The effect of intercropping crop type on soil fertility, olive trees productivity and quality in Moroccan agroforestry systems

Soil degradation has continued to increase in recent decades, affecting their productivity and jeopardizing food security as a result. Agroforestry is among the recommended practices to restore soil fertility. In Morocco, this practice is generally based on the olive tree and annual crops. Furthermore, the olive tree occupies an important and exceptional place in the national agricultural strategy. However, the olive yields remain below the potentialities of the sector. Therefore, this work aimed to investigate the effects of different intercropping systems: olive-chickpea, olive-faba bean, olive-lentil, and olive-soft wheat, on cv. Haouzia olive tree productivity and quality in the Saiss region of Morocco. Indeed, soil samples (0–30 cm) and olive leaves were taken during 4 stages of olive cultivation to monitor soil fertility and the nutritional status of the olive tree in the four intercropping systems studied as well as in monoculture. The results showed that all intercropping crops did not decrease the olive tree yield compared to the olive tree in monoculture. However, olive leaf potassium levels were higher for olive trees without intercropping in the olive fruit growth stage. Soil organic matter content significantly improved for olive-chickpea and olive-lentil treatments compared to monoculture and to the other intercropping. The findings suggested that using agroforestry intercropping systems can be an effective practice for the sustainable production of olive orchards. Legumes, especially chickpeas, could present good crops to associate with the olive tree. It could optimize olive trees productivity, preserve soil fertility, and ensure more returns to farmers.