Oxygation to Unlock Yield Potential of Crops: A Review

Irrigated agriculture has played a vital role in supporting a dramatic increase in global food production over recent decades. However, only 20 per cent of the world’s agricultural land is irrigated. It produces 40 per cent of world’s food supply. Even the traditional practices of irrigation, in whatever form, will have transient of long term depressive effects of soil oxygen content. The depressive effect of irrigation on soil oxygen is higher for a given soil water potential on heavy clay soils (e.g., for vertisols) than on lighter soils Hence plants suffered from sub-optimal oxygen supply in the root zone and causes hypoxia and anoxia. Aeration of subsurface drip irrigation (SDI) has been shown to alleviate soil hypoxia/anoxia by providing air/oxygen to an oxygen-depleted plant root zone. This can be achieved by coupling an air injector venturi to draw air into the subsurface drip irrigation system is known as oxygation/aerogation/air injection. Oxygation assures optimal root function, microbial activity and mineral transformations, which lead to enhanced yield and water use efficiency under hypoxic (anaerobic) conditions. It also improves plant performance and yield under irrigated conditions (i.e. crops such as radish by 9.87 per cent and cotton lint yields by 10 per cent) previously considered to be satisfactory for crop growth and offers scope to offset some of the negative impacts of compaction and salinity related to poor soil aeration on crop growth. The aeration condition of irrigated soils deserves more attention than it has received in the past, if we wish to unlock yield potential constraints by soil oxygen limitations in irrigated areas and enhance the yield potential to meet the future food (and fibre) demand.