Integrated Soil Fertility Management to Address Food Security and Enhance Forest Ecosystems Sustainability in “Trois Rivières” Forest Reserves (Benin, West Africa)

The “Trois Rivières” natural forest reserves is one of the largest and strongly threatened rainforest ecosystems in Benin. That is mainly caused by extensive agriculture, which is mostly practised by smallholder farmers, aggravated by yields dropping linked to climate change. This research aims at analysing ecological practices that will enable smallholder farmers to increase yields on marginal lands and avoiding extensive agriculture towards forest ecosystems conservation. So, the conservation agriculture experimentation fields, using maize as basis crop, were installed, within agroforestry series on three sites chosen according to farmer’s land use duration practices (Early fallow: after 6 years of cultivation, Under cultivation: after 3 years of cultivation and Late fallow: first year of cultivation after 6 years of fallow) according to a complete randomized block design with split plot arrangement involving two factors: soil and water conservation (SWC) technologies with three levels and type of fertilization with five levels including improved fertilization called “microdose”. Data were analysed by suitable tools and model in R software. Results revealed that the Large ploughing perpendicular to the slope (GB) favours better the development of maize (Leaf Area Index) on early fallow (low fertile lands). Look at the grain yield, the fertilization type Recommended Dose (RD), consuming two more times fertilizer than Microdose with manure (MDB), gives similar grain yields as MBD under GB. Thus, an application of microdoses combined with manure (cow dung) under the GB might be the solution to increase the yield on low fertile or marginal land and allow settling farmers and limiting extensive agriculture in “Trois Rivières” natural reserve.