Agricultural Greenhouse Gases from Sub-Saharan Africa

Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use.The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011).

<p>Agricultural greenhouse gas (GHG) emissions in Africa contribute 15 % to the global total agricultural emissions, which is in the same range as agricultural emissions from Europe. The majority of these agricultural GHG emissions is attributed to livestock farming (up to 80 % at national scale), of which 10-25 % originate from livestock manure. At the same time, livestock production is essential for the livelihoods of millions of people in Sub-Saharan Africa (SSA), where 45-80 % of livestock production occurs in smallholder systems. With the growing population in SSA, the demand for livestock products is expected to increase, and – without low-emission manure management – a rise in manure-borne GHG emissions will occur. However, reliable <em>in situ</em> measurements from SSA are scarce, leading to substantial uncertainties in agricultural GHG budgets and making assessments of potential mitigation options difficult.</p><p>Here we present results from two cattle manure incubation experiments in Kenya, using manure from Boran (<em>Bos indicus</em>) cattle, a breed common in East Africa that were fed with typical feeds used in SSA smallholder farms. Manure was collected and piled in heaps (solid storage), the most common form of manure storage in Kenyan smallholder systems, and CH<sub>4</sub> and N<sub>2</sub>O emissions were measured over 140 days. In the first trial, cattle were fed a diet that either met their maintenance-energy requirements (i.e. animals received enough food to support their metabolism), or a diet at sub-maintenance energy levels to simulate common conditions in smallholder farming systems, particularly during the dry seasons. Cumulative manure N<sub>2</sub>O emissions from the sub-maintenance diet (i.e. the “hungry” cows) were lower than from cattle fed at maintenance energy levels. These lower N<sub>2</sub>O emission likely resulted from lower N concentration and a wider C:N ratio in the manure than in the “better fed” animals. Furthermore, the urine-N:faecal-N ratio in the “hungry” cows decreased, indicating a shift from urine-N (mostly inorganic N) to faecal-N (mostly organic N), which further backs the lower observed N<sub>2</sub>O emissions. Both N<sub>2</sub>O as well as CH<sub>4</sub> emissions from manure were lower than the IPCC default emission factors for solid storage in tropical regions across all diets tested.</p><p>In the second trial, Boran cattle were fed with three different tropical forage grasses common in Kenya: Napier (<em>Pennisetum purpureum</em>), Rhodes (<em>Gloris gayana</em>), and Brachiaria (<em>Brachiaria brizantha</em>). Manure from the Rhodes grass diet had the lowest N concentration and also the lowest cumulative CH<sub>4</sub> emissions, while N<sub>2</sub>O emissions did not differ between diets. Similar to the sub-maintenance feeding trial, total CH<sub>4</sub> and N<sub>2</sub>O emissions were lower than the IPCC default factors. Taken together, these results are an important step towards reducing the uncertainties in GHG emissions from agriculture in SSA. Furthermore, if African nations use IPCC default values for their national GHG reporting on livestock, emissions are likely to be overestimated, highlighting the importance and benefits of localized data from Africa.</p>

Development strategies increasingly emphasize agricultural development, employment, and equity; it is therefore important to examine the role of education in light of these new emphases. The purpose of this paper is to synthesize the conclusions of a number of studies of the effect of a farmer's educational level and exposure to extension services on his productivity. Eighteen studies conducted in low-income countries provided 37 sets of farm data that allow a statistical estimation of the effect of education. The overall conclusion of this paper is that farm productivity increases as a result of a farmer's completing at least 4 additional years of elementary education rather than none. Also, the effects of education were much more likely to be positive in modernizing agricultural environments than in traditional ones.

