Assessment of a newly implemented irrigated area (Lerma Basin, Spain) over a 10-year period. II: Salts and nitrate exported

摘要: Irrigated agriculture impacts the quality of water bodies receiving irrigation return flows. The leaching salts and nitrate from Lerma Basin (7.38 km2), a newly-implemented pressurized irrigated area in Ebro (Spain), was assessed this study for hydrological years 2004–2013, covering before (2004–2005), during (2006–2008) after (2009–2013) implementation irrigation. concentration were measured all components balance amounts these pollutants coming surface (352 ha) estimated. Besides, salt contamination indices computed. Under unirrigated conditions, studied exported 1.89 Mg ha−1 year−1 11.4 kg nitrate-nitrogen, respectively. These increased to 3.51 30.8 nitrate-nitrogen Salt (SCI NCI, respectively) by factor three reaching values 0.96 [Mg year−1]/[dS m−1] 0.12, Despite being well under threshold considered more sustainable areas < 2.0 NCI 0.2), it would be advisable improve management increase use decrease leaching. Complementary measures such as adjusting fertilization rates temporal crop necessities or catch crops may prove useful.