Roots play an essential role in resources acquisition and responses to abiotic stress, such as drought and waterlogging. Deep rooting trait is especially important for water and nutrient uptake at depth, and promising to improve crop yield in water-limited environments. In order to improve the speed of evaluation process for rooting traits, there is a demand to develop novel and simple techniques for root phenotyping. The objectives of this study was (1) to develop deep root phenotyping techniques, (2) to screen deep rooting genotypes and (3) to understand the functions of crop roots under abiotic stress. The objectives lead to three manuscripts.