In the last 40 years, large areas of the Mau forest, the largest contiguous tropical montane forest in East Africa, have been cleared for agriculture. To date, there are no empirical data on how this land use change affects carbon dioxide (CO 2 ) fluxes from soil respiration and soil methane (CH 4 ) fluxes. This study reports measured annual soil CO 2 and CH 4 fluxes from the native Mau forest and previously forested lands converted to smallholder grazing land, smallholder and commercial tea plantations and eucalyptus plantations. Fluxes were measured weekly from August 2015 to August 2016 using the static chamber method. Grazing lands had the highest (p = 0.028) cumulative respiratory CO 2 fluxes (25.6 ± 2.9 Mg CO 2 -C ha -1 year -1 ), whereas lowest fluxes were observed in commercial tea plantations (5.6 ± 0.5 Mg CO 2 -C ha -1 year -1 ). Soil respiratory CO 2 fluxes were ().,-volV) ( 01234567 89().,-volV) concentrations (p = 0.03). Annual soil CH 4 can be explained by mainly soil water content and bulk density and these factors are related to gas diffusion. Our study shows that converting tropical montane forests to managed land use types affects soil CO 2 and CH 4 fluxes. Specifically, the CH 4 sink strength in managed land use types of these montane tropical soils was reduced to less than half of the sink strength in the native forest. Soil respiratory CO 2 fluxes were also altered by land use with grazing lands emitting 3-4 times more CO 2 than the other land use types.

No abstract

CONTEXT The COVID-19 pandemic caused unprecedented global disruption and continues to wreak havoc. Dire predictions were made about the risks to smallholder farmers in lower- and middle- income, but hard data have been lacking. We present the results from 9201 interviews with smallholder farmers from seven countries. OBJECTIVE The objectives are to describe: i) how farmers perceive the key effects of the COVID-19 pandemic and containment measures on livelihoods and food security; ii) the effects on agricultural activities; iii) the coping strategies households deployed. METHODS Household surveys were conducted as part of ongoing monitoring programs during the latter half of 2020. Sites in seven countries were covered: Burundi; Kenya; Rwanda; Tanzania; Uganda; and then Vietnam and Zambia. Findings are representative of smallholder farmers across multiple districts per country. RESULTS AND CONCLUSIONS Our results show that the effects of the COVID-19 containment measures were widespread and often perceived to be severe. Food purchase, off farm income, sale of farm produce, and access to crop inputs were all affected. In locations under more stringent restrictions during the time of the survey, up to 80% of households had to reduce food consumption or variety. Almost all households with off-farm incomes reported reductions, by half on average. A half to three-quarters of households (depending on the location) with income from farm sales reported losses compared to the pre-pandemic situation. In locations with more relaxed containment measures in place during the time of the survey, less frequent and less severe economic and food security outcomes were perceived by the respondent, with around 20% of households reporting negative outcomes. Mobility restrictions, reduced market access, crashes in sale price for agricultural goods, and soaring prices for food purchase were key factors. Sale prices generally dropped for all agricultural products in any given location, and affected not only high value perishable products, but also staple crops such as maize and cassava. Depending on the location, between 30% and 90% of the households applied coping strategies in response to the pandemic during 2020. There was an almost complete absence of official aid amongst households interviewed. SIGNIFICANCE Our results raise the thorny issue of how best to balance containment of COVID-19 against the wellbeing of the vulnerable rural population in lower- and middle-income countries. There is a risk that the buffering capacity of rural people will become exhausted. Possible policy measures to limit negative outcomes include i) tiered mobility restrictions with travel allowed for economic reasons; ii) short-term price guarantee schemes to stabilise the food system; iii) direct aid; iv) the timely re-installation of distribution channels for agricultural inputs.

