Fertilizer Consumption Trends in Sub-Saharan Africa

Crop Production/Industries, Downloads December 2008 - July 2009: 12,

Alternative Approaches for Promoting Fertilizer Use in Africa, with Emphasis on the Role of Subsidies

Crop Production/Industries, Downloads December 2008 - June 2009: 5,

DETERMINANTS OF FERTILIZER ADOPTION BY AFRICAN FARMERS: POLICY ANALYSIS FRAMEWORK, ILLUSTRATIVE EVIDENCE, AND IMPLICATIONS

Crop Production/Industries,

Improving the Measurement and Analysis of African Agricultural Productivity: Promoting Complementarities between Micro and Macro Data

Productivity Analysis,

Promoting Farm Investment for Sustainable Intensification of African Agriculture

Farm Management, Downloads July 2008-July 2009: 9,

When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

Tree frogs need to adhere to surfaces of various roughnesses in their natural habitats; these include bark, leaves and rocks. Rough surfaces can alter the effectiveness of their toe pads, due to factors such as a change of real contact area and abrasion of the pad epithelium. Here, we tested the effect of surface roughness on the attachment abilities of the tree frog Litoria caerulea. This was done by testing shear and adhesive forces on artificial surfaces with controlled roughness, both on single toe pads and whole animal scales. It was shown that frogs can stick 2–3 times better on small scale roughnesses (3–6 µm asperities), producing higher adhesive and frictional forces, but relatively poorly on the larger scale roughnesses tested (58.5–562.5 µm asperities). Our experiments suggested that, on such surfaces, the pads secrete insufficient fluid to fill the space under the pad, leaving air pockets that would significantly reduce the Laplace pressure component of capillarity. Therefore, we measured how well the adhesive toe pad would conform to spherical asperities of known sizes using interference reflection microscopy. Based on experiments where the conformation of the pad to individual asperities was examined microscopically, our calculations indicate that the pad epithelium has a low elastic modulus, making it highly deformable

Determinants of Farm Productivity in Africa: A Synthesis of Four Case Studies

Productivity Analysis, Downloads July 2008 - July 2009: 20,

Promoting Fertilizer Use in Africa: Current Issues and Empirical Evidence from Malawi, Zambia, and Kenya

It is generally agreed that increasing agricultural productivity is critical to stimulating the rate of economic growth in Africa. There are many important and often complementary determinants of agricultural productivity. In this brief and the full paper it draws from, the focus is on fertilizer and improved seed, without intending to imply that they are the only or most significant productivity determinants.fertilizer, Africa, Malawi, Zambia, Kenya, Crop Production/Industries, Food Security and Poverty, Q18,

Promoting Fertilizer Use in Africa: Current Issues and Empirical Evidence from Malawi, Zambia, and Kenya

This study was funded jointly by the Regional Strategic Agricultural Knowledge Support System (Re-SAKSS) for Southern Africa, based at International Water Management Institute, Pretoria, South Africa, and by the United States Agency for International Development's Africa Bureau. Much of the data and analysis reported in this study was carried out under the Tegemeo Agricultural Monitoring and Policy Analysis Project, funded by USAID/Kenya; the Food Security Research Project/Markets, Trade and Enabling Environment (MATEP) Program, funded by USAID/Zambia and the Swedish International Development Agency; and by the DFID and USAID offices in Lilongwe, Malawi.fertilizer, Africa, Malawi, Zambia, Kenya, Crop Production/Industries, Q18,