Oxygation : enhanced root function, yields and water use efficiencies through aerated subsurface drip irrigation, with a focus on cotton

Soil aeration is one of the critical determinants of plant production. This research investigated the potential of oxygation, the aeration of subsurface drip irrigation (SDI), to alleviate the consequences of episodic flooding associated with SDI in vertisols (the predominant soil type in cotton production) with a view to achieve improved yields and water use efficiencies. Cotton performance, as affected by aeration and irrigation application rate, was evaluated over two consecutive seasons, with a particular focus on root characteristics and physiological processes. Aerated cotton (2005 results) significantly outperformed non-aerated cotton in terms of both yield (27% more lint) and crop water use efficiency (26% more lint per megalitre water used). The more extensive root development of aerated plants suggests that the temporal hypoxic/anoxic events associated with SDI in clay soils is indeed mitigated by aeration of the irrigation water. Data from the 2006 experiment (recently harvested) are not included in this paper.