**13. Prospects and research needs**

Arsenic accumulation in rice is a substantial global concern [1, 4, 6]. The soil chemistry of arsenic accumulation in rice is rapidly being elucidated; however, studies have yet to develop consistent desirable outcomes with respect to irrigation technology, soil amendments, phytoremediation, and yield maintenance. Alternate wetting and drying and furrow irrigation are competing irrigation regimes, with research showing substantial reductions in arsenic accumulation. However, rice yield maintenance, implementing reliable nitrogen fertilization practices, and providing effective weed management programs remain problematic, especially when food security and traditions may be compounding realities. Water scarcity and climate change provide both opportunities and setbacks to altering irrigation methods [80].

The understanding of rice physiology and arsenic is beginning to be formulated. Das et al. [81] illustrated the importance of biochemical relationships involving ascorbate-glutathione cycle and thiol metabolism to support reducing yield suppression in arsenic impacted rice. Wu et al. [82] showed the promise of arsenicphosphate interactions involving phosphate transporter expression in rice. Thus, understanding arsenic root uptake at the cellular membrane level and its subsequent movement within the plant, combined with rice breeding and cultivar selection, remain clear avenues of research to reduce the human daily uptake of arsenic.

The prospect of reducing arsenic uptake rests with a global effort to: (i) produce cultivars that restrict arsenic uptake to root cells and exude arsenic to the rhizosphere, and (ii) alter irrigation practices to provide sufficient intervals of oxic soil environment to mitigate arsenic bioavailability. These approaches will also provide other environmental advantages, including water conservation and reduced methane emission [83].

*Soil Science - Emerging Technologies, Global Perspectives and Applications*
