Fakultät Agrarwissenschaften

Permanent URI for this communityhttps://hohpublica.uni-hohenheim.de/handle/123456789/9

Die Fakultät entwickelt in Lehre und Forschung nachhaltige Produktionstechniken der Agrar- und Ernährungswirtschaft. Sie erarbeitet Beiträge für den ländlichen Raum und zum Verbraucher-, Tier- und Umweltschutz.

Homepage: https://agrar.uni-hohenheim.de/

Browse

Now showing 1 - 4 of 4

Long-term trends in yield variance of temperate managed grassland
(2023) Macholdt, Janna; Hadasch, Steffen; Macdonald, Andrew; Perryman, Sarah; Piepho, Hans-Peter; Scott, Tony; Styczen, Merete Elisabeth; Storkey, Jonathan; Macholdt, Janna; Professorship of Agronomy, Institute of Agriculture and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany; Hadasch, Steffen; Biostatistics Unit, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany; Macdonald, Andrew; Protecting Crops and Environment, Rothamsted Research, Harpenden, UK; Perryman, Sarah; Computational and Analytical Sciences Department, Rothamsted Research, Harpenden, UK; Piepho, Hans-Peter; Biostatistics Unit, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany; Scott, Tony; Protecting Crops and Environment, Rothamsted Research, Harpenden, UK; Styczen, Merete Elisabeth; Section of Environmental Chemistry and Physics, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark; Storkey, Jonathan; Protecting Crops and Environment, Rothamsted Research, Harpenden, UK
The management of climate-resilient grassland systems is important for stable livestock fodder production. In the face of climate change, maintaining productivity while minimizing yield variance of grassland systems is increasingly challenging. To achieve climate-resilient and stable productivity of grasslands, a better understanding of the climatic drivers of long-term trends in yield variance and its dependence on agronomic inputs is required. Based on the Park Grass Experiment at Rothamsted (UK), we report for the first time the long-term trends in yield variance of grassland (1965–2018) in plots given different fertilizer and lime applications, with contrasting productivity and plant species diversity. We implemented a statistical model that allowed yield variance to be determined independently of yield level. Environmental abiotic covariates were included in a novel criss-cross regression approach to determine climatic drivers of yield variance and its dependence on agronomic management. Our findings highlight that sufficient liming and moderate fertilization can reduce yield variance while maintaining productivity and limiting loss of plant species diversity. Plots receiving the highest rate of nitrogen fertilizer or farmyard manure had the highest yield but were also more responsive to environmental variability and had less plant species diversity. We identified the days of water stress from March to October and temperature from July to August as the two main climatic drivers, explaining approximately one-third of the observed yield variance. These drivers helped explain consistent unimodal trends in yield variance—with a peak in approximately 1995, after which variance declined. Here, for the first time, we provide a novel statistical framework and a unique long-term dataset for understanding the trends in yield variance of managed grassland. The application of the criss-cross regression approach in other long-term agro-ecological trials could help identify climatic drivers of production risk and to derive agronomic strategies for improving the climate resilience of cropping systems.
Perceived effects of farm tractors in four African countries, highlighted by participatory impact diagrams
(2020) Daum, Thomas; Adegbola, Ygué Patrice; Kamau, Geoffrey; Kergna, Alpha Oumar; Daudu, Christogonus; Zossou, Roch Cedrique; Crinot, Géraud Fabrice; Houssou, Paul; Mose, Lawrence; Ndirpaya, Yarama; Wahab, A. A.; Kirui, Oliver; Oluwole, Fatunbi Abiodun
