiliser on the nutrition, survival, and biomass production of two different-aged black locust SRC plantations on the post lignite-mining site “Welzow-Süd”, situated in NE Germany. Treatments were applied as triple superphosphate (30, 60 and 120 kg P ha-1) and PK fertiliser (60 kg P ha-1) through broadcasting or banding on recently harvested or planted trees, respectively. Soil, leaf and woody biomass data were analysed utilising the Mann-Whitney U test and the Spearman correlation coefficient (rS). Following two growing seasons, it was observed that the total dry weight yields of the black locust seedlings were increased strongly by up to 8 times when compared to the control group, particularly when TSP was applied through banding. P fertilisation, however, did not affect the biomass yield of six-year-old black locust trees, but P concentration in leaves among treatments of both sites was still significantly increased and sufficient from a quantity upwards of 60 kg P ha-1. Taken together, a comparably moderate amount of P fertiliser (60 kg ha-1) had a strong impact on P uptake and growth performance in the examined black locust seedlings, which reveals a high potential to improve the current fertilisation practices for SRC black locust plantations grown on our research site.
Conventional agricultural practices have often been associated with negative externalities, such as land degradation, pollution of soil and water resources, loss of biodiversity, and decreased provision of ecosystem services (ES). In response to these negative effects, the number of indicator-based attempts to assess ES provided by land use systems has increased. However, decisions regarding the importance of the different ES are usually made subjectively. Following an objective approach through the use of a partial order ranking method, this study aimed to assess several non-provisioning ES supplied by alley cropping system (ACS) in comparison with conventional agriculture (CA). The main objective of the study was to verify the applicability of partial order ranking to an ecologically-based assessment, focusing on soil, water, and biodiversity indicators. Results from 40 hypothetical scenarios representing various site conditions of agricultural fields in Germany were calculated using the Ecosystem Services Assessment Tool for Agroforestry (ESAT-A), a toolbox designed to assess selected ES of ACS following an empirical approach. The results were ranked using partial order and were visualized by a Hasse diagram. The findings depict partial order ranking as a promising technique to support decision making in order to find priority scenarios and indicators where the provision of ES can be enhanced by establishing ACS. The minimal scenarios under CA identified with simultaneously low values of all indicators were perceived as target scenarios for establishing ACS. The values of the indicators for the current land use system need to be taken into account in order to avoid scenarios where high tradeoff was suggested. Additionally, this approach can be extended and utilized at the field level to aid farmer decisions on which land use strategy is the most suitable alternative to increase the provision of ES.
Understanding of soil carbon dynamics after establishment of alley-cropping systems is crucial for mitigation of greenhouse CO2 gas. This study investigates soil CO2 fluxes in an alley-cropping system composed of tree strips of black locust (Robinia pseudoacacia L.) and poplar (Populus nigra 9 P. maximowiczii, Max 1) trees and adjacent to them crop strips (Lupinus/Solarigol). Soil CO2 flux was measured monthly over a period from March to November 2012, using a LI-COR LI-8100A automated device. Concurrently with CO2 flux measurements, soil and air temperature, soil moisture, microbial C and hot water-extractable C were determined for the soils nearby soil collars. Root biomass was determined 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 photosynthesis, and therefore supply of carbohydrates from leaves to rhizosphere, over the warm summer months. A positive correlation between CO2 flux and soil moisture over the warm period indicates an enhancing role of soil moisture on microbial mineralization and root respiration. Average CO2 flux values observed over March–November period did not differ significantly between sampling areas, showing 2.5, 3.2, and 2.9 lmol m-2 s-1 values for black locust, poplar and crops, respectively. Significantly higher CO2 flux values over the summer period in trees could be attributed to the higher photosynthetic activity and higher root density compared to crops.
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.
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.
The cultivation of fast growing trees on agricultural sites is an area undergoing a growth in interest due to the rising demand for woody biomass as a source of bioenergy. Short rotation alley cropping systems (SRACS) represent a promising possibility to combine annual crops for food, fodder or bioenergy with woody plants for biomass production, doing so through an integration of hedgerows of fast growing trees into conventional agricultural sites. Against such developments, the question has arisen as to what extent hedgerows in SRACS can act as an effective windbreak despite their management-related low height of only a few meters. On the basis of multiannual recorded wind velocity data in high resolution at two sites in Germany, it could be shown that the wind speed on crop alleys was reduced significantly by such hedgerows. At the central point of 24 m wide crop alleys, the wind speed decreased on an annual average basis by more than 50 % when compared to the wind speeds of open field. The overall amount of reduction was strongly dependent on the location within the crop alleys, the height of trees, the distance between two hedgerows, and their orientation. In reflection upon these results, it was concluded that the establishment of SRACS could lead to enhanced soil protection against wind erosion and thus to ecological and economic benefits for agricultural sites.
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.
