Browsing by Subject "Anbausystem"

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Developing cropping systems for the ancient grain chia (Salvia hispanica L.) in two contrasting environments in Egypt and Germany
(2020) Mack, Laura; Graeff-Hönninger, Simone
Chia (Salvia hispanica L.) seeds have been revived as functional “superfood” for human nourishment especially for vegan and vegetarian diets and are becoming increasingly widespread and present in new food products in Europe. The seeds are beneficial because of being gluten-free, containing antioxidants and a high concentration of α-linolenic acid, and having a high content of dietary fiber and high-quality protein. Chia is originally adapted to short-day conditions and grows naturally in tropical and subtropical environments. Nevertheless, it can survive under water stress and could, therefore, be cultivated in arid regions. Egypt has been classified as a water-scarce state. Due to its drought tolerance, chia might contribute to saving the scarce source “water” in Egypt and offer the chance to export these high value seeds, generating foreign exchange for reimporting e.g. wheat characterized by a higher water demand. Worldwide, the biggest problems and key challenges under climate change (CC) are water and food security in arid and semiarid regions. In the future, CC and water scarcity will significantly threaten agriculture and sustainable development. A rising population requires on the one hand an increase in food grain production, but also a change toward environmentally sound sustainable agriculture. Chia has been suggested as a favorably economic alternative for common field crops sustaining diversification and stabilization of the local agricultural economy. However, broad experience in growing chia in new environments is missing. The agronomic management has not been improved from formerly small-scale production systems. Most of the previous studies focused on seed characteristics. Information on fertilization, plant protection, and improved varieties is scarce, which are reasons for its low productivity in the countries of origin. Field experiments were conducted at the experimental station “Ihinger Hof” of the University of Hohenheim in southwestern Germany from 2015 to 2017 and in Egypt during the cropping season 2015 to 2016 at SEKEM’s experimental station located 50 km Northeast of Cairo. The present doctoral thesis was based on a project embedded in the graduate school Water-People-Agriculture (WPA) at the University of Hohenheim funded by the Anton-&-Petra-Ehrmann foundation that focuses on key water issues and water related challenges of todays society. On a final note, the main results of this thesis provide further information and expanded knowledge on chia cultivation in two contrasting environments (including a desert region) out of its center of origin. Overall, the current doctoral thesis presents a combined approach of experimental field research and crop modeling to support the optimization of farming practices of chia in new environments. A universal and nondestructive LA estimation model for chia was developed. Further, the CROPGRO model was adapted for chia to provide a preliminary model for a realistic simulation of crop growth variables. The approaches presented in this thesis may contribute to testing new environments for chia cultivation and to improving its production. Moreover, this study helped to develop further general model source codes to simulate the growth of tiny seeds. The adaptation to other Salvias should be much easier with this developed model. Future research requirements and issues requiring model improvement such as N-response and the development of code relationships that can simulate parameters of seed quality could improve the plant growth model for chia.
Participatory evaluation of sustainability of farming systems in the Philippines
(2010) Vilei, Sonja; Dabbert, Stephan
Forest cover in the Philippines has been greatly reduced in the past and slightly recovered since, estimated at around 24% of land surface currently. Small-scale farmers have to survive on small landholdings (2 ha on average and mostly under 5 ha), face insecure land tenure, and the high population density leaves little scope for gaining new agricultural land. Their farming systems continue to form an important part of their livelihoods, but often their strategies are unsustainable in the long run. While the need for evaluating common farming systems and compare them with new alternatives exists, it is important to involve local stakeholders in the search for suitable sustainability indicators. In this study, the search was based on the Sustainable Rural Livelihoods Framework and therefore organised under its five types of capital assets: natural, financial, physical, human and social capital. Farmers from five study sites along the Western side of the island of Leyte were gathered in eight focus group discussions to discuss the issues of success and sustainability of their farming systems and identify and rank possible criteria for an evaluation of sustainability. Nine other stakeholders