The Sahel Project

The Sahel project focused on the optimization of the silicate technology (production and application of silicate-based plant substrates) in field tests, which were performed in the northern Sahel region in Senegal together with potential users of the technology.

The environmental conditions and the background chosen ensured that the optimization could be tested and realized under realistic conditions. The complex situation was determined by a multitude of interacting factors that were bound up with each other; these issues referred to ecological and sociological aspects as well as to the methods of production and applications.

While this "extraordinary" method of research entailed tremendous efforts concerning organization and also caused a considerably higher risk for the research project, it enabled participants to integrate the application of the silicate technology in a multi-faceted approach, which brought an increase of production, but also additional know-how for the participants.

The primary goals of the research project consisted, on the one hand, in increasing the yields in irrigation farming, always keeping in mind efficient use of water resources, and on the other hand, to prevent losses in yield when using saline water.

Another objectives was to combine the optimization process with approaches to the sustainable use of resources in agricultural production and at the same time take into account the economic necessities (increase in the production of vegetables), the ecological conditions (water deficiency, nutrient-poor soils), and the socio-cultural background.

The variables in the numerous field tests included the daily irrigation rate, water quality (saline and river water) fertilizer rates application methods, mixing technologies as well as varying amounts of the silicate substrate.

One of the most important results was that the main component of the plant substrate, i. e. the silicate powder increased the amount of plant-available water ("pF-value") by a factor of 8.

Soil analyses after application of the silicate plant substrate have also shown, that the substrate increases the storing capacity of nutrients such as potassium and phosphorus and also improves the cation exchange capacity (CEC), which improves the quality of the cultivated area.

In addition, it has been shown that under these conditions salt-tolerant or moderately salt-tolerant crops (vegetables) can be irrigated with salt contaminated water with an electric conductivity of 2.5 dS/m (SAR 26) without any losses in yield. This is also the case if the daily irrigation rates have to be reduced.

Plants in which the silicate plant substrate (SPS) had been applied to the root-stock and which had been irrigated with saline water, delivered the same yield as plants without SPS application and which were irrigated with river water. In contrast, plants that were not treated with SPS and were irrigated with saline water showed a significantly reduced yield compared to those from the control group (no SPS treatment, irrigation with river water).

Overall, the results have shown that the silicate technology, in cases where losses in yield on account of water deficiency, poor water quality, reduced vitality of the plants, extreme wind and dust loads etc. occur, may provide for considerably higher outputs even if the daily irrigation rates are reduced.

This means that the silicate technology offers the opportunity to compensate losses in yields. Thus, in a village characterized by extremely unfavorable environmental conditions (saline water, high wind loads and dust immission, etc.) using the silicate plant substrate brought an crease in yields of more than 100% compared to the reference group.

The field tests were also used to improve and simplify the production and application of the SPS. The silicate powder can be mixed with sand and, if necessary with mineral fertilizer and is then worked into the soil in this form. This enables users to easily produce and apply the product on site.

The results attained so far are very promising in many ways and highlight the potential forms of application in dry or arid areas, i.e. in Africa, India or the Middle East.

But there are also potential applications in Europe, Canada, the U.S.A. in areas with intensive agriculture, that are affected by water deficiency and soil degradation or areas that can only use saline water for irrigation. The need for solutions concerning these issues is particularly urgent, given the fact that the expanse of arid areas with deteriorating water quality and secondary salinization is constantly increasing.

Project management

• Prof. Dr. Hugo Hubacek, Staaatliche Versuchsanstalt - TGM, Baustoffe und Silikattechnik
• Dr. Katharina Zwiauer

Project team

• Prof. Dr. Hugo Hubacek
• Dr. Katharina Zwiauer
• Dipl.-Ing. (FH) Jean-Paul Uwiduhaye

Local project participants

• Mbakhana: Doudou Fall, Malik Fall, Demba Traoré, Moctar N‘Diaye
• Ourourbe: Amadou Gueye Ba, Amadou Ba, Raki Deh, Bodjel Ba und viele andere
• Übersetzer: Amadou Sow

Co-operation partners

• Univ.-Prof. Nicola Diallo ("), S. Sakho, Universität Dakar, Institut für Agronomie, Pflanzenphysiologie und Agrotechnologie
• Mamadou Fall, Convention des Associations Rurales de Mbane et du Waalo (CARAMW)
• Dr. Martina Gajdos, Institut für Afrikanistik der Universität Wien
• Dipl.-Ing. Hans Geisslhofer, Caritas Innsbruck
• Ao. Univ.-Prof. Mag. Dr. W. Gutjahr, Institut für Statistik und Decision Support Systems der Universität Wien
• Dipl.-Ing. (FH) Ronald Jaudas, Association Baraka
• Cheikh Mouhamadou Bamba Ndiaye, L'Association Pour le Développement et l'Emancipation des Jeunes et des Femmes (ADEJF)
• Mag. Harald Riedmann, Vienna Knowledge Net (vknn)

Staatliche Versuchsanstalt - TGM,
Baustoffe und Silikattechnik
Wexstraße 19-23, 1200 Wien
E-Mail: vasil@tgm.ac.at