ABSTRACT


Gotardo Schenkel S.1, Pedro Baherle V.2, Horacio Floody A.3 y Mauricio Gajardo M.4
 

The yield responses of ray-grass sown in pot experiments with three fertilizations -N, NP and NPKS- are studied on fifteen soil samples from the Aisén province.
The low soil fertility cannot be improved conveniently by nitrogen fertilizers alone, particularly when samples are phosphorous deficient.
A considerable increase in the yield indexes in observed by the NP addition to the soil. there are exceptions that proceed from samples in which other nutrients than phosphorous are more serious deficiencies.
There is an advantage in the use of NPKS fertilization as compared with the other two treatments, for all soils. By means of it, the fertility levels reached are similar to the one obtained by complete manuring. The worst responses to NPKS are found in soils that have problems with magnesium and micronutrients.
The results from pot experiments are compared with the information given by some field trials.

Keywords:
1Ing. Químico, Programa de Suelo, Estación Experimental Carillanca, Instituto de Investigaciones Agropecuarias (INIA), Casilla 58-D, Temuco, Chile.
2Ing. Agr., Programa Fertilidad de Suelo, Estación Experimental Carillanca, INIA.
3Laboratorista Químico, Programa Fertilidad de Suelo, Estación Experimental Carillanca, INIA.
4Ayudante de Laboratorio, Programa Fertilidad de Suelo, Estación Experimental Carillanca, INIA.