Root traits and carbon input by sweet sorghum genotypes differs in two climatic conditions

Response of sweet sorghum [Sorghum bicolor (L.) Moench] root traits and carbon (C) input under two different climatic condition is not well understood. The aims of this study were to characterize and compare root biomass and root traits of several sweet sorghum genotypes at field condition and to estimate their C input to into soil. Roots and shoots were analyzed for C concentration and CO2 was calculated. Root samples were collected through monolith root sampling techniques. Root morphological characteristics like root surface area and root volume were differed between locations as well as locations × genotypes interactions. Root surface area varies from 423,800 to 887,800 m2 ha-1 in Mediterranean soil and 339,100 to 579,600 m2ha-1 for Harran soil. All sweet sorghum genotypes inputs root and shoot C as well as CO2 higher in Mediterranean than Harran soil. Root C input varies from 140 to 386 Mg ha-1 in Mediterranean soil and 112 to 224 Mg ha-1 for Harran soil. A greater diversity of root traits was found on several sweet sorghum genotypes irrespective to plant biomass C inputs into the soil. However, compared to several sweet sorghum genotypes, their lower C input to soil needs to be recognized to ensure a balanced C budget. This study concluded that several sweet sorghum genotypes can be a good source of soil C sequestration under different climatic conditions of Turkey.