SOIL WATERLOGGING STRESS COMPENSATED BY ROOT SYSTEM ADAPTATION IN A POT EXPERIMENT WITH SWEET CORN ZEA MAYS VAR. SACCHARATE

Abstract

Soil waterlogging due to excess moisture resulting in hypoxic soil conditions can have detrimental effect on development of many dryland plants growing in locations with temporary water logged soils. Oxygen stress in hypoxic soils can lead to decrease root water uptake and transpiration compared to well aerated soil conditions. In turn reduction of transpiration have a positive effect on soil water budget facilitating the preservation of waterlogged state of the soil. We investigate this phenomenon in a greenhouse pot experiment using sweet corn Zea mays var. saccharate as a model species. After establishment seedlings were subject to a differentiated watering regime ranging for now watering to heavy overwatering resulting in soil waterlogging and flooding. It was observed that the elongation rate of maize seedlings decreased once soil was waterlogged. However soon after soil flooding the elongation reassumed coinciding with appearance of new adventitious roots taping the water layer above flooded soils surface. It is concluded the ability of root system adaptation to change in soil water regime determines the plant species success in sites with periodically waterlogged soils. The feedback between soil aeration status and water uptake can result in swinging between waterlogged and desiccated soil conditions, providing competitive advantages to different sets of species during dry-land and wet-land phases.