Studies that quantify nitrous oxide (NO) fluxes from African tropical forests and adjacent managed land uses are scarce. The expansion of smallholder agriculture and commercial agriculture into the Mau forest, the largest montane forest in Kenya, has caused large-scale land use change over the last decades. We measured annual soil NO fluxes between August 2015 and July 2016 from natural forests and compared them to the NO fluxes from land either managed by smallholder farmers for grazing and tea production, or commercial tea and eucalyptus plantations (n=18). Air samples from 5 pooled static chambers were collected between 8:00am and 11:30am and used within each plot to calculate the gas flux rates. Annual soil NO fluxes ranged between 0.2 and 2.9kgNhayr at smallholder sites and 0.6-1.7kgNhayr at the commercial agriculture sites, with no difference between land uses (p=0.98 and p=0.18, respectively). There was marked variation within land uses and, in particular, within those managed by smallholder farmers where management was also highly variable. Plots receiving fertilizer applications and those with high densities of livestock showed the highest NO fluxes (1.6±0.3kgNO-Nhayr, n=7) followed by natural forests (1.1±0.1kgNO-Nhayr, n=6); although these were not significantly different (p=0.19). Significantly lower fluxes (0.5±0.1kgNhayr, p<0.01, n=5) were found on plots that received little or no inputs. Daily soil NO flux rates were not correlated with concurrent measurements of water filled pore space (WFPS), soil temperature or inorganic nitrogen (IN) concentrations. However, IN intensity, a measure of exposure of soil microbes (in both time and magnitude) to IN concentrations was strongly correlated with annual soil NO fluxes.

No abstract

Coffee is a primary cash crop and banana a primary food crop in the East African highlands region, including Rwanda, Burundi, north-west Tanzania, west and central Kenya and eastern Democratic Republic of Congo. These two crops often occur on the same smallholder farms, either planted on separate plots or intercropped. In certain countries, intercropping coffee and banana is voluntarily practised, while in others governments recommend growing these crops on separate plots. Even if intercropping coffee and banana leads to a decrease in coffee yields under certain conditions, it gives certain advantages to smallholder farmers. Intercropping offers higher returns per unit of land compared with coffee alone. Farmers increasingly resort to intercropping as a result of declining farm sizes, and in an effort to reduce risks related to income and food security. Researchers have identified the potential opportunity for intercropping coffee and banana for smallholder farmers, but many public and private development partners have not yet fully embraced this technology. The benefits and constraints of intercropping coffee and banana are discussed based on results from Burundi, Rwanda and Uganda. The aim is to understand the drivers of this system in Uganda, where intercropping is a common practice, so that a framework can be suggested to develop research and recommendations for intercropping coffee and bananas in Burundi and Rwanda, where intercropping is under experimentation and has high potential.

This study aims to explain effects of soil textural class, topography, land use, and land use history on soil greenhouse gas (GHG) fluxes in the Lake Victoria region. We measured GHG fluxes from intact soil cores collected in Rakai, Uganda, an area characterized by low‐input smallholder (<2 ha) farming systems, typical for the East African highlands. The soil cores were air dried and rewetted to water holding capacities (WHCs) of 30, 55, and 80%. Soil CO2, CH4, and N2O fluxes were measured for 48 h following rewetting. Cumulative N2O fluxes were highest from soils under perennial crops and the lowest from soils under annual crops (P < 0.001 for all WHC). At WHC of 55% or 80%, the sandy clay loam soils had lower N2O fluxes than the clay soils (P < 0.001 and P = 0.041, respectively). Cumulative soil CO2 fluxes were highest from eucalyptus plantations and lowest from annual crops across multiple WHC (P = 0.014 at 30% WHC and P < 0.001 at both 55 and 80% WHC). Methane fluxes were below detectable limits, a shortcoming for using soil cores from the top soil. This study reveals that land use and soil type have strong effects on GHG fluxes from agricultural land in the study area. Field monitoring of fluxes is needed to confirm whether these findings are consistent with what happens in situ.

Crop-livestock farms across Africa are highly variable due to in agroecological and socioeconomic factors, the latter shaping the demand and supply of livestock products. Crop-livestock farms in Africa in the 20-first century are very different from most mixed farms elsewhere in the world. African crop-livestock farms are smaller in size, have fewer livestock, lower productivity and less dependency on imported feed than farms in most countries of Europe, the Americas and the intensive agricultural systems of Asia. This paper discusses the role African crop-livestock farms have in the broader socio-agricultural economy, and how these are likely to change adapting to pressures brought on by the intensification of food systems. This intensification implies increasing land productivity (more food per hectare), often leading to more livestock heads per farm, producing fertilized feeds in croplands and importing feed supplements from the market. This discussion includes (1) the links between crop yields, soil fertility and crop-livestock integration, (2) the increasing demand for livestock products and the land resources required to meet to this demand, and (3) the opportunities to integrate broader societal goals into the development of crop-livestock farms. There is ample room for development of crop-livestock farms in Africa, and keeping integration as part of the development will help prevent many of the mistakes and environmental problems related to the intensification of livestock production observed elsewhere in the world. This development can integrate biodiversity, climate change adaptation and mitigation to the current goals of increasing productivity and food security. The inclusion of broader goals could help farmers access the level of finance required to implement changes.