Globally, agriculture is directly responsible for 14% of annual greenhouse gas(GHG) emissions and induces an additional 17% through land use change, mostlyin developing countries (Vermeulen et al 2012). Agricultural intensification andexpansion in these regions is expected to catalyze the most significant relativeincreases in agricultural GHG emissions over the next decade (Smith et al 2008,Tilman et al 2011). Farms in the developing countries of sub-Saharan Africa andAsia are predominately managed by smallholders, with 80% of land holdingssmaller than ten hectares (FAO 2012). One can therefore posit that smallholderfarming significantly impacts the GHG balance of these regions today and willcontinue to do so in the near future.However, our understanding of the effect smallholder farming has on theEarth’s climate system is remarkably limited. Data quantifying existing andreduced GHG emissions and removals of smallholder production systems areavailable for only a handful of crops, livestock, and agroecosystems (Herrero et al2008, Verchot et al 2008, Palm et al 2010). For example, fewer than fifteenstudies of nitrous oxide emissions from soils have taken place in sub-SaharanAfrica, leaving the rate of emissions virtually undocumented. Due to a scarcity ofdata on GHG sources and sinks, most developing countries currently quantifyagricultural emissions and reductions using IPCC Tier 1 emissions factors.However, current Tier 1 emissions factors are either calibrated to data primarilyderived from developed countries, where agricultural production conditions aredissimilar to that in which the majority of smallholders operate, or from data thatare sparse or of mixed quality in developing countries (IPCC 2006). For the mostpart, there are insufficient emissions data characterizing smallholder agricultureto evaluate the level of accuracy or inaccuracy of current emissions estimates.Consequentially, there is no reliable information on the agricultural GHG budgetsfor developing economies. This dearth of information constrains the capacity totransition to low-carbon agricultural development, opportunities for smallholdersto capitalize on carbon markets, and the negotiating position of developingcountries in global climate policy discourse.Concerns over the poor state of information, in terms of data availability andrepresentation, have fueled appeals for new approaches to quantifying GHGemissions and removals from smallholder agriculture, for both existing conditionsand mitigation interventions (Berry and Ryan 2013, Olander et al 2013).Considering the dependence of quantification approaches on data and the currentdata deficit for smallholder systems, it is clear that in situ measurements must bea core part of initial and future strategies to improve GHG inventories and

The study discusses use of indigenous knowledge as a strategy for climate change adaptation among farmers in sub-Saharan Africa. The local farmers in this region through the indigenous knowledge systems have developed and implemented extensi ve adaptation strategies that have enabled them reduce vulnerability to climate variability and change over the years. However, this knowledge is rarely taken into consideration in the design and implementation of modern mitigation and adaptation strategie s. This paper highlights some indigenous adaptation strategies that have been practiced in sub Saharan Africa and the benefits of integrating such indigenous knowledge into formal climate change adaptation strategies. The study recommends the need to incor porate indigenous knowledge into climate change policies that can lead to the development of effective adaptation strategies that are cost -effective, participatory and sustainable.

Specific practices of conservation agriculture (CA) in sub-Saharan Africa are diverse and vary according to local farming conditions. However, despite more than two decades of investment in its development and dissemination, adoption of CA is low. Crop responses to CA are highly variable, and not always positive, which is an important hindrance for adoption, especially for resource-poor farmers who need immediate returns with their investments in CA in order to be able to feed their families. In contrast with commercial farms such as in Brazil, reduced costs with CA on smallholder farms in sub-Saharan Africa are not always observed. Another major challenge with the practice of CA is the use of crop residues for mulching since crop residues are a major source of feed for livestock, especially in semiarid regions, where biomass production is limited and livestock plays a crucial role in farming systems. Studies indicate that the three principles of CA, including mulching, are needed to increase crop yields compared with conventional tillage (CT)-based practices. Among the three principles of CA, mulching is certainly the one that is least observed in past and current cropping practices in Africa. CA has a potential to improve the soil water balance and increase soil fertility, and it is undoubtedly a cropping practice that can result in substantial benefits for certain farmers in Africa. The question is when and how it is the best approach for smallholder farmers in sub-Saharan Africa. In general, CA is more likely to be attractive for farmers with a strategy of intensification than for farmers who struggle to produce food for their family. The latter too often face multiple constraints that limit the possibilities to engage in technological innovations. Some farmers may not be interested in new technologies because they earn their income from off-farm activities. Good markets of input supply and sale of extra produce are a prerequisite condition for adoption of CA as they are for any other new agricultural technology that aims at intensification. In sub-Saharan Africa, there is certainly a need to better target CA to potential end users and adapt the CA practices to their local circumstances and specific farming contexts.

