No abstract

Knowledge of greenhouse gas (GHG) fluxes in soils is a prerequisite to constrain national, continental, and global GHG budgets. However, data characterizing fluxes from agricultural soils of Africa are markedly limited. We measured carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) fluxes at 10 farmer‐managed sites of six crop types for 1 year in Kenya and Tanzania using static chambers and gas chromatography. Cumulative emissions ranged between 3.5–15.9 Mg CO2‐C ha−1 yr−1, 0.4–3.9 kg N2O‐N ha−1 yr−1, and −1.2–10.1 kg CH4‐C ha−1 yr−1, depending on crop type, environmental conditions, and management. Manure inputs increased CO2 (p = 0.03), but not N2O or CH4, emissions. Soil cultivation had no discernable effect on emissions of any of the three gases. Fluxes of CO2 and N2O were 54–208% greater (p < 0.05) during the wet versus the dry seasons for some, but not all, crop types. The heterogeneity and seasonality of fluxes suggest that the available data describing soil fluxes in Africa, based on measurements of limited duration of only a few crop types and agroecological zones, are inadequate to use as a basis for estimating the impact of agricultural soils on GHG budgets. A targeted effort to understand the magnitude and mechanisms underlying African agricultural soil fluxes is necessary to accurately estimate the influence of this source on the global climate system and for determining mitigation strategies.

No abstract

Community based forest management (CBFM) has been implemented in Africa since the 1980s. Three main objectives, which are currently part of the sustainable development goals (SDGs), underlie the formation of CBFM. They are (1) enhancing community engagement in forest management, (2) reducing rural poverty, and (3) promoting forest resources conservation. We examine CBFM frameworks in sub-Saharan Africa (SSA) and CBFM schemes' contribution to selected sustainable development goals relevant to the forestry sector. Five SSA countries, Ethiopia, Kenya, Cameroon, Uganda, and Tanzania were chosen for the study because of their long-term engagement in CBFM. The analysis was based on desk review of literature from Web of Science!, Scopus, and Google Scholar!, and interviews with individuals representing institutions leading CBFM implementation in the countries selected. We found countries were strong in devising policy and legal provisions and articulating formalities for establishing CBFM. Major weaknesses were observed in monitoring CBFM performance, benefit sharing, and product management. The analysis of CBFM schemes' contribution to SDGs was largely positive, though with several cases of no considerable impact and few reports of negative impacts. The contributions of CBFM schemes to SDGs was constrained by weaknesses in the CBFM frameworks. Enhancing CBFM schemes contribution to SDGs requires addressing the major weaknesses observed in the CBFM frameworks.

Soil micronutrients are important elements for plant growth despite being required in small quantities. Deficiency of micronutrients can result in severe crop failure while excess levels can lead to health hazards; therefore, investigating their status in agricultural land is crucial. The correlated micronutrients implied that they were affected by similar factors. Soil pH correlated positively with B, Fe, and Mn and negatively with Cu and Zn, hence probably influencing their availability. Therefore, the need for sustaining micronutrient at sufficient levels is crucial. Management interventions may include moderating soil pH by reducing acidity through liming in the higher elevations and incorporation of organic matter in the lowlands.