Nitrogen Loss by Ammonia Volatilization in Cultivation of Olive Orchards Fertilized with Compost

Abstract

This study concentrated on drip-irrigated olive trees on Calcisols, Cambisols, and Luvisols. The olive trees were fertilized with compost spread in bands about 30 cm from each tree line and incorporated with a subsoiler. The volatilization of NH₃ was quantified using a semi-open static system, with polyurethane discs impregnated with 1N H₂SO₄. The accumulated loss of NH₃ was calculated by adding up the daily flow of NH₃ during the 10-day measurement period and comparing it to a control treatment. The total nitrogen volatilized during the study period varied with the type of soil, and was highest in the 2018 campaign, with 2.24, 2.05 and 1.66 kg ha^–1 in Calcisols, Cambisols, and Luvisols, respectively, representing losses of 3.50, 3.20, and 2.59% of the total N incorporated. Variables with a significant effect on volatilization were rainfall, potential evaporation (closely related to temperature) and soil type, with higher significance in Luvisols.