The Mechanisms Driving Ammonia Emission Variations in Alkaline Soil Under Different Irrigation and Fertilization Management Practices in Arid Regions

Abstract

The strategy to reduce agricultural ammonia (NH₃) emissions is a focus of attention for governments and scientists around the world. However, the effect of different irrigation and fertilization management practices on NH₃ emission in alkaline soil and the underlining mechanisms are poorly understood. An experiment with drip fertigation (a combination of fertilizing and irrigation), sprinkler fertigation, and traditional furrow irrigation with chemical fertilizer spraying was conducted in potato fields with alkaline soil in arid areas of Northwest China. The objective of this study was to investigate the effect of three irrigation and fertilization management practices on NH₃ emissions using the static box-venting method in a three-year in situ trial. There are significant seasonal difference for NH₃ emission fluxes in alkaline soils under different fertilization and irrigation management practices. The accumulative NH₃ emissions in the alkaline soil from drip fertigation and sprinkler fertigation was 55.93% and 54.05% lower than that from traditional furrow irrigation, respectively. The dynamic changes of NH₄⁺-N and NO₃⁻-N in alkaline soil were the most important factors controlling the differences of NH₃ emissions under different irrigation and fertilization methods. Drip fertigation significantly reduced NH₃ emission intensity in alkaline soil, and were important measures for reducing agricultural NH₃ emissions and ensuring potato yield in alkaline soil farmland in arid regions.