The fate of nitrogen during agricultural intensification in East Africa: nitrogen budgets in contrasting agroecosystems

Open Access ArticleThe intensification of agricultural systems in sub-Saharan Africa (SSA) is necessary to reduce poverty and improve food security, but increased nutrient applications in smallholder systems could have negative consequences for water quality, greenhouse gas emissions, and air quality. We tracked nitrogen (N) inputs and measured maize (Zea mays) biomass, grain yields, N leaching, and nitric oxide (NO) and nitrous oxide fluxes from a clayey soil in Yala, Kenya and a sandy soil in Tumbi, Tanzania, with application rates of 0, 50, 75, 100, 150, and 200 kg N ha−1 yr−1 over two cropping seasons. Maize yields were 4.5 times higher in Yala than Tumbi, but yields plateaued at both sites with fertilizer applications at or above 100 kg N ha−1 yr−1. Partial N budgets in Yala were typically negative, meaning more N was exported in maize biomass plus grain or lost from the system than was added in fertilizer. In Tumbi, N budgets were negative at lower fertilizer levels but positive at higher fertilizer levels. At both sites most (96%) of the N was lost through maize biomass/grain removal and N leaching. Fertilizer additions at or less than 50 kg N ha−1 yr−1 on these two contrasting sites resulted in minor gaseous N losses, and fertilizer additions less than 200 kg N ha−1 yr−1 caused relatively little change to N leaching losses. This indicates that the modest increases in fertilizer use required to improve maize yields will not greatly increase cropland N losses. Plain Language Summary Crop yields in smallholder agriculture across sub-Saharan Africa are low but could be increased by greater applications of nitrogen fertilizer. However, greater use of nitrogen fertilizer creates potential for higher emissions of nitrogen trace gases and nitrogen leaching losses. This study added nitrogen fertilizer doses (0, 50, 75, 100, 150, and 200 kg of nitrogen per hectare) to maize cropland in two smallholder farming sites, one on clay-rich soils in Kenya and one on sandy soils in Tanzania. It tracked removal of nitrogen fertilizer via harvested maize and losses as nitrous oxide (a greenhouse gas), NO (an air pollutant), and leaching of soil solution. Yields were 4.5 times higher on the clayey soil; yields plateaued at nitrogen application above 100 kg per hectare. Leaching losses far exceeded gaseous losses at both sites: 96% of nitrogen was removed in harvested crops and soil solution. Nitrogen additions at or below 50 kg of nitrogen per hectare led to minor increases in gaseous nitrogen losses and additions less than 200 kg of nitrogen per hectare did not increase soil solution losses. This indicates that the modest increases in fertilizer use required to improve maize yields will not greatly increase cropland nitrogen losses

The Climate Response to Emissions Reductions Due to COVID‐19: Initial Results From CovidMIP

Many nations responded to the corona virus disease-2019 (COVID-19) pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO2, other greenhouse gases and ozone and aerosol precursors. We present the initial results from a coordinated Intercomparison, CovidMIP, of Earth system model simulations which assess the impact on climate of these emissions reductions. 12 models performed multiple initial-condition ensembles to produce over 300 simulations spanning both initial condition and model structural uncertainty. We find model consensus on reduced aerosol amounts (particularly over southern and eastern Asia) and associated increases in surface shortwave radiation levels. However, any impact on near-surface temperature or rainfall during 2020–2024 is extremely small and is not detectable in this initial analysis. Regional analyses on a finer scale, and closer attention to extremes (especially linked to changes in atmospheric composition and air quality) are required to test the impact of COVID-19-related emission reductions on near-term climate. © 2021. Crown Copyright. © 2021. Her Majesty the Queen in Right of Canada. This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland. Reproduced with the permission of the Minister of Environment and Climate Change Canada. This article has been contributed to by US Government employees and their work is in the public domain in the USA

A global research priority agenda to advance public health responses to fatty liver disease

Background & aims An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community. Methods Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy. Results The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of ‘agree’ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (‘agree’ + ‘somewhat agree’); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% ‘agree’), 13 priorities had 90% combined agreement. Conclusions Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health community’s efforts to advance and accelerate responses to this widespread and fast-growing public health threat. Impact and implications An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat

Current and future nitrous oxide emissions from African agriculture

Most emission estimates of the greenhouse gas nitrous oxide (N2O) from African agriculture at a continental scale are based on emission factors, such as those developed by the IPCC Guidelines. Here we present estimates from Africa from the EDGAR database, which is derived from the IPCC emission factors. Resulting estimates indicate that N2O emissions from agriculture represented 42% of total emissions from Africa (though that rises to 71% if all savannah and grassland burning is included), or roughly 6% of global anthropogenic N2O emissions (or 11% including burning). Emissions from African agriculture are dominated by grazing livestock; 74% of agricultural N2O excluding biomass burning was from paddocks, ranges, and pasture. Direct soil emissions represent 15% of agricultural emissions; substantial changes in direct emissions from North Africa helped drive a 47% continental increase in direct soil emissions from 1970 to 2005. Future trends based on the Millennium Ecosystem Assessment scenarios indicate that agricultural N2O emissions may double in Africa by 2050 from 2000 levels. Any regional or continental estimates for Africa are, however, necessarily limited by a paucity of direct measurements of emissions in sub-Saharan agro-ecosystems, and the heavy reliance on emission factors and other default assumptions about nitrogen cycling in African agriculture. In particular, a better understanding of livestock-related N inputs and N2O emissions will help improve regional and continental estimates. As fertilizer use increases in sub-Saharan Africa, emission estimates should consider several unusual elements of African agriculture: farmer practices that differ fundamentally from that of large scale farms, the long history of N depletion from agricultural soils, seasonal emission pulses, and emission factors that vary with the amount of N added

Wait, won't! want: Barriers to health care as perceived by medically and socially disenfranchised communities

Objectives. We explored barriers to healthcare as perceived by members of medically and socially disenfranchised communities. Methods. We conducted focus groups with 28 women and 32 men from Northeast Ohio who identified themselves as African-American, Hispanic/Latino, lesbian/gay/bisexual/transgendered, and/or Russian immigrant. Results. Participants described their experiences of waiting, things they won't tolerate, when they won't participate, and what they want from providers. They described behaviors, actions and relationship characteristics that they want from their providers and characteristics that they prefer in health systems. Conclusions. The themes of Wait, Won't, and Want have healthcare practice and policy implications. Patient-provider interactions are known to be significant determinants of healthcare outcomes and these exploratory findings suggest that they might also affect patient self-management strategies. Future efforts should focus on developing and testing patient-centered strategies that address the themes identified to increase engagement to increase self-management of health. © 2015, Southern Public Administration Education Foundation, Inc. All rights reserved