Agricultural mechanization is on the rise in Africa. A widespread replacement of manual labor and animal traction will change the face of African agriculture. Despite this potentially transformative role, only a few studies have looked at the effects of mechanization empirically, mostly focusing on yields and labor alone. This is the first paper that explores perceived agronomic, environmental, and socioeconomic effects together, thereby revealing linkages and trade-offs, some of which have been hitherto unknown. Data were collected using a novel data collection method called “participatory impact diagrams” in four countries: Benin, Kenya, Nigeria, and Mali. In 129 gendered focus group discussions, 1330 respondents from 87 villages shared their perceptions on the positive and negative effects of agricultural mechanization, and developed causal impact chains. The results suggest that mechanization is likely to have more far-reaching agronomic, environmental, and socioeconomic consequences than commonly assumed. Most perceived effects were positive, suggesting that mechanization can help to reduce poverty and enhance food security but other effects were negative such as deforestation, soil erosion, land-use conflicts, and gender inequalities. Accompanying research and policy efforts, which reflect variations in local agro-ecological and socioeconomic conditions, are needed to ensure that mechanization contributes to an African agricultural transformation that is sustainable from a social, economic, and environmental perspective.
Proposal and extensive test of a calibration protocol for crop phenology models
(2023) Wallach, Daniel; Palosuo, Taru; Thorburn, Peter; Mielenz, Henrike; Buis, Samuel; Hochman, Zvi; Gourdain, Emmanuelle; Andrianasolo, Fety; Dumont, Benjamin; Ferrise, Roberto; Gaiser, Thomas; Garcia, Cecile; Gayler, Sebastian; Harrison, Matthew; Hiremath, Santosh; Horan, Heidi; Hoogenboom, Gerrit; Jansson, Per-Erik; Jing, Qi; Justes, Eric; Kersebaum, Kurt-Christian; Launay, Marie; Lewan, Elisabet; Liu, Ke; Mequanint, Fasil; Moriondo, Marco; Nendel, Claas; Padovan, Gloria; Qian, Budong; Schütze, Niels; Seserman, Diana-Maria; Shelia, Vakhtang; Souissi, Amir; Specka, Xenia; Srivastava, Amit Kumar; Trombi, Giacomo; Weber, Tobias K. D.; Weihermüller, Lutz; Wöhling, Thomas; Seidel, Sabine J.; Wallach, Daniel; Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany; Palosuo, Taru; Natural Resources Institute Finland (Luke), Helsinki, Finland; Thorburn, Peter; CSIRO Agriculture and Food, Brisbane, Australia; Mielenz, Henrike; Institute for Crop and Soil Science, Julius Kühn Institute (JKI) – Federal Research Centre for Cultivated Plants, Braunschweig, Germany; Buis, Samuel; INRAE, UMR 1114 EMMAH, Avignon, France; Hochman, Zvi; CSIRO Agriculture and Food, Brisbane, Australia; Gourdain, Emmanuelle; ARVALIS - Institut du végétal Paris, Paris, France; Andrianasolo, Fety; ARVALIS - Institut du végétal Paris, Paris, France; Dumont, Benjamin; Plant Sciences & TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, University of Liege, Gembloux, Belgium; Ferrise, Roberto; Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy; Gaiser, Thomas; Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany; Garcia, Cecile; ARVALIS - Institut du végétal Paris, Paris, France; Gayler, Sebastian; Institute of Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Stuttgart, Germany; Harrison, Matthew; Tasmanian Institute of Agriculture, University of Tasmania, Launceston, Tasmania, Australia; Hiremath, Santosh; Aalto University School of Science, Espoo, Finland; Horan, Heidi; CSIRO Agriculture and Food, Brisbane, Australia; Hoogenboom, Gerrit; Global Food Systems Institute, University of Florida, Gainesville, USA; Jansson, Per-Erik; Royal Institute of Technology (KTH), Stockholm, Sweden; Jing, Qi; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Canada; Justes, Eric; PERSYST Department, CIRAD, Montpellier, France; Kersebaum, Kurt-Christian; Tropical Plant Production and Agricultural Systems Modelling (TROPAGS), University of Göttingen, Göttingen, Germany; Launay, Marie; INRAE, US 1116 AgroClim, Avignon, France; Lewan, Elisabet; Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden; Liu, Ke; Tasmanian Institute of Agriculture, University of Tasmania, Launceston, Tasmania, Australia; Mequanint, Fasil; Institute of Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Stuttgart, Germany; Moriondo, Marco; CNR-IBE, Firenze, Italy; Nendel, Claas; Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Padovan, Gloria; Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy; Qian, Budong; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Canada; Schütze, Niels; Institute of Hydrology and Meteorology, Chair of Hydrology, Technische Universität Dresden, Dresden, Germany; Seserman, Diana-Maria; Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany; Shelia, Vakhtang; Global Food Systems Institute, University of Florida, Gainesville, USA; Souissi, Amir; Swift Current Research and Development Centre, Agriculture and Agri-Food Canada, Swift Current, Canada; Specka, Xenia; Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany; Srivastava, Amit Kumar; Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany; Trombi, Giacomo; Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy; Weber, Tobias K. D.; Faculty of Organic Agriculture, Soil Science Section, University of Kassel, Witzenhausen, Germany; Weihermüller, Lutz; Institute of Bio- and Geosciences - IBG-3, Agrosphere, Forschungszentrum Jülich GmbH, Jülich, Germany; Wöhling, Thomas; Lincoln Agritech Ltd., Hamilton, New Zealand; Seidel, Sabine J.; Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany
