To meet food demand after the failure of irrigation system developments, agricultural intensification is occurring in inland valley agro-ecosystems in sub-Saharan Africa. Agricultural enhancement in inland valleys, which undermines environmental sustainability, was assessed using 'Driving Force-Pressure-State-Impact-Response' approach in four agro-ecological zones of Benin. The survey revealed that inland valleys are largely devoid of ligneous species. Crop residues are mainly transferred from inland valley fields to feed cattle, burnt in situ by the farmers themselves or abandoned to wildfires or to pasture-not mulched. Crop diversification is not universal and is limited to rice and vegetables crops. Monocropping of rice, practised by 83.3% of inland valley farmers, requires large chemical fertilizer application despite their impacts on environment including land degradation and water contamination. A major challenge is to determine means of characterizing entire agro-ecosystems of inland valleys in a way that is simple enough to be effectively and efficiently monitored. Inland valley agricultural development projects might include backstopping activities and policies that enable monitoring of chemical inputs and farming practices in inland valleys to reduce negative impacts on the environment and human health.

The Agro-Ecological Zone of the Center of Benin is facing a growing degradation of agricultural land with multiple consequences at social and economic levels. This study aims to estimate the economic value of this degradation. The experimental set up is a Fisher block with corn as vegetative material. This is an arrangement of separate blocks of one factor and two levels. The first level is without fertilizer and the second with mineral fertilizer as the dose recommended by the Agricultural Management Services. Each block is a repetition and each repetition is performed by a producer on his farm. Thus, there were a total of 12 producers at a rate of 4 for highly degraded lands, 4 for those moderately degraded and 4 for low degraded lands. The evaluated agronomic parameters are related to the growth in height and circumference of the plants' girth and the corn yield. The test shows on one hand, a drop in yield of about 50.85%, which is a monetary loss of 190,965 CFA per hectare for moderately degraded lands and about 84.41% for a

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Les pays de l'Afrique subsaharienne sont fortement affectés par les affres des changements climatiques. La présente étude vise à analyser les perceptions paysannes sur la variabilité pluviométrique, les mesures adaptatives dans le moyen Bénin. Des informations ethno-climatiques collectées aux moyens d'une enquête par questionnaire sur un échantillon de 270 acteurs, ont permis d'apprécier les stratégies et les mesures d'adaptation mises en oeuvre par les paysans. Le calcul de l'indice pluviométrique et la détermination des séquences sèches et humides sur la série pluviométrique de 1941 à 2010, ont permis de mieux étudier la variabilité pluviométrique. Les résultats des analyses ont montré que les principales mutations pluviométriques observées selon les perceptions paysannes sont le démarrage tardif, l'arrêt précoce et l'irrégularité des pluies (respectivement 96, 94 et 83% de réponses positives). Les conséquences se traduisent par la baisse de la productivité et du rendement agricole, le bouleversement et la non maîtrise du calendrier agricole. Les stratégies d'adaptation sont principalement l'extension des espaces agricoles, la reconversion socioprofessionnelle vers des secteurs d'exploitation forestière comme la production et la commercialisation du bois et du charbon de bois, contribuant ainsi à la régression de la couverture végétale de la région. Des mesures d'accompagnement (formation, encadrement, financement) méritent d'être prises pour identifier et vulgariser les mesures d'adaptation durables aux changements climatiques au Centre du Bénin.

The aim of the research is to assess the level of soil contamination by pesticides in Djidja's cotton area in Benin. Soil samples have been collected in nine (09) cotton fields from 15 th to 19 th March, 2014. The analysis has been done by gas chromatography after extraction and purification. The results show a soil contamination by glyphosate varying from 0.271 to 0.317 μg/kg, by profenofos varying from 0.109 to 0.130 μg/kg, by acetamiprid varying from 0.088 to 0.153 μg/kg and by cypermethrin varying from 0.165 to 0.190 μg/kg. A regular surpervision program must be planned to limit as possible the soil contamination by pesticides in this township.