ABSTRACT
Organic matter [OM] is an essential soil component that results from the decomposition and decay of plant and animal materials. Decomposition processes are influenced by several biotic and abiotic factors. The Lebanese inland regions are characterized by low rain and elevated temperature. Soil formation and evolution occur under dry conditions and rare vegetation cover. Due to the absence or insufficiency of plant residues and frequent cultivation, the soils of the eastern mountain chain are characterized by low OM content. Given the importance granted to carbon sequestration in view of climate change and the importance of OM in soil fertility and resilience to erosion, the aim of this work is to assess the soil organic matter [SOM] levels by following an agropastoral system consisting of growing feed crops between the fruit trees as winter cover crops
A two-year study between 2009 and 2010 was conducted in Jurd Aarsal, Anti-Lebanon, to assess the biomass production from cover crop in orchards and to estimate the potential increase of SOM content in plots planted with legume species [Vicia sp., Lathyrus sp.] and barley [Hordeum vulgare]. Soil and plant samples were taken from 7 orchards ranging in altitude between 2016m and 2 236m. SOM was analyzed in composite samples before and after the experiment. Plant samples were collected throughout the season to assess the dry matter production. Result showed that the sites were supplemented with OM varying between 140 and 250 kg ha[-1]season[-1] resulting from the decomposition of plant root residues. The above-ground plants provided the orchards with 95-665.7 kg ha[-1]season[-1] of OM. It is suggested to follow the practice of winter cover leguminous fodder crop between fruit trees, in dry Lebanese regions, in order to provide additional biomass for small ruminants, enrich the soils with OM and fixed nitrogen and better use of surface soil moisture
ABSTRACT
The target of studying biodiversity in the south bank of Nahr-Ibrahim valley was to study models for the rehabilitation of degraded areas, with an emphasis on the diversity of wild legumes. In an altitudinal transect, the rock substrate was limestone mostly, with a few sites on basalt. Habitats were found to be mostly oak dominated open forests. All sites on limestone were highly diverse, with Shannon index reaching 3.691. The high level of heterogeneity characterizes the relatively undisturbed sites of native vegetation. Vegetation on basalt was less diverse than on limestone. Thirty species of legumes belonging to 15 genera were identified, 23 species were annual and 7 perennial. Most dominant legume species were herbaceous, except for Calicotome villosa an abundant shrub. Legumes diversity was positively linked to the number of species, the Shannon index and the coverage by the herbaceous layer. A significant association was found between Tamus, Hordeum, Dactylocteneum, Trifolium spp, Calicotome villosa, Styrax officinalis and Quercus calliprinos. This could serve as a model for future combination of potentially useful plant species