Alternative method for vegetables cultivation in Benin

In the developing countries populations, which are already vulnerable and food insecure, are likely to be the most seriously affected by the effects of climate change, e.g. yield decreases and price increases for the most important agricultural crops. The IPCC's Fourth Assessment Report for Africa describes a trend of warming at a rate faster than the global average and increasing aridity: in many parts of Africa, it seems that warmer climates and changes in precipitation will destabilise agricultural production and aggravates food security. The present work concerns the vegetables cultivation in the Parakou region in Benin, where agriculture employs approximately 70% of the active population and contributes to 36% of the Gross Domestic Product and 88% of export earnings. However, the agricultural sector has been regarded as unproductive with low adaptation capacities because of structural factors (e.g. high level of poverty among rural populations, weak mechanization and intensification of production modes), but also because of natural constraints (e. g. poor management of water and soils, leading to soil degradation). Considering the aridity, the low carbon content and the reduced level of nutrients available in the soil, the use of an hydroponic module has been hypothesised. In this way sufficient yields of the crops may be assured and no agricultural machines will be needed for the tillage operations. In addition, the nutrients can be added to the growing solution using residual materials as poultry manure, ashes and green wastes. In order to verify if some construction or maintenance problems can occur and if a growing solution can be easily obtained using agricultural wastes, some tests have been carried out. Moreover laboratory analyses have been done for different solutions that may be adopted with different shares of water, poultry manure, ashes and green wastes. The tests have indicated that the hydroponic module could be used in Benin without incurring in technical problems and that a growing solution containing poultry manure, ashes and green wastes can supply to the crops a significant amount of nutrients.