Most of rangeland soils are limited in their ability to supply adequate nutrients to plants. Soil conditioners have been shown to alter soil fertility and plant characteristics. This investigation aimed to evaluate the influence of two soil conditioner on nutrition value of N. schoberi and A. podolobus. For this, two separate experiments for each species were carried out in greenhouse using completely randomized design with three replications during 2018 and 2019. Treatments were four levels of wheat straw Biochar (WSB), as well as, lignite at rates of 0, 1.25%. 2.5% and 3.75% w/w added to clay loam soil. In the end of vegetative stage and before flowering, plant samples were taken and their Crude protein (CP) and Acid detergent fiber (ADF) content were measured and then Dry matter digestibility (DMD) and Metabolizable energy (ME) were calculated. Data were analyzed by One-way analysis of variance (ANOVA) and the means were compared using Duncan's test. The results demonstrated that WSB addition had no effect on nutrition value of both species. By application of Lignite, CP content of N. schoberi enhanced up to 44.45%, than that for control. The effect of lignite addition on nutrition value traits was high for N. schoberi. But this material had no effect on A. podolobus quality traits. Based on our findings, application of Lignite at 3.75 (w/w) recommended to improve soils of rangeland for cultivation of N. schoberi in dry-lands plantation projects or the conversion of dry lands to arable pastures. Manuscript profile