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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.

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The aim of this study was to characterize 27 feed additives marketed as mycotoxin binders and to screen them for their in vitro zearalenone (ZEN) adsorption. Firstly, 27 mycotoxin binders, commercially available in Belgium and The Netherlands, were selected and characterized. Characterization was comprised of X-ray diffraction (XRD) profiling of the mineral content and d-spacing, determination of the cation exchange capacity (CEC) and the exchangeable base cations, acidity, mineral fraction, relative humidity (RH) and swelling volume. Secondly, an in vitro screening experiment was performed to evaluate the adsorption of a single concentration of ZEN in a ZEN:binder ratio of 1:20,000. The free concentration of ZEN was measured after 4 h of incubation with each of the 27 mycotoxin binders at a pH of 2.5, 6.5 and 8.0. A significant correlation between the free concentration of ZEN and both the d-spacing and mineral fraction of the mycotoxin binders was seen at the three pH levels. A low free concentration of ZEN was demonstrated using binders containing mixed-layered smectites and binders containing humic acids.

Arenosols cover extensive areas in coffee producing, humid tropical countries of Sub-Sahara Africa (Angola, DR Congo) and Southern America (Brazil). A laboratory experiment was undertaken to examine the potential of using coffee waste to improve the physico-chemical properties of an Arenosol from DR Congo. The amendment was applied at three rates to the topsoil and incubated in soil columns at field moisture capacity for 24 months. A control without any amendment was integral to the completely randomized experimental design involving three replicates. The soil columns were watered weekly with an amount of distilled water approximating to 87% of the average rainfall. Every 3 months, the soil chemical properties and the fraction of leached water and cations were measured. All application rates raised soil pH above 5.5 within 3 months. Exchangeable Ca, Mg and K showed respectively, 5 to 7-, 2 to 3-and 7 to 14-fold increases with increasing application rates. Organic C and total N significantly increased within 6 months to ca. 1.5 and 0.12% respectively, inducing a decrease in the C ⁄ N ratio from 17 to 13. The combined action of increasing soil pH and organic C contributed to a significant increase in cation exchange capacity. Increases in available P were significant, but temporary, with maximum values attained at 9 months. Coffee waste application significantly increased the fraction of retained soil water from 53% to 60%. It promoted the retention of basic cations, immobilized Mn, but increased the mobility of Fe. Coffee waste has the potential to be used as a liming material, an NPK fertilizer and has the benefits also of increasing water and nutrient retention.Coffee waste application to improve sandy soils 95

Baseline concentration levels of trace elements in the soils of Flanders (Belgium) were assessed as a function of clay and organic carbon contents. Outliers in the data were identified and rejected according to statistical criteria. Median trace element concentrations in mg/kg dry weight were As 7, Cd 0.18, Co 0.05, Cr 24.6, Cu 9.6, Hg 0.17, Ni 3.5, Pb 21.5, Zn 34.5. Clay and organic carbon contents were found significant in predicting soil trace element contents in unpolluted soils. The coefficients of determination ranged from 0.07 (Hg) to 0.69 (Ni). Based on confidence intervals of the observations, trace element concentrations that have a known probability of being exceeded can be assessed as a function of clay and organic carbon content and used as soil quality reference values.

Climate change is now affecting global agriculture and food production worldwide. Nonetheless the direct link between climate change and food security at the national scale is poorly understood. Here we simulated the effect of climate change on food security in China using the CERES crop models and the IPCC SRES A2 and B2 scenarios including CO2 fertilization effect. Models took into account population size, urbanization rate, cropland area, cropping intensity and technology development. Our results predict that food crop yield will increase +3-11 % under A2 scenario and +4 % under B2 scenario during 2030-2050, despite disparities among individual crops. As a consequence China will be able to achieve a production of 572 and 615 MT in 2030, then 635 and 646 MT in 2050 under A2 and B2 scenarios, respectively. In 2030 the food security index (FSI) will drop from +24 % in 2009 to −4.5 % and +10.2 % under A2 and B2 scenarios, respectively. In 2050, however, the FSI is predicted to increase to +7.1 % and +20.0 % under A2 and B2 scenarios, respectively, but this increase will be achieved only with the projected decrease of Chinese population. We conclude that 1) the proposed food security index is a simple yet powerful tool for food security analysis; (2) yield growth rate is a much better indicator of food security than yield per se; and (3) climate change only has a moderate positive effect on food security as compared to other factors such as cropland area, population growth, socio-economic pathway and technology development. Relevant policy options and research topics are suggested accordingly.