Blue revolution for food security under carbon neutrality: A case from the water-saving and drought-resistance rice

Agricultural greenhouse gas emissions on the planet threaten both food security and climate change. The United Nations is calling for food security and sustainable agriculture to end hunger by 2030. Sustainable Development Goal 2.4 addresses resilient agricultural practices to combat climate change and produce sustainable food. Resilient agricultural practices are only possible with agricultural technologies (AgriTech) that will create a digital transformation in agriculture. AgriTech can meet the increasing food demand by increasing production efficiency while increasing resource efficiency by combating problems such as climate change and water scarcity. The aim of this study is to examine the impacts of AgriTech usage on sustainable agriculture in Sub-Saharan African (SSA) countries. The analyses were conducted using panel data from 20 SSA countries between 2000 and 2022. In this study, MMQR (Method of Moments Quantile Regression) provided consistent results across quantiles in variable interactions, while GMM (Generalized Method of Moments) and KRLS (Kernel Regularized Least Squares Method) approaches were used to ensure consistency of results. The findings confirm that AgriTech (ATECH) and agricultural value added (AGRW) contribute significantly to sustainable agriculture in SSA countries. The coefficients of ATECH and AGRW variables are negative and statistically significant in all quantiles. This shows that when AgriTech use and agricultural value added increase in SSA, emissions from agriculture decrease and the environment improves. However, agricultural credits (ACRD) are insufficient to reduce agricultural emissions. Furthermore, agricultural workers (AEMP) and internet use (INT) help reduce agricultural emissions up to the 60th and 50th quantiles, while this effect disappears at higher quantile levels. These results emphasize the importance of integrating green procurement and green production technologies supported by green credits into agricultural production in order to achieve sustainable agricultural development goals in SSA. Policies that facilitate farmers' access to agricultural green credits should be adopted in SSA societies. Infrastructure works that will increase farmers' access to the internet should be increased. Awareness of agricultural workers on green production and sustainability should be provided to agricultural workers.Highlights. The results show that agricultural technologies, agricultural growth, agricultural labor, and internet use reduce agricultural emissions in SSAcountries, while credit use increases agricultural emissions. AgriTech use (ATECH) and agricultural value-added (AGRW) have statistically significant negative coefficients in all quantiles, indicating that increasing AgriTech and value-added reduce agricultural greenhouse gas emissions. The potential of AgriTech to reduce emissions is higher in low-emission quantiles (10-30%), while the effect is relatively weaker in high-emission quantiles. Agricultural credits (ACRD) only provide environmental improvements in the low-emission quantile (25%) and are insufficient to reduce emissions in high quantiles. Agricultural labor (AEMP) and internet use (INT) significantly reduced emissions at 10-50% quantiles, while this effect disappeared at higher quantiles. Farmers' success in reducing emissions is directly dependent on their internet access. Panel instantaneous momentum quantile regression (MMQR) was preferred to capture heterogeneous interactions, and the robustness of the results was confirmed with the GMM and KRLS approaches.

Comprehending the spatial-temporal characteristics, contributions, and evolution of driving factors in agricultural non-CO2 greenhouse gas (GHG) emissions at a macro level is pivotal in pursuing temperature control objectives and achieving China's strategic goals related to carbon peak and carbon neutrality. This study employs the Intergovernmental Panel on Climate Change (IPCC) carbon emissions coefficient method to comprehensively evaluate agricultural non-CO2 GHG emissions at the provincial level. Subsequently, the contributions and spatial-temporal evolution of six driving factors derived from the Kaya identity were quantitatively explored using the Logarithmic Mean Divisia Index (LMDI) and Geographical and Temporal Weighted Regression (GTWR) methods. The results revealed that the distribution of agricultural non-CO2 GHG emissions is shifting from the central provinces to the northwest regions. Moreover, the dominant driving factors of agricultural non-CO2 GHG emissions were primarily economic factor (EDL) with positive impact (cumulative promotion is 2939.61 million metric tons (Mt)), alongside agricultural production efficiency factor (EI) with negative impact (cumulative reduction is 2208.98 Mt). Influence of EDL diminished in the eastern coastal regions but significantly impacted underdeveloped regions such as the northwest and southwest. In the eastern coastal regions, EI gradually became the absolute dominant driver, demonstrating a rapid reduction effect. Additionally, a declining birth rate and rural-to-urban population migration have significantly amplified the driving effects of the population factor (RP) at a national scale. These findings, in conjunction with the disparities in geographic and socioeconomic development among provinces, can serve as a guiding framework for the development of a region-specific roadmap aimed at reducing agricultural non-CO2 GHG emissions.

