Harnessing biological nitrification inhibition to reduce soil nitrogen losses – Systematic quantification of plant and soil factors to maximise field-scale benefits

Summary

Nitrogen fertilisation in cropping can be ineffective in conversion to production outputs due to nitrogen losses. These occur via nitrate leaching, ammonia volatilisation or as gaseous emissions, including as nitrous oxide, a potent greenhouse gas. Biological nitrification inhibition (BNI), the exudation of compounds through plant roots that limit conversion of ammonium into nitrate, may reduce such losses. Here we discuss and quantify the key plant and soil factors that affect BNI activity. This systematic approach provides a basis for understanding, and ultimately maximizing, field-scale benefits of BNI. To date, Brachiaria humidicola and sorghum have received most research attention, including characterisation of the BNI activity of their root exudates. Limited information is available