The application of carbon-rich substrates to agricultural soils is discussed as a strategy to improve soil properties and fertility, which can affect plant physiological traits and enhance agricultural crop yield. The aim of this study was to evaluate if shungite, carbon-rich sedimentary-volcanic rock, may improve plant ecophysiological traits under sufficient water supply as well as soil water deficit. A pot culture experiment was conducted with onion (Allium cepa L.) seedlings, using four shungite concentrations (0, 5, 10 and 20 g kg⁻¹) in an Umbric Podzols and two water regimes: well-watered and drying-wetting cycles. Soil water deficit decreased root nutrient content, depressed seedlings growth, net CO₂ assimilation rate (A_n), stomatal conductance (g_s) and the respiration rates in both darkness (R_d) and the light (R_l), but increased water use efficiency (WUE) at leaf level. Shungite application decreased the leaf necrosis under both water regimes and increased total leaf length of DW seedlings. Compared with the well-watered conditions, under drying-wetting cycle shungite stimulated the increase of the A_n rate and WUE at low measurement temperature. No significant effect of shungite was found for R_d, R_l, R_l/R_d, R_d/A_g (A_g = A_n + R_l) and R_l/A_g regardless soil water regimes. Shungite application was not so successful to eliminate the negative effects of soil water deficit on growth and physiological processes of A. cepa. The observed positive effects of shungite on the physiological traits of onion seedlings were more likely associated with the increase in the content of nutrients than with the improvement in soil water properties.

讨论了富碳基质在农业土壤中的应用，作为改善土壤特性和肥力的策略，可以影响植物的生理特性并提高农作物的产量。这项研究的目的是评估在充足的水供应和土壤缺水的情况下，富含碳的沉积火山岩-钨铁矿是否可以改善植物的生理生态特性。用洋葱（Allium cepa L.）幼苗进行盆栽试验，在Umbric Podzols中使用四种浓度（0、5、10和20 g kg ^-1的重晶石）和两种水域：充分浇水和干湿循环。土壤水分亏缺会降低根系养分含量，抑制幼苗生长，净CO ₂同化率（A _n），气孔导度（g _s）和在黑暗（R _d）和光照（R _l）下的呼吸速率，但提高了叶片水平的水分利用效率（WUE）。在两种水分条件下，施用钨铁矿均能减少叶片坏死，并增加DW幼苗的总叶片长度。与干湿条件相比，在较低的测量温度下，湿润条件下，钨矿刺激了A _n速率和WUE的增加。对于R _d，R _l，R _l / R _d，R _d，未发现钨矿的显着影响。/ A _g（A _g  =  A _n  +  R _l）和R _l / A _g而不管土壤水分状况如何。Shungite应用就没有那么成功消除土壤水分亏缺的生长和生理过程的负面影响圆葱。观察到的菱铁矿对洋葱幼苗生理特性的积极影响更可能与养分含量的增加有关，而不是与土壤水质的改善有关。