Africa’s lands are largely vulnerable and threatened by soil degradation and low water availability, especially in semi-arid and arid regions, limiting crop and livestock productivity and farmer livelihood options. Therefore, in African agricultural lands, adopting/improving measures that conserve soil and water resources is crucial. This review aims to provide an update on soil and water conservation (SWC) in terms of farmer practices and research actions and explore how SWC technologies and practices represent a pathway to build or re-establish soil health and enhance sustainable agriculture in Africa. It also aims to increase knowledge on best-fit SWC approaches. Soil conservation, which includes measures of controlling soil erosion and maintaining or improving soil fertility, is inseparable from water conservation. On agricultural lands, the two are typically co-addressed. Increasing plant biomass production through improved water, crop and soil management practices, and managing this biomass judiciously, have direct and indirect impacts on conserving soils and water resources, particularly in drylands. This study focuses on rainfed agricultural systems. We discuss the barriers and challenges to scaling up best-bet SWC technological and management options. Moreover, we show that options, such as Conservation Agriculture (CA), Agroforestry (AF), as well as integrated soil fertility management (ISFM) and field-scale rainwater harvesting (RWH), remain promising for the preservation and improvement of soil health in Africa’s farmlands and improving the resilience of agrosystems to climate change and variability as well as droughts.

Salinity is one of the most critical challenges for crop production and soil and water management in arid and semi-arid regions, such as a large area of Morocco. These regions are characterized by low rainfall with an erratic distribution, long drought periods, and high evaporation, resulting in salt accumulation in the superficial layer of the soil and soil and water degradation. Therefore, phosphogypsum (PG) could be a promising amendment to reduce the salinity effect and improve soil quality in salt-affected soils. In this context, the present study aimed to evaluate the effect of PG on the physical properties of Luvisols and Cambisols collected from salt-affected soils in four regions in Morocco: Chichaoua, Ras El Ain, Sidi Zouine, and Sed El Masjoune. The treatments consisted of different rates of PG (15, 30, and 45 t/ha), natural Gypsum (G) (15 t/ha), and control. Our findings revealed that PG application improved soil structure by promoting flocculant action provided by calcium. Linear regression indicated that Water Aggregate Stability (WAS) and PG doses were strongly correlated with a high coefficient of determination (R2 = 93.41%, p value < 0.05). Compared to the control, the overall efficiency of 45 t/ha of PG amendment reached 53%, 95%, and 36%, respectively, in Chichaoua, Ras El Ain, and Sed El Masjoune soils. PG application presented a positive effect on other soil physical properties (soil hydraulic properties, total porosity, and bulk density), especially for the soils of Chichaoua and Ras El Ain regions. The total porosity was increased by 8% with 45 t PG/ha in Ras El Ain soil, and in Chichaoua soil, the bulk density was 5% lower in the pot treated with 45 t PG/ha compared to the control. This study supports the use of PG as an amendment for reclaiming salt-affected soils through monitoring agronomic and environmental impacts.

The permanent monitoring of vegetation cover is important to guarantee a sustainable management of agricultural activities, with a relevant role in the reduction of water erosion. This monitoring can be carried out through different indicators such as vegetation cover indices. In this study, the vegetation cover index was obtained using uncalibrated RGB images generated from a digital photographic camera on an unmanned aerial vehicle (UAV). In addition, a comparative study with 11 vegetation indices was carried out. The vegetation indices CIVE and EXG presented a better performance and the index WI presented the worst performance in the vegetation classification during the cycles of jack bean and millet, according to the overall accuracy and Kappa coefficient. Vegetation indices were effective tools in obtaining soil cover index when compared to the standard Stocking method, except for the index WI. Architecture and cycle of millet and jack bean influenced the behavior of the studied vegetation indices. Vegetation indices generated from RGB images obtained by UAV were more practical and efficient, allowing a more frequent monitoring and in a wider area during the crop cycle.