Mitigation options to reduce nitrogen losses to water from crop and livestock production in China

Samenvatting

Nitrogen (N) loss from agriculture threatens water quality and affects human health, especially the nitrate leaching. In China, nitrate concentrations in ground-water frequently exceed the World Health Organization (WHO) quality standard for drinking water of 50 mg L⁻¹. In this paper we explore mitigation measures for reducing N loss to water from agriculture. Firstly, we synthesis the current state of nitrate pollution through a review the published literatures. Then, we review measures to mitigate N loss to water. Finally, we present a comprehensive scenario analysis to evaluate the effect of N loss mitigation measures, following a Nitrate Vulnerable Zones (NVZs) approach, similar to that used by EU countries. A combination of balanced N fertilization, precision fertilizer application and irrigation techniques, and a decrease of direct manure discharge into watercourses can decrease N loss from the area of potential designated NVZs by nearly 50% compared to the reference year - 2012. We argue that further research and policy instruments for controlling N loss to water are essential for managing N in crop and livestock production systems in order to protect water quality for human consumption.