Subirrigation with brackish water for vegetable production in arid regions

Brackish water is the principal source of irrigation water in many arid regions. Surface irrigation with brackish waters is limited to salt tolerant crops or is used alternately with scarce freshwater resources. However, subirrigation may help overcome some of the limitations associated with the use of brackish water in arid agricultural regions. Use of this technique to produce potatoes (Solanum tuberosum? L.), one of the world's major food crops, is investigated in this study. The yield and tuber grade of 'Atlantic' and 'Russet Burbank' potatoes were evaluated in field lysimeters packed with a sandy soil, salinized to 3.5 dS/m, and then subirrigated with water having salinity levels (ECi) of 1, 5 or 9 dS/m, beginning 13 days after planting. Preventing rainwater entry by using plastic mulch simulated arid conditions. Water tables were maintained at 40 or 80 cm below the soil surface. At harvest, soil solution salinity (ECw) in the lysimeters ranged from 3.5 to 7.6 dS/m. Water table depths or subirrigation water salinity levels had no significant effect on the total tuber weight of either cultivar. However, yield of grade A Russet Burbank tubers was greater when the water table was maintained at 40 cm. This trend was similar but not significant for Atlantic tubers. Productivity of Atlantic was lower than that of Russet Burbank. Subirrigation with brackish water in the saline soil resulted in yield that was 59% above the global average, thus demonstrating its utility for agriculture in dry regions. (C) 1999 Elsevier Science Ltd. All rights reserved.