Effect of irrigation frequency and water quality on N losses from vertisols

A field study was conducted in a drip-irrigated Avocado orchard planted on a wastewater-degraded montmorillonite clay soil in northern Israel. Fertigation/irrigation frequency (daily, or every 2 or 3 days) and water quality (TWW, fresh, 50%TWW+50% fresh) both affected N2O emission and nitrate leaching.

Irrigation with freshwater showed the lowest N2O emissions and nitrate leaching. Scoria filled aeration trenches (30 x 30 cm) showed both positive and negative effects on N losses, which depended on the irrigation/rain intensity. We show that the irrigation water quality and the irrigation frequency should be accounted for in future attempts to mitigate N2O emissions and nitrate leaching.