Can perennials plants be used to improve soil health in drought affected Mediterranean regions?

Abstract

• New perennial grains were assessed under Mediterranean conditions in Morocco. • Biofunctool® provided a cost-efficient method to assess soil health in Morocco. • One New perennial grain showed soil health comparable to undisturbed forest soil. • New perennial wheat lines achieved better yields with less fertilizer input. • New perennial grains can contribute to soil health in Mediterranean regions. With climate change, drought is expected to intensify in Mediterranean areas, calling for crop system adaptations. Cultivation of perennial grains could address these issues due to permanent cover and ability to enhance soil health while increasing resilience and reduced input requirements. Our aim was to assess the performance of new perennial grains, and their effects on soil functioning in Morocco. We conducted a two-years experiment and analysed soil health and agronomic parameters across four crop species annual durum wheat, perennial wheat species, two new perennial wheat lines, and undisturbed forest. All perennials received less fertilizer inputs than annual wheat. Soil health was evaluated using Biofunctool®, a functional assessment framework analyzing three core soil functions: structure maintenance, nutrient cycling, and carbon transformation. As expected, the forest showed the highest health scores. Scores under annual wheat were comparable. In contrast, the perennial specie had lowest scores. Cultivation of new perennial wheat lines showed contrasting values, with one line showing similar soil health than the forest soil. The systems differed by higher total NO 3 - in annual crops and forest while higher available NO 3 - were observed in perennials and annual crops. As well higher aggregate stabilities were found in forest. The highest grain yields were provided by new perennial grains with similar thousand kernel weight than those observed for annual wheat, despite no fertilisation. We conclude that under Mediterranean conditions, well selected perennial grains can ensure yields, with less external inputs while showing positive effects on soil health supporting their relevance for agroecological transitions.