Abstract:

Relatively high levels of boron (B) can be found in soils and irrigation water used for agriculture in semi-arid and arid regions. Furthermore, climatic conditions and resulting high levels of plant transpiration in dry regions intensify B uptake and accumulation in plants and increase the probability of B toxicity. The focus of this review is on B interactions with soils and plants in dry regions. A basic introduction to B in soils and solutions and to B in the soil-water-plant continuum is presented to provide the reader with sufficient background to understand issues of B in arid and semi-arid agriculture. Crops in arid areas are prone to exposure to stress-causing factors from excess B that occurs simultaneously with general salinity stress. In some cases in arid zone agriculture excess B is a result of native soil-born B, in other cases it is a result of B introduced with irrigation water. Both native and introduced B can have long-term consequences on crop growth and agricultural management. The nature of excess B-salinity interactions is also reviewed. Case studies representing two scenarios regarding excess B in arid agriculture are presented. In the first, naturally occurring B in vineyards in the Jordan Valley led to toxicity, even after years of leaching and irrigation with low-B water. In the second, saline water with high B concentration historically utilized in the western Negev for irrigation of cotton had serious repercussions on subsequent peanut crops. Crop and water management options appropriate to anticipated conditions of high B in arid agriculture are presented and discussed. 

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