GROWTH OF FABA BEAN IRRIGATED WITH SALINE DRAINAGE WATER

Abstract

There is an increasing trend in utilizing poor quality waters for irrigated agriculture due to growing municipal and environmental demands for good quality water. Suitability of poor quality water as a supplemental source for irrigation depends on the level of salinity and solute concentration in the water and the selected crop. This greenhouse study assessed the tolerance of faba beans (Vicia faba L.) to irrigation with saline drainage effluent that contains boron (B) and selenium (Se). Plants were grown in a Panoche clay loam (fine-loamy, mixed, calcareous, thermic typic Torriorthents) and irrigated with poor quality drainage effluent typical in part of the westside of California's San Joaquin Valley. The chloride/sulfate saline effluent had an electrical conductivity (EC) of 10 dS m⁻¹, a range of B concentrations from 10 to 30 mg L⁻¹, and one level of Se as selenate at 250 μg L⁻¹. After 150 days of growth at full bloom, plants were harvested and plant accumulation of B, Se, and chloride (Cl⁻) was evaluated on their effects on dry matter (DM). Dry matter production and nodulation in faba bean were significantly affected by salinity level of 10 dS m⁻¹ and slightly affected by B levels 20 mg L⁻¹ or less in the treatments. Leaf tissue accumulated the greatest concentrations of Cl⁻ (up to 8%) from the saline treatments and the greatest concentration of B (up to 1500 mg kg⁻¹ DM) and Se (up to 3.5 mg kg⁻¹ DM) from the non-saline treatments containing a range of B in solution. This study suggests that faba bean may be suitable for irrigation with drainage effluent high in B concentrations but low in salinity.

Acknowledgments