The use of mycorrhiza in organically-grown crops under semi arid conditions: a review of benefits, constraints and future challenges

Agriculture is the primary supplier of food and fibre for humankind and maintaining its sustainability is important. Conventional agriculture (CA) compensates for its unsustainability with external inputs such as fertilisers and pesticides. Organic Agriculture (OA) aims at improving sustainability of the agricultural sector, based on amending soil with organic matter, crop rotation and careful integrated pest management. Mycorrhizae play a major role in the uptake of P and Zn in different crops. It leads to induced resistance against soil-borne and foliar diseases; to improved soil physical characteristics and to better drought and salt stress tolerance, all are important for successful OA in semi-arid conditions. Most of the mycorrhiza-related literature originated from temperate regions. The aims of this review are to highlight the specific potential benefits organically-grown crops can draw from mycorrhizal association under semi-arid conditions; to highlight soil management effects on mycorrhiza under these conditions; to understand the constraints to the use of mycorrhiza in OA under semi-arid conditions and to suggest ways to prevail over these constraints.