Success Stories

Tuskegee University Training Program

The Web-based PRDSS, developed jointly by FAO/IAEA and IFDC, has proved to be an attractive tool for farmers and land managers to determine how to decide the right choice of P fertilizers for crop productivity. PRDSS takes into account both economics and agronomic effectiveness of PR sources to crops.

In October 2007, Tuskegee University in Alabama, USA, conducted a special training program funded by USAID on soil fertility management. Fifteen scientists from the West African countries of Mali, Burkina Faso, Chad, Senegal, and Benin attended. All of the countries except Chad have significant indigenous PR deposits. Dr. S.H. (Norman) Chien, a retired IFDC Principal Soil Scientist and one of the key players in the development of the PRDSS Web-based system, was invited to speak on the agronomic use of PR and on the use of the Web-based PRDSS.

An explanation of the PRDSS was followed by a demonstration and each trainee used his or her computer to gain hands-on practice. They used the PRDSS database for their own PR sources to predict relative agronomic effectiveness under different soil and crop conditions as compared with WSP fertilizers. In their countries and in many other Sub-Saharan African countries, WSP fertilizers are imported.

The trainees indicated that they would take this new information technology back home, share with colleagues, and test the predicted RAE of PR against the actual observed RAE obtained from agronomic field trials. Then they intend to use the PRDSS to evaluate economic feasibility of the local PR sources with imported WSP. The Web-based PRDSS can thus be used as a training tool for researchers in developing countries with endowed indigenous PR deposits.

Evaluating PR Sources for Brazil

The Web-based PRDSS has helped a Brazilian fertilizer company decide whether to conduct more agronomic field trials and which PR sources to use before marketing imported PR. In 2006, the company contacted IFDC regarding its plan to import two new PR sources into the market and requested that IFDC perform feasibility studies of these and local PR sources using PRDSS. Brazilian fertilizer companies import several reactive PR sources from North Africa and the Middle East for agronomic use. The National Association of Fertilizer Diffusion (ANDA) reported that about 320,000 tons of PR was imported in 2000 for direct application.

After measuring the solubility of the PR samples sent by the company, IFDC scientists used PRDSS under different soil and crop conditions as specified by the company to estimate RAE of the given PR sources against an imported PR source in Brazil. Thus, PRDSS can be used commercially by fertilizer companies to estimate whether locally produced or foreign imported PR sources have commercial viability to compete with other PR sources or WSP fertilizers in the market.

Great Lakes Region of Central Africa

Use of local resources such as PR is always an attractive option compared to foreign imported P fertilizers, particularly in Sub-Saharan Africa. IFDC began a 5-year project in October 2006 to improve soil fertility, enhance farm production, and increase trade in the Great Lakes Region of Central Africa. The Dutch Embassy in Rwanda funds the project that includes Rwanda, Burundi, Congo (Dem. Rep.), Tanzania, and Uganda.

The soils in the lake regions are generally acid and low in soil fertility, particularly P. There is a significant PR deposit (Montongo) in Burundi. An IFDC staff with limited computer experience used the Web-based PRDSS to test the agronomic potential of Montongo PR and found that it was not suitable for direct application in acid soils due to its very low reactivity.

On the other hand, PRDSS predicted that a highly reactive Minjingu PR from Tanzania could be as effective as imported WSP fertilizers. However, the estimated price of Minjingu PR in Burundi was almost twice as expensive as imported high analysis water-soluble diammonium phosphate (DAP) on a per unit of P2O5 basis due to large transportation cost associated with Minjingu PR.

Consequently Minjingu PR cannot be recommended as a P source for agronomic use in Burundi unless other potential benefits of reactive PR outweigh the economic benefits from DAP. These benefits include (1) providing Ca nutrient, (2) reducing acidic Al toxicity, (3) decreasing soil acidification induced by N fertilizers, and (4) long-term PR residual effect.

Thus PRDSS results showed that having PR deposits locally or regionally should not mean automatic use of these PR sources because they may not be agronomically reactive (Montongo PR) or they may be more expensive (Minjingu PR) than imported WSP. On the other hand, if the emphasis is on local resource use and regional development, then efforts to reduce transportation cost of PR from mines to farmers’ fields become critical.