TY - THES A1 - Meyer zu Drewer, Johannes T1 - Soil- and Tree- Biomass Carbon as Future Farming Commodity for Smallholders in Tropics and Sub- Tropics - A Concept Review N2 - Facing prevalent soil degradation, population growth and climate change it is vital to wildly deploy versatile carbon farming practices [CF] to increase soil organic carbon [SOC] stocks and consecutive restore soils, increase their productivity and climate resilience while directly mitigating climate change through sequestration of greenhouse gas- [GHG] derivatives, such as CO₂-Carbon, in agricultural landscapes. The global aggregated mitigation potential of up to 11 GtCO₂eq yrˉ¹ (medium confidence) resulting from afforestation, SOC increment and biochar application in the land use sector can only be realised when including smallholder farmers which are in stewardship of 60% of the global arable lands. Currently soil carbon sequestration receives extensive attention, but efficient schemes to financially support smallholder transition towards carbon farming practices are lacking. Linking these smallholder structures to the global carbon markets by verifying and trading carbon offsets generated through climate smart farming practices is a new attempt to generate the required funding for transition – turning carbon into a new farming commodity for smallholders. This paper reviews approaches to SOC monitoring required for quantification and verification of offsets, based on the evaluation of methods used in the Nepalese smallholder carbon project: Forest Gardens for Closing the Global Carbon Cycle [FCGC]. Further it compares the project innovations of the FCGC with other distinguished case studies of current projects implementing carbon as a farming commodity in a tropical- subtropical smallholder context. A strong variability in SOC pattern as identified in the FCGC project, is inherent to smallholder systems, the cost of representative, direct measurements of such heterogeneous SOC distributions may be cost prohibitive. For smallholder carbon projects of aggregated scale, process-based models to determine SOC fluxes should be employed or the agricultural intervention be focused on tree- biomass- carbon which is quantifiable in a less resource demanding manners. Among the identified project innovations are: Real- time in-situ GIS applications, an innovative approach for monitoring fragmented areas under intervention; The household segment of the voluntary carbon market as a new target group to be explored; Biochar as a multifunctional soil amendment for long-term carbon sequestration; Participatory schemes for monitoring and extension services to build capacity and foster participation; and mobile money approaches to lower transaction costs and likelihood of corruption. The direct financial return from carbon- credits to the farmer is minor, thus it is imperative for the project design to utilize agricultural interventions fostering co-benefits, which are tangible to the farmer in the short to medium term and will serve as the main incentive for the adoption of CF techniques. KW - Carbon farming KW - Carbon sequestration KW - Smallholder agriculture KW - Carbon finance KW - Climate change mitigation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-3646 ER - TY - THES A1 - Tanzin, Tamanna T1 - Assessment of growth and yield potential of different vegetable amaranth type in Kleve, Germany N2 - Amaranthus belongs to the Amaranthaceae family which has approximately 70 species. It is considered as an underutilized plant but some research in the recent years showed that it is a promising plant for future nutrition supply. Amaranths are widely known for its nutritional value and their easy growing habit. This underutilized plant can become a good option for the commercial growers because it is easy to grow, it has high nutritional value and low maintenance cost. Many species of the Amaranthus genus are known as annual weeds, some are used as a vegetable and ornamental plants, some are known as pseudocereals which are mainly used for their grain. The core objective of this study was to assess the growth and yield potential of different vegetable amaranths to select a suitable variety for Kleve, Germany. Eight vegetable amaranths variety (Leafy variety and Stem variety) were grown in the experimental garden of Hochschule Rhein-Waal University. A seed germination test was also conducted at thelife science lab to observe the best seed germination rate at different temperatures. Plant height, number of leaves per plant were measured continuously after two weeks of sowing till the harvest week. The fresh and dry weight of leaf, stem and root were measured after final harvest. The statistical analysis of growth and yield performance of stem and leafy varieties were done separately. Leafy varieties showed a high variation in yield and germination rate than stem varieties. Leafy variety 'Surinamese Spinach'(L7) and 'Marog Green' (L8) excelled in all yield parameters whereas 'Chinese Spinach' (L6) was consistent in low growth and yield. Stem variety 'Danta Bhutan' (S2) and 'Danta Lusina' (S3) showed low yield performance. All the varieties showed a high germination rate above 20°C in seed germination test. Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-2711 ER - TY - THES A1 - Höft, Mattis T1 - Influence of humic acids on nutrient use efficiency of three phosphorus sources in a sandy soil N2 - A pot trial was conducted under greenhouse conditions to assess the effect of humic acid (HA) application in combination with rock phosphate (RP) on the plant phosphorus (P) nutrient use efficiency (NUE), in comparison to the performance of struvite (ST) and triple superphosphate (TSP) amended plants. A sandy soil, exhibiting a low P content, was used in combination with a lignite derived, liquid humic acid product, with a HA content of 4.8 %. Nine groups of perennial ryegrass (Lolium perenne L.) were set up as experimental plants, in replications of six, each containing 4.5 kg air dry soil with a P supply of 27 mg P kg-1 soil, causing P deficiency during the experiment. HA was applied at rates of 1, 30 and 100 mg kg-1 soil, directly to the soil as coated RP or as foliar application. Aboveground biomass was harvested biweekly, five times in total. Amendment performance was evaluated by analysing plant biomass, soil pH, plant phosphorus-, carbon-, nitrogen-, iron-, zinc-, manganese- and boron contents. The label doses of 1 mg kg-1 soil as well as 100-fold increases in HA concentration didn’t result in a significant difference in plant shoot or root growth and P NUE compared to untreated plants. Positive trends were displayed at higher foliar application rates. Plant tissue micronutrient concentrations of HA treated samples were generally lower and partly significantly lower than the control. The detected effects were accredited to the hormone-like influence of HA on plants’ metabolism and the ability to alter soil conditions. The lack of calcium in ST amended samples resulted in better plant P availability, significantly higher P uptake and better shoot biomass development. Trends show that ST could be applied in combination with HA to further increase plants P NUE in the future. KW - Humic acid KW - Phosphorus KW - Struvite KW - Rock phosphate KW - Triple superphosphate Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-2978 ER - TY - THES A1 - Paschen, Blanca T1 - Differences in root morphology of modern wheat and barley varieties and their wild ancestors N2 - Sustainable agriculture requires plants which are able to absorb water and nutrients more efficiently to avoid losses and to reduce negative effects on the environment. Root traits are vitally important to fulfill these aims. Therefore, it is important to better understand root morphology of common cereals, such as wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) and their wild relatives. Wild wheat and barley relatives have a superior root system and thus may provide a valuable biological resource for breeding stress tolerant cereals in the future. The objectives of this research were to characterize the variability of root traits among modern wheat and barley cultivars and their wild forms. Fifteen wheat and nine barley cultivars and wild forms were grown under optimal growth conditions without addition of nutrients in a greenhouse experiment. Cultivars and wild forms showed a high genetic variation in root morphology, as well as in shoot traits. Cultivars were divided into three domestication categories: wild forms, old cultivars and modern cultivars. A high variability while comparing cultivars at domestication level showed that it is a 4 weak predictor for root traits. A deep and large root system, high root length density and a high root to shoot ratio were identified as being beneficial traits for efficient nutrient and water uptake. T. aestivum var. tschermakianum, Aegilops cylindrica, H. vulgare hexastichon and H. lagunculiforme had highest values for these traits. Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-1948 ER - TY - THES A1 - Nitsch, Ellen Sophie T1 - Opportunities and challenges of Black Locust (Robinia pseudoacacia L.) as a neophyte in temperate climate zones and potential approaches to management in the case of the urban area of Cleve, Germany. N2 - Black locust (Robinia pseudoacacia L.), a deciduous, nitrogen fixing tree of the family of the Fabaceae, can create opportunities as well as challenges in the areas it is found in. The gathering of information was done in three ways: 1) online research to gather basic information about the species, 2) communication with the Umweltbetriebe Kleve and the Niederrhein forestry office to obtain information about the situation in Cleve, Germany 3) visits to the different black locust stands to get an understanding of the situation. Black locust is a pioneer species with a short life span and is considered as an invasive neophyte in many European