We carried out mesocosm experiments using either the anecic earthworm Lumbricus terrestris or the endogeic earthworm Allolobophora chlorotica and loam, silt loam and sandy loam soils to investigate the differing impact of these earthworm of different ecotypes on aggregate formation (percentage water stable aggregates, %WSA) and soil water holding capacity (WHC), two soil properties that underpin many of the ecosystem services provided by soils. Earthworms significantly increased %WSA (by 16-56% and 19-63% relative to earthworm-free controls for L. terrestris and A. chlorotica, respectively). For L. terrestris, this increase was significantly greater in the upper 6.5 cm of the soil where their casts were more obviously present. Allobophora chlorotica treatments significantly increased WHC by 7-16%. L. terrestris only caused a significant increase in WHC (of 11%) in the upper 6.5 cm of the sandy loam soil. Linear regression indicated a consistent relationship between increases in %WSA and WHC for both earthworm species. However, for a given %WSA, WHC was higher for A. chlorotica than L. terrestris likely due to the known differences in their burrow structure. Overall, earthworms increased soil %WSA and WHC but the significant species/ecotype differences need to be considered in discussions of the beneficial impacts of earthworms to soil properties.

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This is a repository copy of Effect of earthworms on soil physico-hydraulic and chemical properties, herbage production, and wheat growth on arable land converted to ley.

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Erosion affects large parts of Moroccan land, particularly in the mountains leading to soil quality deterioration and less vegetation cover. Located in the South-west of Morocco, the Site of Biological and Ecological Interest (SBEI) of Ain Asmama, where erosion threatens a major part of the region was investigated. The site has a terraced transitional bioclimate, between arid to sub-humid, of local conservation importance. The varied, dense, continuous, and well-preserved vegetation of the area is crucial to protect the soils against erosion. Qualitative observations show that soils are increasingly degraded, water erosion is developing, and sediments accumulate in dams and ponds. In this study we have used the Revised Universal Soil Loss Equation (RUSLE) to assess the erosion risk in this area. It helped to develop a synthetic map of erosion susceptibility. Our results show that the integration of the different parameters in the water erosion process estimated the loss of soil amounting 339,03 tons/ha/year over the whole site. This is equivalent to a value of soil lowering of 2,82 cm which is considered extremely high.

North Africa (NA) is supposed to lower emissions in its agriculture to honor climate action commitments and to impulse sustainable development across Africa. Agriculture in North Africa has many assets and challenges that make it fit to use the tools of Climate-Smart Agriculture (CSA) for mitigation purposes. This study represents a first attempt to understand if CSA practices are sufficiently established in NA to contribute to reducing agriculture emissions. A PRISMA-inspired systematic review was carried out on an initial 147 studies retrieved from Scopus, Google Scholar, and the Web of Science databases, as well as from gray literature. 11 studies were included in the final analysis since they report the mitigation and co-benefits of CSA-based practices within NA. A bias risk was identified around the optimal inclusion of studies produced in French, and a specific plan was set for its minimization. Synthesis results revealed that most studies focused either on improving soil quality (nine studies) or managing enteric fermentation (two studies). The review revealed a poor establishment of the CSA framework in the region, especially in sequestering GHG emissions. A set of recommendations has been formulated to address the identified gaps from research orientations and organizational perspectives and empower the CSA as an ally for mitigation in north African agriculture.

<p>Drought is a serious natural hazard with far-reaching impacts including modification of biodiversity and other ecosystem functions, economic disruption, and a threat to human livelihoods and health through food systems alteration. Climate models project robust increases in drought and dryness in the Mediterranean region because of changing climate conditions.  Despite the scarcity of water, irrigated agriculture plays a major socio-economic role in groundwater-dependent irrigated regions of Morocco. Strategic sectors such as citrus rely on irrigation to maintain or even increase production and citrus stakeholders put sustainable irrigation management at the top priorities. This study aims to assess seasonal drought severity in the Souss plain, the largest citrus’ growing area in Morocco, using VCI (Vegetation Condition Index), TCI (Temperature Condition Index), and VHI (Vegetation Health Index) based on Sentinel-2 and Landsat 8 data. We explored the benefits of using the Soil Water Atmosphere Plant (SWAP) agro-hydrological model to optimize irrigation water management of a citrus orchard. The SWAP model was applied over three growing seasons from 2016 to 2019 to optimize seasonal water supply based on different criteria (e.g., critical soil pressure head and allowable daily stress), particularly during the drought episodes. The VHI was estimated and classified into five classes: extreme, severe, moderate, mild, and no drought. Key outputs of the SWAP model show that the farmers’ irrigation practices did not compensate for the lack of rainfall in the spring, which led to long-term unavailable water during crop development. The SWAP predictive model determined the optimal amount of water and irrigation scheduling systems to make efficient use of while maintaining appropriate yields. The developed algorithm simulation uses the minimal sufficient seasonal amount of water. The designed approach helps prevent critical stress in citrus orchards together with sustainable water distribution in accordance with best agronomic practices.</p><p><strong>Keywords</strong>: Citrus, drought, water scarcity, sustainable irrigation management, VHI, VCI, TCI, SWAP, Souss plain</p>