Response to the primary elements, nitrogen, phosphorus and potassium, is being studies in the establishment of pastures, through 15 trial projects located in the main soil series of the provinces of Valdivia, Osorno and part of Llanquihue (Soil serie: Fresia; Osomo, Ñadi-Frutillar, Puerto Fonck and Puyehue).
Deficiency of phosphorus is acute in this zone, being this fertilizer of primary iroportance for obtaining a good pasture establishment.
Generally, nitrogen treatment helps in the development of grain crops. A marked deficiency prevails in the red day soils of the Fresia series.
Deficiency of potassium has been observed in the Ñadi-Frutillar and Puerto Fonck soils. Increases in yield have been determined when this element is applied in combination with phosphorus

1 Ingeniero Agrónomo, Subestación Experimental Barro Blanco, Osorno. Instituto de Investigaciones Agropecuarias