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Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.

The purpose of this study is to clarify the linkages between irrigation and poverty by offering an objective review of recent research on the subject. The key questions addressed herein are: (1) what is the role of irrigation development and management in poverty alleviation? (2) what are the linkages and pathways through which irrigation contributes to poverty alleviation? (3) what is the magnitude of anti-poverty impacts of irrigation? and (4) what are key determinants of anti-poverty impacts of irrigation? Our review focuses on topical empirical research studies in Asia.The extensive review suggests that there are strong linkages between irrigation and poverty. These linkages are both direct and indirect. Direct linkages operate via localized and household-level effects, and indirect linkages operate via aggregate or subnational and national level impacts. Irrigation benefits the poor though higher production, higher yields, lower risk of crop failure, and higher and year-round farm and nonfarm employment. Irrigation enables smallholders to adopt more diversified cropping patterns, and to switch from low-value subsistence production to high-value market-oriented production. Increased production makes food available and affordable for the poor.The indirect linkages operate via regional, national, and economy-wide effects. Irrigation investments act as production and supply shifters, and have a strong positive effect on growth, benefiting the poor in the long run. Further, irrigation benefits also accrue to the poor and landless in the long run, although in the short run relative benefits to the landless and land-poor may be small, as the allocation of water often tends to be land-based. Despite that, the poor and landless benefit, in both absolute and relative terms, from irrigation investments. Recent advances in irrigation technologies, such as micro-irrigation systems, have strong anti-poverty potential.Ongoing studies in Asian countries document strong evidence that irrigation helps to alleviate both permanent and temporary poverty. Further, it helps to alleviate poverty in its worst forms, namely chronic poverty. In general, irrigation is productivity enhancing, growth promoting, and poverty reducing. Instances of negative externality effects associated with large and medium-scale irrigation systems point to management issues, and therefore call for more comprehensive response mechanisms from the planning and the political community alike. The antipoverty impacts of irrigation can be intensified by creating conditions or enabling environments that could achieve functional inclusion of the poor. These include: (1) equitable access to land; (2) integrated water resource management; (3) access to and adequacy of good quality surface and groundwater; (4) modern production technology, (5) shift to high-value market-oriented production; and (6) opportunities for the sale of farm outputs at low transaction costs.

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