Circular agriculture is an effective approach for the management of soil organic inputs that improves soil fertility and cropping system sustainability. We developed a cropping system typology and assessed effects of crop rotation, organic fertilization, and crop residue management on soil fertility properties. Farmers in Drâa-Tafilalet oases in Morocco were surveyed, and soil was sampled and analyzed. In the most common cropping systems (Type I), date palms were associated with cereals, forages, and perennial crops. Type II cropping systems referred to a monocropped date palm of only one cultivar. In Type III, date palm was associated with other crops on part of the utilized agricultural area and monocropped on the other part. In all cropping systems, mean soil organic matter (SOM) content was less than 1.5% and the SOM:clay ratio was less than 12%, which increased the soil degradation risk. Livestock was combined with crops in Type I and III cropping systems and produced 19.4 and 24.2 t of manure per farm per year, respectively. Type I and II cropping systems produced annually 0.98 and 2.1 t.ha−1 of dry palms, respectively. Recycling these organic waste products remains a promising option that could produce organic inputs and offset the current lack of manure.

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Dry leaves of date palms (DPs) are by-products of date cultivation that are often mismanaged in oasis agroecosystems. Ideally, they should be upcycled in a circular agriculture model before producing and exporting high-value products. Compost inputs enhance soil organic matter and conserve soil. This study investigated composting of four mixtures based on farming system requirements and the availability of organic resources. The DPs were used alone or combined with sheep manure and rock phosphate. We experimented with farm-scale windrow composting to improve understanding and support decision-making. The results showed that temperature increased rapidly to 70 °C at the beginning of composting in the mixtures with manure. Organic matter content decreased by 40% in all windrows during composting, which indicated organic matter mineralisation and loss of volatile solids. Composting DP with or without sheep manure for 136 days with two turnings conserved nitrogen and increased the nitrogen content of compost. Mixing DP with sheep manure and rock phosphate increased the final total phosphorus content of compost to 0.52% (dry matter basis). Our results highlight that composting DP is a feasible alternative to improve circularity in oasis agroecosystems, by increasing organic matter content and fertiliser value, thus paving the way for sustainable production of high-value products from DP.