Influence of irrigation with saline reclaimed water on young grapefruits

ABSTRACT

The use of non conventional water resources, as strategy to an efficient water management, is receiving greater attention. We have designed an experiment, during four year under field conditions in a commercial grapefruit orchard located in Campotejar (Murcia, Spain). The main objective was to evaluate the effects of irrigation with saline reclaimed water compared with traditional irrigation water (Tajo-Segura water transfer) on growth, leaf mineral content, plant and soil water status, yield, and fruit quality. Na, B and Cl concentrations exceeded the recommended level in reclaimed water, for this reason, soil salts accumulation and infiltration problems were observed during last season in this treatment. Leaf B concentration was over the phytotoxic limit in reclaimed water plants, although no visual toxicity symptoms were observed. No differences were observed concerning to leaf Cl and Na concentration. The canopy volume, the number of fruits per trees, and the total yield were reduced by the effect of reclaimed water; however a tendency of higher fruit weight was observed in plants irrigated with this type of water. Salinity and boron accumulation were the main problems associated with the use of reclaimed water because although leaf toxicity levels were not observed, it could pose a risk for grapefruit production at medium and long term. The microbiological water quality was always below the threshold; therefore, the reclaimed irrigation water for grapefruit trees did not represent a microbial risk.

Keywords:

• Wastewater
• Irrigation
• Salinization
• Citrus

Acknowledgments

This study was supported by four projects granted to the authors, SIRRIMED (FP7-KBBE-2009-3-245159), CONSOLIDER-INGENIO 2010 (MEC CSD2006-0067), SENECA (11872/PI/09), and CICYT (AGL2010-17553).

Notes

The Third International Congress Smallwat11—Wastewater in Small Communities April 25–28, 2011, Seville, Spain