from the same sites were interviewed individually. In a second research phase, all 49 identified criteria were given to 30 farmers and 18 other stakeholders for ranking. Three groups of farmers from the municipality of Baybay were used for comparison: one group of rice and coconut farmers; a second group with (additional) exotic timber trees (usually Gmelina and Acacia mangium); a third group with (additional) indigenous timber trees (?Rainforestation Farming?). The identified indicators were tested regarding their usefulness for comparing the three groups of farmers. Rainforestation Farming, as promising alternative farming system, was analysed further regarding financial aspects and its adoptability with regard to small-scale farmers. The Sustainable Rural Livelihoods Framework was useful for identifying suitable evaluation criteria. The importance of the five capital assets groups was perceived similarly by farmers and other stakeholders, but ranking results for single criteria (i.e. soil quality, membership in organisation) differed. The same holds true when comparing results for the four study regions, where the individual ranking was carried out: significant differences existed for single, mostly financial, criteria (i.e. record-keeping, investment costs) but not for importance of the five capital asset groups. The ranking results differed quite substantially, though, between focus groups and individual farmers, indicating on the one hand the influence of group leaders. But, on the other hand, farmers had the complete list of criteria for the individual ranking, including several criteria which they had not thought of previously, but which they still regard as important. Fifteen criteria were selected as indicators for comparing the three farmers groups. Rainforestation farmers were the group scoring significantly higher on most indicators (i.e education level adults and children, land available per capita, (perceived) soil quality, number of soil conservation measures used, membership in organisation) than farmers without timber trees. Farmers having planted exotic timber trees scored closer to Rainforestation farmers. But to be able to judge if the specific farming system leads to a more sustainable livelihood, time series data would have been necessary. The data of this study allowed concluding that tree farmers planting (indigenous or exotic) timber trees are endowed with higher resources ? more land, higher income, higher education levels. Most likely they had these resources before starting their farming systems. In addition, these farmers were also more actively engaged in organisations and had more contact to extension agents, therefore enhancing their social (and human) capital. The higher score regarding (perceived) soil quality and (non-) use of pesticides these farmers groups reached are likely to be an outcome of the farming system practiced. Analysing the financial feasibility and adoptability of Rainforestation Farming, it shows that the system has the potential to be profitable, but coming with a high risk: investment costs are very high and it takes up to 13 years to regain them. Consequently, the first adopters either had unused land areas or substantial off-farm income, and the subsequent adoption rate is low. Sustainability has to be understood as a dynamic and not a static concept and the concept of sustainable land management must consequently evolve as well. This study tried to add further findings regarding the use of suitable methods for this cause, but as already mentioned above, time series data would be necessary to assess the progress of farming systems towards ?sustainability?.
Sustainable bioenergy cropping concepts : optimizing biomass provision for different conversion routes
(2014) Mast, Benjamin; Claupein, Wilhelm
Today energy from biomass already contributes to a considerable share to the global energy consumption. In particular, certain modern bioenergy streams like biogas, biofuels for transportation etc., are of increasing relevance. However, several of the beneficial aspects, which were initially attributed to the utilization of today’s bioenergy, had to be relativized and the controversies regarding environmental and socio-economic drawbacks have, in the meanwhile, been on the rise. Alongside a shift to advanced conversion technologies, the improvement of bioenergy cropping systems towards a sustainable biomass provision is a key element of future bioenergy production. Against this background, the present thesis assessed various aspects in terms of biomass production, biomass provision and biomass conversion mainly addressing the two bioenergy streams – 2nd generation biofuels and biogas. For biogas, the thesis addresses aspects regarding the development of alternative cropping systems, the evaluation of novel crops for biogas purpose, and the assessment of regional biogas potentials using a crop growth model. The second focus of the thesis was set on biofuels while special attention was given to the production of microbial biodiesel, and the characterization and evaluation of potential feedstocks for this purpose.
