Impact of Irrigation, Nitrogen Fertilization, and Spatial Management on Maize

Improving water and N use efficiency is essential to the sustainable intensification of irrigated agriculture, providing both crop production and environmental benefits. Partial root‐zone irrigation has emerged as one of the most promising forms of deficit irrigation, irrigating only one side of the root zone during an irrigation event while keeping the other side dry. By alternating partial root‐zone irrigation with N fertilization it is a possible trigger to physiologic responses in growing crops that reduce evapotranspiration as well as to curtail nitrate leaching associated with conventional irrigation. A growing body of research reveals that careful manipulation of irrigation and N fertilizer application increases maize yield, water use efficiency, and N use efficiency while decreasing soil N leaching, N2O emission, and NH3 loss. Success, however, hinges on tying management to the dynamics of soil moisture within fertilized furrows. Part of the root system in drying soil could respond to drying by sending root‐sourced signals, such as abscisic acid, to the shoots where some of stomata may be closed to reduce water loss by evapotranspiration, but with little effect on photosynthesis. Partial root‐zone irrigation could increase water use efficiency and nitrogne use efficiency, and improve fruits quality. The separation of nitrogen and water with alternating furrow irrigation could not only keep the benefit of water saving due to soil re‐watering and re‐drying, but also have an effective strength on N use and reducing N leaching. The soil moisture with fertilized furrows is co‐related to the availability and losses of nutrients, which has a major role on the benefits of separation of nitrogen and water with alternating furrow irrigation.