countries due to its strong suckering and ability to advance into habitats which then undergo an irreversible change in soil and species composition leading to biodiversity loss in especially threatened habitats such as dry grasslands. This is opposed by black locusts’ strong biomass production, making it well suited for plantation production, resulting in a strong, durable and fast growing multiuse wood as well as nutritious foliage which can be used as animal fodder or for the production of bioenergy. The 9 visited black locust stands situated in and around Cleve, Germany are well established middle-aged stands not used for the production of high value wood. These stands were considered as not threatening to their adjacent environments due to their being surrounded by streets, waterbodies and well maintained fields and parks making a spread unlikely. As the stands are quite old already letting them fade out by natural succession would be the recommended management method. Should the need for removal present itself, girdling would be the suggested technique as, even though it is quite time intensive, it is the least forceful method and thus minimises the possibility of a strong suckering reaction. In conclusion it can be said, that its usage and management system strongly depend on the location and closeness to threatened habitats, considering that, the environmental aspect should always be put before the economic benefits. KW - Robinia pseudoacacia KW - Black locust KW - Invasive neophyte KW - Cleve KW - Opportunities and challenges Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-8720 ER - TY - THES A1 - Rohlfing, Pauline T1 - Einfluss von Benzalkoniumchlorid auf die Selektion von Bakteriengemeinschaften und die Verbreitung von Resistenzgenen in mit Mikroplastik angereichertem Boden N2 - Die zunehmende Anreicherung anthropogener Mikroverunreinigungen in der Umwelt hat in jüngster Zeit verstärkte wissenschaftliche Aufmerksamkeit erhalten. Der steigende Eintrag von Mikroplastik in die Umwelt kombiniert mit der Ausbreitung von Resistenzgenen erfordert eine eingehende Analyse ihrer möglichen Interaktionen und Auswirkungen auf die Ökosysteme. In dieser Studie stand die Interaktion zwischen Mikroplastik, speziell HDPE, einem nicht biologisch abbaubaren Polymer, und PHBH, eine biologisch abbaubare Alternative, in Kombination mit Benzalkoniumchlorid im Fokus. Ziel war es, deren Einfluss auf die Gemeinschaftsstruktur von Bodenmikroorganismen und die Prävalenz von Antibiotikaresistenzgenen zu untersuchen. Unter Verwendung eines Mikrokosmos- Designs wurden organisch bewirtschaftete Bodenproben mit den vorgenannten Substanzen über drei und sechs Wochen inkubiert. Im Anschluss wurden die Biofilme auf den Mikropartikeln mittels qPCR und ddPCR analysiert, wobei die Abundanz von Bakterien, Pilzen und dem Klasse-1-Integron-Gen untersucht wurde. Die Ergebnisse können nicht bestätigen, dass Benzalkoniumchlorid die Verbreitung von Resistenzgenen oder mikrobielle Gemeinschaftsstrukturen beeinflusst. Im Gegensatz dazu wirkte PHBH als signifikanter Modulator, der die Vielfalt der Pilz- und Bakterientaxa im Biofilm verringerte, jedoch die Gesamtabundanz erhöhte. Vor dem Hintergrund dieser Befunde werden die potenziellen ökologischen Implikationen der Mikroplastikverschmutzung deutlich. Es betont die Notwendigkeit vertiefter Forschungen, um die komplexen Wechselwirkungen zwischen Mikroplastik und anderen anthropogenen Kontaminanten in terrestrischen Ökosystemen zu verstehen. N2 - The increasing accumulation of anthropogenic micropollutants in the environment has received greater scientific attention in recent years. The rise of microplastics in the environment combined with the spread of resistance genes requires an in-depth analysis of their potential interactions and impacts on ecosystems. This study focused on the interaction between microplastics, specifically HDPE, a non- biodegradable polymer, and PHBH, a biodegradable alternative, in combination with benzalkonium chloride. The aim was to investigate their influence on the community structure of soil microorganisms and the prevalence of antibiotic resistance genes. Using a microcosm design, organically managed soil samples were incubated with the aforementioned substances for three and six weeks. Subsequently, biofilms on the microparticles were analysed using qPCR and ddPCR method, with particular emphasis on the abundance of bacteria, fungi and the class 1 integron gene. The results cannot confirm that benzalkonium chloride influences the dissemination of resistance genes or microbial community structures. In contrast, PHBH acted as a significant modulator, reducing the diversity of fungal and bacterial taxa in the biofilm, but increasing overall abundance. Given these results, the potential ecological implications of microplastic pollution become apparent. It emphasises the need for deeper research to understand the complex interactions between microplastics and other anthropogenic contaminants in terrestrial ecosystems. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-18573 ER - TY - THES A1 - Chng, Ci Ern Katelyn T1 - Effects of Sewage Sludge Biochar as a Growing Media Component and Phosphate Fertiliser on the Cultivation of Potted Ornamental Plants N2 - There is increasing pressure from the German government on its citizens to reduce dependency on phosphate rock and peat, in agriculture and horticulture. This is due to the phosphate rock oligopoly with associated political instabilities, and the environmental consequences of peat harvesting. Past studies on soilless crop cultivation have shown promising outcomes for the phosphorus (P)-rich sewage sludge biochar (SSB) as an answer to these issues. However, SSB remains as one of the least studied biochar types in soilless ornamental cultivation. The objectives of this study were to investigate the viability of SSB as a P fertiliser and growing media component in pot cultivation of lavender (Lavandula angustifolia), purple coneflower (Echinacea purpurea) and poinsettia (Euphorbia pulcherrima). The addition of SSB at a 10% (v/v) rate to coco peat (SSB 10) was determined as the best composition. Although it did not outperform the control, SSB 10 plants were not significantly lower than the control plants in height, dry aboveground biomass, and number of poinsettia stems across all three species – except in poinsettia biomass. Other rates (5%, 15%, 20%) had significantly lower values in more than one parameter. Physicochemical characterisation also revealed increased P with increasing SSB rates in the growing media. Contrary to other studies, the pH of all growing media did not exceed ideal growing media pH values (5.3-6.5), further solidifying SSB’s viability as a growing media component. The reliability of our results could be improved by recording water uptake of the media, and selection of species with quantifiable aesthetics. KW - Biochar KW - P recovery KW - Sewage sludge KW - Pyrolysis KW - Ornamentals KW - Substrate KW - Growing media KW - Peat reduction Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-22189 ER - TY - THES A1 - Vögerl, Jakob T1 - Assessing the effect of N-fertilisation on biomass development and plant interactions in the ancient Milpa compared to pure stands and its potential to reduce fertiliser inputs in traditional small-scale farming N2 - Over the past years, nitrogen (N) fertilisation has been identified as an issue that has a major negative impact on the environment. Therefore, sustainable agricultural practices aim to reduce external fertiliser inputs and focus more on naturally available resources and sustainable cropping practices. One example of that is the ancient milpa polyculture which is practised by traditional small-scale farmers in Central America. It consists of climbing bean (Phaseolus vulgaris var. vulgaris), maize (Zea mays), and squash (Cucurbita moschata) that are said to represent a holistic symbiosis in which beans assume the task to accumulate additional nitrogen via N2-fixation and subsequently transfer it to its companions. The potential of intercropping, and thus nitrogen transfer to level out and reduce nitrogen fertiliser inputs compared to monocultures has not been assessed yet and little is known about the resulting practical implementation for small-scale farmers. Therefore, a pot trial with monoculture treatments (100 kg N/ha) of each crop and milpa treatments with varying levels of nitrogen fertilisation (0, 25, 50, 75, and 100 kg N/ha) was established. The intercropped beans were labelled with the 15N isotope using the cotton wick method to track nitrogen transfer in the system. Further, the Land Equivalent Ratio (LER) was used to determine the productivity of the system. Results showed that all polyculture treatments performed similarly or significantly better than the pure stands in terms of total dry matter content per pot. Milpas provided with 100 and 25% of the recommended nitrogen rate were most productive and achieved a total LER of 1.25 and 1.30, respectively. Also, the non-fertilised milpa was still as productive as the respective plants grown in a monoculture. Due to external reasons, the importance of nitrogen transfer and the related microorganisms could not be evaluated. However, growing a milpa instead of monocultures enables farmers to greatly reduce N fertiliser inputs and provides higher yields in the growing season, while other intercropping benefits are also present. It further has the potential to maintain yields and enhance natural nutrient cycling even if no fertiliser is applied. KW - Milpa KW - Three sisters KW - Nitrogen transfer KW - Intercropping Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-6214 ER - TY - THES A1 - Brandt, Moritz Lasse T1 - The fungal endophyte Metarhizium brunneum: Possible multifunctional plant promoter in sustainable agriculture N2 - The overuse of mineral fertilizers and chemical pesticides in the world's agricultural