A major effect of environment on crops is through crop phenology, and therefore, the capacity to predict phenology for new environments is important. Mechanistic crop models are a major tool for such predictions, but calibration of crop phenology models is difficult and there is no consensus on the best approach. We propose an original, detailed approach for calibration of such models, which we refer to as a calibration protocol. The protocol covers all the steps in the calibration workflow, namely choice of default parameter values, choice of objective function, choice of parameters to estimate from the data, calculation of optimal parameter values, and diagnostics. The major innovation is in the choice of which parameters to estimate from the data, which combines expert knowledge and data-based model selection. First, almost additive parameters are identified and estimated. This should make bias (average difference between observed and simulated values) nearly zero. These are “obligatory” parameters, that will definitely be estimated. Then candidate parameters are identified, which are parameters likely to explain the remaining discrepancies between simulated and observed values. A candidate is only added to the list of parameters to estimate if it leads to a reduction in BIC (Bayesian Information Criterion), which is a model selection criterion. A second original aspect of the protocol is the specification of documentation for each stage of the protocol. The protocol was applied by 19 modeling teams to three data sets for wheat phenology. All teams first calibrated their model using their “usual” calibration approach, so it was possible to compare usual and protocol calibration. Evaluation of prediction error was based on data from sites and years not represented in the training data. Compared to usual calibration, calibration following the new protocol reduced the variability between modeling teams by 22% and reduced prediction error by 11%.
Sanitized human urine (Oga) as a fertilizer auto-innovation from women farmers in Niger
(2021) Moussa, Hannatou O.; Nwankwo, Charles I.; Aminou, Ali M.; Stern, David A.; Haussmann, Bettina I. G.; Herrmann, Ludger
Poor soil chemical fertility and climate change restrict pearl millet grain yield in Niger Republic. Apart from the seedball technology, which targets majorly early phosphorus supply to the plants, the recommended practices of mineral fertilization and seed treatments (coating and priming) are barely affordable to the local farmers in particular. In the case of female farmers, who usually have chemically infertile farmlands often located far away from their homestead, low pearl millet grain yield can be exacerbated. In quest for a cheap, affordable, and effective solution, we hypothesized that the application of sanitized human urine (Oga), in combination with organic manure (OM) or solely, increases pearl millet panicle yield in women’s fields and on different local soils. In on-farm large-N trials (N = 681) with women farmers in two regions of Niger (Maradi, Tillabery), pearl millet panicle yields were compared between the control (farmer practice), and a combination of Oga and OM in the first and second year, and Oga alone in the third year. Our results showed an average panicle yield increase of about +30%, representing +200 to +300 kg ha−1. Major factors determining the yield effect are season, village, and local soil type. This study shows for the first time that Oga innovation can be used to increase pearl millet panicle yield particularly in the low fertile soils of women’s farmlands in Niger. Oga innovation is affordable, locally available, and does not pose a risk to resource-poor female farmers of Niger.

Browse

Browsing Fakultät Agrarwissenschaften by Journal "Agronomy for sustainable development"