Agriculture sector is one of major sources of income and livelihood to many populations of Sub-Saharan Africa (SSA). Over the past years animal production has been playing a vital role not only in generating revenues to farmers but also as a source of high qualitative proteins and essential micronutrients (i.e iron, zinc and vitamins) and boosting the agricultural productivity due to its importance in farmyards organic fertilization (i.e manure). Livestock production and Milk market in SSA are dominated by smallholder dairy farming (SDF) which employ nearly 70% of all livestock farmers. Despite its positive impact on people and SSA countries’ economy, SDF has been the major fastest growing agricultural contributors of GHG emissions such as CH4, N2O and CO2 (i.e 9t CO2e per tonne of milk; the highest in the world compared to other regions) thus accelerating global warming effect.Although several articles have investigated the impacts of livestock production on climate change, to the best of our knowledge the existing literature doesn’t contain any studies that provide insight review of smallholder dairy farming’s carbon footprint (CF) in SSA. This review paper is therefore aimed at critical analysis of current knowledge in terms of CF of smallholder dairy farming in SSA and effective mitigation strategies (dietary, manure and animal management) recently proposed to reduce CH4 and N2O emissions from ruminants. SSA was selected because of rapid rise of SDF in the region therefore it is expected to rapidly increase its GHG emissions in future if no sustainable measures are taken.The critical analysis, what is known and gaps in SDF from this review will help to inform the farmers, researchers, decision and policy makers interested in GHG emissions thus to provide the next direction in research and improvement of the sector for sustainability. Capacity building for raising awareness among farmers was identified as paramount to better understand the issue and the options to mitigate emissions on-farm. As longer as adaptation and mitigation strategies become paramount on national and regional agenda, SDF will make significant contribution to economies, improved livelihood and become sustainable livestock production systems in SSA at large.

Agriculture in Sub-Saharan Africa (SSA) is experiencing climate change-related effects that call for integrated regional assessments, yet capacity for these assessments has been low. The Agricultural Model Intercomparison and Improvement Project (AgMIP) is advancing research on integrated regional assessments of climate change that include climate, crop, and economic modeling and analysis. Through AgMIP, regional integrated assessments are increasingly gaining momentum in SSA, and multi-institutional regional research teams (RRTs) centered in East, West, and Southern Africa are generating new information on climate change impacts and adaptation in selected agricultural systems. The research in Africa is organized into four RRTs and a coordination team. Each of the RRTs in SSA is composed of scientists from the Consultative Group of International Agricultural Research (CGIAR) institutions, National Agriculture Research institutes (NARs), and universities consisting of experts in crop and economic modeling, climate, and information technology. Stakeholder involvement to inform specific agricultural systems to be evaluated, key outputs, and the representative agricultural pathways (RAPs), is undertaken at two levels: regional and national, in order to contribute to decisionmaking at these levels. Capacity building for integrated assessment (IA) is a key component that is undertaken continuously through interaction with experts in regional and SSA-wide workshops, and through joint creation of tools. Many students and research affiliates have been identified and entrained as part of capacity building in IA. Bi-monthly updates on scholarly publications in climate change in Africa also serve as a vehicle for knowledge-sharing. With 60 scientists already trained and actively engaged in IA and over 80 getting monthly briefs on the latest information on climate change, a climate-informed community of experts is gradually taking shape in SSA.

