Consequences of irrigation and fertigation of vegetable crops with variable quality water: Israel as a case study

Water-scarcity in dry areas is driving agriculture towards increased utilization of marginal to poor quality water sources for irrigation. This includes groundwater and recycled wastewater that tend to be characterized by high levels of minerals and commonly of problematic salts. Israel has been a global leader in irrigation application efficiency, use of groundwater with relatively high concentrations of salts and recycled municipal wastewater, and recently, in the use of large-scale seawater desalination for human consumption and irrigation. Irrigation with water high in salts has been shown to be unsustainable in many dry regions, mostly due to increasing salinity of soil, subsoil, and groundwater resulting from the application and leaching of salts. We present a summary of the direct effects of salinity on crop production, of its management in vegetable crops, and of the environmental consequences of different salinity management practices. The objective of this review is to provide a fundamental understanding of the advantages and limitations of irrigating vegetable crops as a function of water quality, considering good quality surface and groundwater, saline/brackish water, treated wastewater and desalinated water. The long-term experience of irrigation of annual vegetable and other horticultural crops with diverse water qualities in Israel is reviewed. The environmental implications of irrigation as a function of water salinity, both on a national scale and using a local case study of irrigation with brackish groundwater of vegetables in Israel's Arava Valley, are discussed. Finally, possible management strategies are suggested to reduce environmental consequences of irrigation with water containing salts and address the fundamental question; can irrigated arid zone vegetable production be sustainable?