Within the United Nations Framework

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

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Combating land degradation in the semi-arid rangeland of sub-Saharan Africa is essential to ensure the long-term productivity of these environments. In the Lake Baringo basin in Kenya, communities and individual farmers restored indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study quantified the benefits of rangeland rehabilitation using yearly communal enclosures' utilisation data compiled by Rehabilitation of Arid Environments (RAE) Trust over a 6-year period (2005)(2006)(2007)(2008)(2009)(2010). Results showed that communal enclosures provide a source of income through the sale of fattened livestock, harvested grass seeds, hay, honey and charcoal, among other products. Regression analysis showed an increasing total enclosure income with time. The enclosures also provide grasses for thatching, livestock feed and dry season grazing. Indirect products like milk, blood and meat are essential for household nutrition and food security. These benefits reinforce the management through incentive to maintain existing enclosures and establish new ones and therefore the increasing trend in rangeland enclosure. Increased soil and biomass carbon storage could come with other indirect environmental benefits including improvement in soil quality, land productivity for pasture production and food security, and prevention of land degradation, thus leading to economic, environmental and social benefit for the local agropastoralist communities.

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Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well

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