sectors continues to be exorbitant, and is associated with a number of serious consequences for the entire complex environment. The reasons for this include the steadily growing world population and the accompanying degradation of the soil. As an alternative to chemical agents, biological plant protection/strengthening stimulants based on effective microorganisms have become established in the last decades. Research in recent years has focused on entomopathogenic fungal endophytes. The fungal endophyte Metarhizium brunneum, has long been proving its value as a mycoinsecticide in crop protection and there are indications of various plant-strengthening properties. The aim of this thesis is therefore to provide an overview of the current state of knowledge about the endophyte M. brunneum and at the same time, based on the literature, to discuss its potential as an alternative multifunctional plant promoter for sustainable agriculture. A literature research method was used to conduct a quantitative analysis of the existing knowledge on M. brunneum. The information and data collected as a result were systematically categorized and presented. The analysis has shown that the generalist M. brunneum covers a wide host range, has the ability to transfer nutrients in exchange, activates or produces plant hormones, compensates for stressors, and has many possibilities for detection and commercialization. The discussion of these results has led to the evidence that the endophyte can indeed be used as a plant growth promoter. The work also points to gaps in knowledge in several areas and emphasizes that further studies are needed. KW - Fungal endophyte KW - Metarhizium brunneum KW - Plant growth promoter KW - Metarhizium KW - Entomopathogenic fungi Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-14648 ER - TY - THES A1 - Kouis, Zacharias T1 - Photovoltaic power potential in Cyprus and how the synergies observed in an Agrivoltaic system affect the efficiency of food and energy production N2 - Cyprus plans to drastically increase its share of RES grid penetration from 16.7% in 2020 to 22.9% in 2030 by taking advantage of the sun’s energy abundance in the region and the favorable climatic conditions available. In this study, the solar potential of Cyprus through PV technology will be assessed and quantified with the use of PVGIS tool on three different levels: theoretical, practical and economical, while spatial representation of the region’s potential will allow for better comprehension of the concept. Land use constraints being a major limitation for the implementations of such concepts can be avoided with the dual use of land in a scheme known as Agrivoltaics. The coexistence of crop and energy production can give rise to synergies that affect the efficiency of such schemes. This paper using a qualitative approach will investigate and analyse these possible synergies and will identify barriers that might arouse. Results demonstrate yearly GHI and DNI values of 1963.62 kWh/m2 and 2201.61 kWh/m2 respectively, while yearly PVOUT accounts for 1828.75 kWh/kWp with a seasonality index of 1.4 and LCOE value of €0.053/kWh, evidencing undoubtedly the resource’s potential in the region. Within an agrivoltaic system nine categories of synergies where identified indicating an overall positive effect in the efficiency of food-energy nexus. The limpid representation of the PV energy resource potential in Cyprus and the comprehensive description of the arousing synergies can propel further exploitation of the agrivoltaic concept within the region. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-15707 ER - TY - THES A1 - Rümmele, Yvonne T1 - Advantages and disadvantages of mulching in market garden systems N2 - The need for sustainable and resilient food production is constantly increasing. Methods such as cover cropping, the use of mulches and non- or minimal tillage are recommended in large-scale agriculture, yet are not typically found in standard versions of market gardening, as developed by J.M. Fortier. In order to redesign the market gardening system towards more sustainability, the advantages and disadvantages of mulching, possible allelopathic effects from cover crops and mulches, and a possible on-site production of transfer and insitu mulch, were investigated. For this purpose, a literature review was carried out and afterwards a market garden rotation including cover crops was designed. The review results suggested that positive (crop-promoting) as well as negative (crop- and weed-reducing) allelopathy from cover crops exist and are includable into the system as a form of integrated weed management system. It was found that the advantages of mulching outweigh the disadvantages and that it is possible to redesign the market garden system towards more sustainability. KW - Market gardening KW - Allelopathy KW - Intercropping KW - Cover crops KW - Mulch Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:1383-opus4-17025 ER -