Short-rotation forestry and agroforestry systems have the potential to become an ecologically valuable and economically profitable land use alternative on marginal lands. Therefore, our project focuses on determining the water demand for biomass production of black locust in the Lusatia region (Eastern Germany). The area is characterized by relative low annual rainfall (560-600 mm/yr) and drought periods during spring and summer. Black locust (Robinia pseudoacacia L.) is planted in short rotation plantations as well as in agroforestry systems at reclaimed post-mining sites of the opencast mining area “Welzow Süd” and on a conventionally managed field near the town Forst (both study sites are located about 120 km to the south of Berlin). Due to mining activities the ground water table in “Welzow-Süd” is below 100 m, while on the field site in Forst the ground water table is about 2 m below the soil surface. Because of the water accessibility directly affecting the yield, it is crucial to identify the spatial variation of the soil water availability and its influence on black locust growth. The main question of this study is how the drought periods affect black locust’s growth and recovery and about the drought mitigation effect obtainable by an accessible water table. The growth rate is being estimated monthly by measuring the maximum height and the trunk diameter at 10 and 130 cm. Furthermore, several trees are equipped with dendrometers to record their diameter increment in daily intervals. The pre-dawn water potential for selected trees is evaluated periodically to quantify plant water stress and relate it to the growth pattern. Water availability and microclimatic condition are monitored continuously. At the end of the vegetation period, information gathered from the field will be used to develop a growth model to link the soil water availability and plant water status with the growth rate of the trees.
Since the 1920s, more than 80.000 ha of land have been affected by lignite opencast mining activities in the Lusatia region (Eastern Germany), resulting in the evolution of large post-mining landscapes with substrates poor in humus and nutrients. As a consequence, the current conventional crop production on these post-mining areas is restricted. Against this background, the increasing demand for woody biomass for bioenergy, and thus the cultivation of fast growing trees for woody biomass production, could represent a promising option to enhance the productivity of land reclaimed from mining. Accordingly, considerable research has been carried out over the last two decades on reclamation technology, in addition to attempts to improve the soil quality through the use of different fast growing tree species in the Lusatia lignite region. Through such studies, it has been shown that it is possible to cultivate a sustainable supply of bioenergy wood through the use of black locust (Robinia pseudoacacia L.) trees, even under the unfavourable growth conditions of the marginal post mining areas. Since this knowledge is mainly based on studies of monocultural plantations (SRC), in 2007 a short rotation alley cropping system (SRACS) was established in the reclaimed lignite mining site “Welzow-Süd” with the purpose of obtaining fresh insight. The present paper evaluates the positive impacts of agroforestry land-use in terms of soil fertility, agricultural crop production, and soil protection against wind erosion based on the results of several years of examination made in this degraded area.
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.
Ökologische und ökonomische Bewertung von Agroforstsystemen in der landwirtschaftlichen Praxis
(2008)
Alley-Cropping - Ein klima-adaptierbares Landnutzungssystem zur nachhaltigen Biomasseproduktion
(2008)
Polistichus connexus (GEOFRROY in FOURCROY, 1785) - neu für Brandenburg (Coleoptera, Carabidae)
(2010)
An approach to extrapolate categorical agricultural soil data to nonmapped areas using majority vote
(2009)
Energieholzproduktion in Agroforstsystemen als ein Beitrag zur Verbesserung des Bodenschutzes
(2010)
Der Agrarholzanbau stellt allgemein eine sehr extensive Form der landwirtschaftlichen Flächennutzung dar. So können beispielsweise die Winderosion
oder der Stoffaustrag in das Grundwasser durch den Anbau von Bäumen auf ackerbaulich genutzten Standorten deutlich reduziert werden. Durch die Kombination von Bäumen und konventionellen Ackerfrüchten (Agroforstwirtschaft) können auch angrenzende Feldfruchtbereiche und somit der gesamte Ackerschlag von diesen positiven Effekten des Agrarholzanbaus profitieren. Im Rahmen dieser Studie wurde beispielhaft untersucht, ob und inwieweit der streifenförmige Anbau (Alley-Cropping) von im Kurzumtrieb bewirtschaftetem Agrarholz einerseits zu einer Verbesserung des Windschutzes und andererseits zu einer Erhöhung der Grundwasserqualität beitragen kann.
Agroforestry systems for the production of woody biomass in marginal regions in Northeast Germany
(2011)
Blattstreu-Umsatz in Robinien-Kurzumtriebsplantagen auf Lausitzer Tagebau-Rekultivierungsflächen
(2011)
Fast growing tree species in alley cropping systems and their influence on microclimate in Germany
(2013)
Als Pionierbaumart besiedelt die Robinie (Robinia pseudoacacia) schnell offene Flächen und gilt im Vergleich zu anderen mitteleuropäischen Baumarten als relativ gut angepasst an trockene Standorte mit lockeren Böden. Sie gehört zu den wenigen Baumarten Mitteleuropas, die zur biologischen Stickstoff-Fixierung (BNF) befähigt sind. In dieser Studie soll der jährliche Eintrag von Stickstoff (N) aus der biologischen N-Fixierung der Robinie in Kurzumtriebsplantagen und Agroforstsystemen abgeschätzt werden.