Application of arbuscular mycorrhizal fungi alone or combined with different composts to improve physiological and biochemical attributes related to drought stress tolerance in quinoa

PurposeCurrently, the problem of increasing water stress is growingly perceived as a worldwide systemic risk. Effective and sustainable use of biostimulants/biofertilizers based on arbuscular mycorrhizal fungi (AMF) and compost would be necessary to minimize losses and maintain crop productivity in arid and semi-arid areas. In this study, we evaluated the performance of the AMF consortium (Mc) in combination with composts [green waste 5% (GW5) and 10% (GW10)] and horse manure [(HM5) and (HM10)] compared to the pure strain (Ms) applied separately and/or in combination with the same biofertilizers.MethodsTwo groups of quinoa plants were installed: 1) plants grown under well-watered [WW: 75% field capacity (FC)] and 2) plants cultivated under water stress (WS: 25% FC) during four months. At harvest, mycorrhization parameters, growth, physiological, biochemical, and soil characteristics were evaluated.ResultsThe McHM10-application increased the stomatal conductance and seeds' yield by 20% and 277%, respectively, compared to the control under WS. However, GW10 showed an improvement of chlorophyll a and b by 132% and 206%, respectively, compared to the control under WS. McGW10-plants recorded an increase in sugar contents by 139% in seeds compared to the control-plants under WS. Moreover, the AMF application alone or combined with GW5 or HM5 improved the peroxidase and polyphenol oxidase activity in the leaves and seeds of quinoa. Furthermore, the GW10 or HM10 enhanced the carbon and total organic matter compared to the control soil.ConclusionsOverall, the results indicate that the application of AMF, more specifically Mc, in combination with composts can boost a better tolerance of the quinoa crop by improving the physiological and biochemical traits against oxidative damage during the drought stress period.