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AbstractClimate change strongly affects the health of sub-Saharan African populations. Effective adaptation strategies are required in order to enhance their limited adaptive capacities. The DFG-funded Research Unit (RU) “Climate change and health in sub-Saharan Africa” unites nine research institutions from Burkina Faso, Kenya, Germany, and Switzerland that will design, implement, and evaluate four different adaptation projects in these two African countries from 2020 until 2022.First, the effectiveness of an agro-biodiversification and nutrition program will be established for the reduction of child undernutrition of climate-sensitive nutrients in rural Burkina Faso and Kenya. Two respective cluster-randomized controlled trials (cRCT) will be conducted, each consisting of 2 × 600 children. Second, another cRCT will be conducted among 2 × 300 households in rural Burkina Faso to investigate how sunlight-reflecting cool-roof coatings affect human health outcomes, including cardiovascular and heat-related outcomes. Further outcomes comprise indoor temperature, carbon footprint, and productivity. Third, an index-based weather insurance (IBWI) will be introduced in rural Burkina Faso. The effects of IBWI on childhood nutritional status, dietary behavior, and healthcare seeking will be determined in 2 × 20 villages. Fourth, microbial larviciding has been evaluated as a promising environmental control for malaria vectors in Burkina Faso. Here, the interactions between climatic factors and the effectiveness of the intervention will be tested using spatiotemporal models.

AbstractProcess‐based models are useful for assessing the impact of changing management practices and climate on yields and greenhouse gas (GHG) emissions from agricultural systems such as grasslands. They can be used to construct national GHG inventories using a Tier 3 approach. However, accurate simulations of nitrous oxide (N2O) fluxes remain challenging. Models are limited by our understanding of soil‐plant‐microbe interactions and the impact of uncertainty in measured input parameters on simulated outputs. To improve model performance, thorough evaluations against in situ measurements are needed. Experimental data of N2O emissions under two management practices (control with typical fertilization versus increased clover and no fertilization) were acquired in a Swiss field experiment. We conducted a multimodel evaluation with three commonly used biogeochemical models (DayCent in two variants, PaSim, APSIM in two variants) comparing four years of data. DayCent was the most accurate model for simulating N2O fluxes on annual timescales, while APSIM was most accurate for daily N2O fluxes. The multimodel ensemble average reduced the error in estimated annual fluxes by 41% compared to an estimate using the Intergovernmental Panel on Climate Change (IPCC)‐derived method for the Swiss agricultural GHG inventory (IPCC‐Swiss), but individual models were not systematically more accurate than IPCC‐Swiss. The model ensemble overestimated the N2O mitigation effect of the clover‐based treatment (measured: 39–45%; ensemble: 52–57%) but was more accurate than IPCC‐Swiss (IPCC‐Swiss: 72–81%). These results suggest that multimodel ensembles are valuable for estimating the impact of climate and management on N2O emissions.

AbstractIntraspecific variation in genotypically determined traits can influence ecosystem processes. Therefore, the impact of climate change on ecosystems may depend, in part, on the distribution of plant genotypes. Here we experimentally assess effects of climate warming and excess nitrogen supply on litter decomposition using 12 genotypes of a cosmopolitan foundation species collected across a 2100 km latitudinal gradient and grown in a common garden. Genotypically determined litter‐chemistry traits varied substantially within and among geographic regions, which strongly affected decomposition and the magnitude of warming effects, as warming accelerated litter mass loss of high‐nutrient, but not low‐nutrient, genotypes. Although increased nitrogen supply alone had no effect on decomposition, it strongly accelerated litter mass loss of all genotypes when combined with warming. Rates of microbial respiration associated with the leaf litter showed nearly identical responses as litter mass loss. These results highlight the importance of interactive effects of environmental factors and suggest that loss or gain of genetic variation associated with key phenotypic traits can buffer, or exacerbate, the impact of global change on ecosystem process rates in the future.

Although plant-based culture media enhances in vitro cultivation of rhizobacteria, studies assessing their biomass potential for large-scale applications are lacking. Here, we advance plant pellets (PPs) as a novel technology to unlock the potential of such vegan culture media for biomass production of Rhizobium leguminosarum. PP formulations were based on mixtures of Egyptian clover powder and the agro-byproducts glycerol and molasses. These mixtures were either contained or not contained in teabags during culture media preparation. Metrics of biomass included colony forming units, optical density (OD600nm), and cell dry weight (DW). Biomass comparisons between culture media based on PPs and standard yeast extract mannitol (YEM) revealed that the following PPs composition, contained in teabags, cultivated rhizobia at levels comparable to YEM: 16 g clover powder, 5% molasses, and 0.8% glycerol. This PPs composition enabled shorter generation times of rhizobia (PP: 3.83 h, YEM: 4.28 h). Strikingly, PPs mixtures supplemented with 10% molasses and not contained in teabags promoted rhizobia without apparent lag phases and produced 25% greater DW than YEM. PPs potentiate the use of dehydrated vegan feedstocks for both plant microbiota cultivation and biomass production and appear as cost- and labor-effective tools, easy to handle and store for plant-based culture media preparation.

This conceptual paper aims to expand the notion of “farming newcomers” in Europe by also including those that we label “involuntary newcomers”, who correspond to the workforce coming unwillingly to farming for reasons associated with spatial (im)mobilities. We fully develop our aim in four steps. Firstly, we present an integrative literature review which describes how the interplay between the key concepts of the sustainable farming framework (i.e., sustained development, networked rural development, and spatial (im)mobilities) tailor the newcomers’ arrival to the farming sector. Secondly, we define involuntary newcomers, describe their profiles and list the barriers to their engagement with sustainable farming. Thirdly, we advance some implications and limitations of our work for mobility research agendas. Fourthly, we conclude with an overview of the main inputs provided by our paper. We contribute to the literature by showing that: (a) newcomers must be defined beyond land ownership; (b) involuntary newcomers are very diverse, due to trends in spatial (im)mobilities; and (c) there is a high risk of the sustainable farming framework failing to meet its ambitions if it continues to ignore involuntary newcomers (and the barriers they encounter) in sustainable forms of agriculture.

Grassland biomass is suitable in numerous ways for producing energy. It is well established as feedstock for biogas production. The aim of this review is to summarize current knowledge on suitability and sustainability of grassland biomass for anaerobic digestion. In the first section grassland management for biogas feedstock as well as specifics of harvest, postharvest and digestion technology are described. Methane yields from grass are influenced by many factors. While the effects of some parameters such as grass species, cutting period and management intensity can be regarded as well known, other parameters such as preservation and processing still need investigation. In the second section economic aspects and environmental impacts are discussed. Profitability can be achieved depending on grass silage supply costs and the concept of anaerobic digestion and energy use. Grassland biomass for biogas production competes with other feedstock and other forms of grassland use, in particular animal husbandry. In developed countries a growing production of milk and meat is achieved with decreasing ruminant numbers, resulting in an increasing amount of surplus grassland with a remarkable bioenergy potential. In emerging and developing countries a rapidly rising demand for and production of milk and meat induce growing pressure on grasslands, so that their use for animal feed presumably will take priority over use for bioenergy. Grasslands provide a variety of essential environmental benefits such as carbon storage, habitat function, preservation of ground and surface water quality. When producing biogas from grassland these benefits will remain or even grow, providing appropriate grassland management is implemented. In particular, greenhouse gas emissions can be considerably reduced.