Curbing the Salinization of Arable Land and Agronomically Restoring Salt-affected Soils, a food security challenge: assessment and prospects, the case of Senegal, West Africa

Abstract

In Senegal, the Senegalo-Mauritanian sedimentary basin is cut by four major rivers: Senegal, Sine-Saloum, Gambia and Casamance, flowing into the Atlantic Ocean. The marine transgressions and regressions of the recent Quaternary, the weak dips and the climate pejoration predetermine invasions by Ocean waters, causing the salinization of watercourse and soils. The area of salt-affected soils is estimated at 1.7 million hectares, or nearly 45% of the arable land. This salinization, accompanied in some cases by acidification, compromises the food security of the local populations. Indeed, the loss of agricultural land through salinity in a context of constant population growth has a direct negative impact on food security. To curb the salinization of the land and recover salt-affected soils, several technologies have been implemented. However, the salinization is not declining. This work involves taking stock of these technologies and briefly assessing their impact. To do this, physico-chemical (profile description, EC, pH, SAR, ESP, exchangeable bases – Ca, Mg, K and Na, ion balance, CEC, Base Saturation Percentage, Organic Carbon, Nt, Pt and P₂O₅, C/N Ratio, etc.) and perception data were collected and processed. It appears that a lot of effort has been made and lot of experience gained through the combination of local and scientific knowledge. However, there is much to be done and four main priorities have been proposed for a global and integrated approach to address the problem of salinization and/or acidification. These include (i) updating of salt-affected soils inventory and mapping, (ii) scaling up the remediation technologies, (iii) introducing innovative technologies including bio-saline agriculture and (iv) training and research. Reversing the trend of land salinization will require strong political will and institutional arrangements based on a holistic approach.