A two year NP fertilizer trial in wheat ha.s been completed in 7 Experiment Stations of the Departamento de Investigaciones Agrícolas. These Stations are aH situated south of Sahtiago. Yields responded remarkably from applications of both fertilizers applied. Generally the effeet of the two elements was independent, but there were a few cases of interaction.
The maximun average effect was obtained at the maximun rates used: 64 Kg. of N per hectarea plus 160 Kg. of P2O5 per hectarea. Yields in this case were of 10.3 metric quintals per héctarea greater than the average yield of 21,9 metric quintals per hectarea without fertilizer.