The bioeconomy potential of hemp (Cannabis sativa L.) : challenges of new genotypes and cultivation systems to meet the rising demand for phytocannabinoids
(2021) Burgel, Lisa; Graeff-Hönninger, Simone
Cannabis sativa L. as a prime example of a multifunctional crop is excellently suited for recycling management due to its versatility and the usability of the whole plant. Cannabis currently experiences a boom due to its rich phytochemical repertoire, its fibres and valuable oil required in numerous products, and its unique agricultural properties. The medical benefits of C. sativa, based on the phytocannabinoids available in flowers and leaves, are the main focus of attention worldwide. Innovative markets in the food, cosmetics and pharma industry are growing fast, with a focus on cannabidiol (CBD), which is the leading cannabinoid of the cannabis plant. Basically, it is important to differentiate between industrial hemp genotypes and phytocannabinoid-rich (PCR) cannabis genotypes. Industrial hemp meet the 0.2% THC limit mandated by the EU legislation, and therefore, can be legally cultivated by farmers on a field scale. PCR genotypes contain high amounts of non-psychoactive cannabinoids such as CBD and cannabigerol (CBG) in the range of 10 – 30% while their THC content is also below 0.2%. These genotypes are currently being bred but are still barely available on the market. Cannabinoid extraction from industrial hemp cultivated on a field scale could provide a decisive advantage as the harvested biomass quantities could be significantly increased through better land use and cost management, compared to an indoor system. The multi-functionality of the industrial hemp can provide added economic value. Therefore, existing cultivation systems for fibre and oilseed production have to be modified as the harvesting time and harvested organ are expected to differ greatly from those of the present systems. In order to achieve this, publication I dealt with the objective, to determine the yield potential of different EU-registered hemp genotypes with regard to inflorescence and biomass yield as well as cannabinoid content, depending on genotype, growth stage and biomass fraction in an outdoor cultivation system. The cultivation of seven industrial hemp genotypes (Finola, Fédora17, Ferimon, Félina32, Futura75, USO 31 and Santhica27) was carried out in a two-year field experiment. Sampling of leaves and inflorescence, took place at four specific growth stages: vegetative leaf stage, bud stage, full-flowering stage, and seed maturity stage. Dry matter was recorded, and cannabinoids were analysed. The results indicated that the content of cannabinoids highly depended on the genotype and the growth stage. Thus, biomass and inflorescence yields must be considered for an optimized harvest result. Genotype Santhica27 indicated the highest contents of CBG/A. Further, it was found that genotypes such as Futura75, Fédora17, Félina32, Ferimon, Finola and Santhica27, which were highlighted to have a higher CBD/A or CBG/A content compared to other evaluated genotypes, reached the highest yields of threshing residues after seed maturity, and thus a higher CBD/A and CBG/A yield per area. In conclusion, harvesting after seed maturity seems to be economically beneficial. These findings make selected industrial hemp genotypes excellent candidates for multipurpose cropping. Additionally, the thesis aimed at further standardization of PCR genotypes in indoor cultivation systems. Due to the prescribed requirement of high-quality medical cannabis material, indoor cultivation is in focus as under the system all production parameters can be standardized. The production of cannabinoids under indoor conditions is expensive due to processing costs and regulatory limitations, thus there is an increasing interest in using the available space requirements efficiently. Publication II evaluated the adaptation of the plant architecture, through the targeted use of synthetic phytohormones, aiming for a small and compact plant morphology for various indoor systems. The objective was, to test the impact of exogenously applied plant growth regulators (PGRs), such as NAA, BAP and a mixture (NAA/BAP-mix) of both on the plant architecture of different PCR genotypes. Therefore, genotypes were treated with synthetic phytohormones in various concentrations in a greenhouse experiment. Furthermore, the differences in leaf and flower yields resulting from morphological changes in these genotypes and their CBD/A content was investigated. A genotype-specific impact of applied PGRs on the plant architecture was determined. NAA led to more compact plants with a consistently high floral yield for genotype KANADA, whereas CBD/A content was not affected. Genotypes 0.2x and FED showed reduced floral yields due to the PGRs applications. Publication III dealt with the evaluation of the growth performance of PCR genotypes grown in different substrate compositions substituted with peat alternatives in an indoor cultivation system. The impacts of the following substrate compositions: peat-mix growth media (PM); peat-mix substituted with 30% of green fibres (G30) consisting of coniferous wood and wood chips from pine and spruce wood growth media, and coco coir fibres (CC), on growth performance, biomass and flower yields, biomass nitrogen (N) content as well as CBD/A contents were tested. The results showed that the different substrates had significant impacts on the growth, biomass and floral yields, root development and N tissue content of the tested genotypes. A genotype-specific reaction on floral yield was investigated. While genotype KANADA had the highest floral yields when grown in PM, 0.2x showed no significant differences, with higher floral yields grown in G30 and CC. For both genotypes, no limiting effect on CBD/A content was enacted. It can be concluded, that organic peat alternatives such as green fibres, partly replacing peat in standard growing media, offers a genotype-specific option.