Climate change remains a global challenge, threatening food security and livelihoods,especially among smallholder farmers in sub-Saharan Africa (SSA). Recent estimates revealthat smallholder farmers account for 75% of the total agricultural output and 70% ofmarketed agricultural produce in Kenya. However, it is projected that climate change andvariability will reduce agricultural production by 10–20% by 2050. Climate changeadaptation strategies among smallholder farmers are thus critical to ensure the resilience ofpeople's livelihoods and the survival of agriculture. This systematic review examined climatechange adaptation strategies among smallholder farmers in sub-Saharan Africa. Thesynthesis included ten studies that met the criteria, including three quantitative and sevenmixed-methods studies. The quantitative studies identified significant climate adaptationstrategies included such as: adopting different seed/ plant varieties, changes in fertilizer andmanure use patterns, reducing runoff and erosion, and changes in crop sequences. Incontrast, the mixed methods studies revealed different significant climate adaptationstrategies such as planting trees, mulching, crop rotation, varying planting and harvestingdates, crop diversification, water harvesting, use of farmland manure, intercropping, andterracing. Key factors influencing the uptake of climate change adaptation strategies amongsmallholder farmers included increasingly challenging climate conditions, educationalattainment, and farming in higher potential agroecological environments. The reviewidentifies evidence gaps in optimizing the benefits from a unified approach to adaptationrather than separate treatment of adaptation or mitigation. Besides, despite adaptationstrategies being skewed towards integrated drought-related effects of climate change, thereview did not identify any gender-sensitive climate adaptation strategies reducing farmers'vulnerability to climate change impacts. There is a need for impact evaluations on the effectsof climate adaptation strategies, and further research on the effectiveness of climate changeadaptation strategies to examine both the extent to which these climate change adaptationstrategies interventions are transferrable to sub-Saharan countries.Keywords:Climate change, smallholder farmer, Adaptation strategies,Agricultural,Variability

Recent scientific evidence shows that crop yields in many Sub Saharan Africa (SSA) countries are likely to be severely affected by climate change. Reliance on rainfall in this region increases the vulnerability of cereal systems to climate change and variability. In large parts of SSA, maize (Zea mays L.) is the principal staple crop, covering a total of nearly 27 M ha, and yet maize yields remain the lowest in the world, stagnated at less than 2 Mg ha−1. Calculated and simulated analyses for SSA show that crop yields will decline by more than 10 % by 2055. The effect of climate change on crop yields is mainly attributed to: increased frequency of extreme events; effects of elevated CO2 (where studies project crop yield increases of 5–20 % at 550 ppm CO2); interactions of elevated CO2 with temperature and rainfall as well as with soil nutrients; and increased vulnerability to weed competition, insect pests, and diseases. However, several studies show that rainfall and water availability limit agricultural production more than temperature in SSA. The projected rainfall would increase by 2–4 % in Eastern Africa, but decrease by 5 % in Southern Africa during the main crop growing seasons. Temperatures are likely to increase throughout SSA by 2050, but the combination of increasing temperatures and low seasonal rainfall in Southern Africa suggest this region will be particularly vulnerable. Some of the crop models used for predicting the effect of climate change on yields are limited by their ability to predict effects of climatic events that lie outside the range of present-day variability. In addition, comparisons between models for the same setting have sometimes given differing results. This review paper shows that, for most of the SSA countries, the data required for assessing long-term effect of climate change on crop yield are lacking, that most of the models do not cater to assessment at the household level, and that no single approach can be considered as adequate. Therefore, a clear need exists for collaboration among different scientific disciplines for the development of agriculture in SSA in a changing climate.

