NITROGEN LEACHING LOSSES ON A VOLCANIC ASH SOIL AS AFFECTED BY THE SOURCE OF FERTILISER

ABSTRACT An intact lysimeters study was carried out to measure the potential nitrogen (N) losses onan andisoil of Southern Chile with different fertilisers. The treatments tested were: fishslurry (FS), dairy slurry (DS), potassium nitrate (IF) and a control treatment (C), with no Naddition. An equivalent amount of 150 kg of total N ha -1 was applied to each lysimeter andthen the equivalent to 1260 mm of rainfall was irrigated over a 90 days period. Leachatesamples were analysed for nitrate, nitrite, ammonia and organic N (No). Total N losseswere calculated as the product between drainage and the respective N concentration in theleachates. Lowest N losses were obtained in the control and FS treatments (66 kg N ha -1 )and the greatest amount was obtained in the IF treatment (261 kg N ha -1 ). Nitrogen wasmainly lost as nitrate and No (each was 49% of the total N losses). High soil organic matterof andisoils can be more relevant than fertiliser for N leaching losses. Palabras claves: Lodo de pescado, purines de lecheria, fertilizante inorganico, calidad deagua