Impact of Bio-fertilizers under Supplementary Irrigation and Rain-fed Conditions on Some Physiological Responses and Forage Quality of Smooth Vetch (Vicia dasycarpa L.)

In arid and semi -arid regions, water scarcity and declining soil fertility limit the supply of livestock forage. This study evaluates the use of bio-fertilizers to adjustment water shortage stress and improved smooth vetch (Vicia dasycarpa L.) yield under water deficit stress conditions. A 2 -year experiment was performed in an agrisilviculture system of plum orchard in 2016 and 2017. In this study, the single, double and triple combined of Arbuscular mycorrhizal fungi (AMF)- Rhizophagus intraradices, Azotobacter chroococcum (Az) and Thiobacillus spp. (Th) on smooth vetch plants were evaluated under rain -fed and supplemental irrigation. The results indicated that irrigated plants had more Fe and Zn nutrients than rain -fed plants. In comparison with single inoculation, the combined use of AMF + A. chroococcum facilitated the forage dry matter digestibility, total digestible nutrient, net energy for lactation, dry matter intake and relative feed value. In irrigated, double and triple combination of AMF with A. chroococcum and/or Th. improved chlorophyll -a, chlorophyll -b, total chlorophyll, relative water content, total soluble sugar, ascorbic acid, and glutathione while lowering proline and malondialdehyde. The results show that synthesis non -enzymatic antioxidant because of the combined use of biofertilizers (AMF, Az and Th) can reduce reactive oxygen species damage and improve water deficit resistance and yield in smooth vetch rain -fed plants.