Introduction: Climate change is a global phenomenon that is one of the key issues our globe faces in the twenty-first century to feed nine to ten billion people sustainably by 2050. It is a common and dynamic phenomenon caused by complex and interconnected physical, environmental, and human elements. Because it relies on agriculture and natural resources, warmer baseline conditions, low precipitation, and limited ability to adapt, Sub-Saharan Africa is regarded as the most vulnerable to the effects of climate change. Climate change affects and contributes significantly to food and agriculture. Sub-Saharan Africa is a rapidly developing region with a population of over 900 million people and a diverse ecological, meteorological, and cultural variety. It boasts the world's youngest and fastest-increasing population, and it is the only region where the rural population, particularly rural youth, will continue to expand past 2050. Methods: My systematic searches were based on past review methods, which included using database platforms or bibliographic databases such as Web of Science, Scopus, CAB abstracts, Science Direct, and JSTOR. I also ran a Google Scholar search. My searches were all restricted to Sub-Saharan Africa. As a result, I gathered all search results and reviewed all articles retrieved using preset inclusion criteria. I found over 50 publications, including key FAO and World Bank reports, that answered the highlighted problems. All articles were screened twice (title and abstract, then full-text), with consistency checks at each stage. Relevant publications were read critically, and meta-data and quantitative data were extracted and entered into a database. All included studies were reported narratively, and those that matched the meta-analysis requirements were presented descriptively. Review Findings: More than 80% of the research agreed that climate change and its implications are current problems in Sub-Saharan Africa. The majority of them forecast predicted changes in population numbers in Sub-Saharan Africa and the related demand for food, as well as examine major climate changes and explain how these changes may affect food production. Food demand in Sub-Saharan Africa is increasing due to socioeconomic and population growth. To increase food security and demand in the face of predicted demographic, economic, and environmental changes, aggressive measures are required. Although international food demand is expected to climb by 60% by 2050 compared to 2005/2007, the increase in Sub-Saharan Africa would be substantially bigger. Food prices in many Sub-Saharan African nations are rising faster than household incomes and other economic prospects. Food demand typically rises with urbanization as the population shifts from rural, presumably food-producing, to urban, primarily for food consumption. Conclusions: Sub-Saharan Africa has been identified as the most susceptible not only because of its significant exposure to severe climate change but also because many of its inhabitants cannot respond to or adapt to the effects of climate change. Over 90% of agriculture in Sub-Saharan Africa is rain-fed, and subsistence is neither technically nor financially robust enough to mitigate the negative effects of climate change, with little room for adaptation. As a result of this analysis, Sub-Saharan Africa is confirmed to be the most vulnerable region to climate change. As a result, governments and development organizations should focus on developing and implementing policies and programs that encourage farm-based adaptation techniques, and then they should be implemented and disseminated with farmers' participation.

Biochar is the carbon-rich soil amendment produced by the thermal decomposition (pyrolysis) of biomass. It attracted much interest because it contributes to sustainable soil fertility management and climate change mitigation. This paper reviews the potential impact of biochar on sustainable soil and crop productivity, carbon (C) sequestration and reduction of greenhouse gas (GHG) emissions. The unique characteristics of biochar, such as high surface area, surface charges, low bulk density, alkaline pH being recalcitrant to decomposition, high stability, and nutrient content are factors that enable it to sustainably improve soil and crop productivity and mitigate climate change. However, the pyrolysis technique, pyrolysis temperature and feedstock affect the characteristics and functions of biochar. Several studies have confirmed that biochar application improves soil properties such as soil porosity, structure and aggregation. It also enhances soil moisture holding capacity, pH, organic carbon (OC), CEC, total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), and reduces phosphorus (P) fixation (immobilization). The above characteristics of biochar and volatile organic compounds provide a conducive habitat for microbes, enhance microbial population and enzymatic activities as well as nitrogen mineralization. They also help microbes to perform their functions, including decomposing organic matter, recycling nutrients, preserving soil structure, and releasing plant nutrients. However, biochar is more effective in sustainably improving crop production and contributing to food security and mitigating climate change when it is integrated with compost and manure application. Biochar provides a stable and inert form of C sequestration for long-term with a minimum risk of its return into the atmosphere. It also reduces GHG emissions through reducing nutrient losses, retaining, and cycling nutrients, and improving nutrient use efficiency. Though smallholder farmers in Sub-Saharan Africa (SSA) can produce biochar from unused crop residues and leftover fruits for home garden agriculture, this technology needs to be incorporated into soil management policy and transformed into large-scale schemes through using large feedstocks, including invasive species, municipality wastes and industry biproducts.