Evolution actuelle des sols de la couverture ferrallitique du secteur de Muheza (Tanzanie) : origine et consequences

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Brewing Technique of Mbege, a Banana Beer Produced in Northeastern Tanzania

Mbege is a beer made of banana (Musa spp.) and finger millet (Eleusine coracana). It is the most popular indigenous alcoholic beverage in northeastern Tanzania, and plays an important role in the economy of the region. In this study, we observed and recorded a detailed traditional technique for brewing mbege. We observed that mbege production was divided into three major steps: nyalu preparation, mso preparation, and mixing. Fermented porridge made of ripened banana, called nyalu, was used as a source of yeasts. As a source of fermentable sugars, a sweet porridge made of germinated finger millet called mso was used. In mso preparation, a brewing technique to enhance the effectiveness of saccharification was used. After the preparation, these two types of porridge were mixed. The ethanol concentration of the mixture increased when it was fermented for 6 h, and it then became mbege. It was supposed that yeasts in the nyalu converted fermentable sugars in the mso into ethanol. We found that the brewing technique used in the production of mbege in northeast Tanzania was similar to that used in southern Tanzania. We also demonstrated that the stem bark of Rauvolfia caffra, which was called msesewe and used as an additive in mbege production, accelerated the fermentation of nyalu and therefore increased the rate of ethanol production in the brewing of mbege. This result was consistent with the traditional knowledge in the field about the effect of msesewe on mbege production

Effect of land management on soil microbial N supply to crop N uptake in a dry tropical cropland in Tanzania

In Sub-Saharan Africa, conservation of available soil N during early crop growth, when N loss by leaching generally occurs, is important to improve crop productivity. In a dry tropical cropland in Tanzania, we assessed the potential role of soil microbes as a temporal N sink–source to conserve the available soil N until later crop growth, which generally requires substantial crop N uptake. We evaluated the effect of land management [i.e., no input, plant residue application before planting (P plot) with or without fertilizer application, fertilizer application alone, and non-cultivated plots] on the relationship between soil N pool [microbial biomass N (MBN) and inorganic N] and crop N uptake throughout the ∼120-d crop growth period in two consecutive years. In the P plot, MBN clearly increased (∼14.6–29.6 kg N ha[−1]) early in the crop growth period in both years because of immobilization of potentially leachable N, and it conserved a larger soil N pool (∼10.5–21.2 kg N ha[−1]) than in the control plot. Especially in one year in which N leaching was critical, increased MBN maintained a larger soil N pool in the P plot throughout the experimental period, and a delay of increased MB C:N ratio and a substantial decrease in MBN was observed, indicating better soil microbial N supply for crop N uptake during later crop growth. Therefore, plant residue application before planting should enhance the role of soil microbes as a temporal N sink–source, leading to the conservation of potentially leachable N until later phase of crop growth, especially in years in which N leaching is relatively severe. Although further studies are necessary, our results suggest that plant residue application before planting is a promising option to achieve better N synchronization

Towards a harmonisation of the soil map of Africa at the continental scale

In the context of major global environmental challenges such as food security, climate change, fresh water scarcity and biodiversity loss, the protection and the sustainable management of soil resources in Africa are of paramount importance. To raise the awareness of the general public, stakeholders, policy makers and the science community to the importance of soil in Africa, the Joint Research Centre of the European Commission has produced the Soil Atlas of Africa. To that end, a new harmonised soil map at the continental scale has been produced. The steps of the construction of the new area-class map are presented, the basic information being derived from the Harmonized World Soil Database (HWSD). We show how the original data were updated and modified according to the World Reference Base for Soil Resources classification system. The corrections concerned boundary issues, areas with no information, soil patterns, river and drainage networks, and dynamic features such as sand dunes, water bodies and coastlines. In comparison to the initial map derived from HWSD, the new map represents a correction of 13% of the soil data for the continent. The map is available for downloading

Cropland intensification mediates the radiative balance of greenhouse gas emissions and soil carbon sequestration in maize systems of sub-Saharan Africa

The depository provides data that supports the findings of the above titled manuscript. These data include field monitoring of soil-climatic factors, field measurements of greenhouse gas (CO2, CH4, and N2O) flux conducted in maize systems of east African highlands using the static chamber method, and the simulated output of cumulative SOC change under different cropland intensification practices. A list of reference is also included for the synthesis of changes in soil carbon stocks under investigated intensification practices. For details, please refer to the companion paper, which will be linked following manuscript publication. </p