Poor soil aeration or oxygen deficiency is a major factor limiting seedling establishment. Oxygen deficiency in the soil can occur because of improper soil management, such as over- irrigation and soil compaction; poor soil quality, such as heavy fine-textured soils or layered soils with inadequate drainage; excessive rainfall or flooding; usage of excessively small containers for transplant production. Inferior stand establishment can occur due to the inhibitory effects of low aeration on root elongation, proliferation, viability, respiratory capacity, carbohydrate accumulation, hormone synthesis, and water and nutrient uptake. Plants that are tolerant to low soil aeration may develop morphological and anatomical features in roots that facilitate oxygen utilization and plant survival of low oxygen stress. These adaptive responses include the formation of aerenchyma tissues in the root cortex, development of adventitious roots near the soil surface, and increases in root diameter.