ABSTRACT
EFFECT OF FOUR LEVELS OF PHOSPHATE FERTILIZATION ON BEEF PRODUCTION OF A WHITE CLOVER-PERENNIAL RYEGRASS PASTURE. II. ECONOMIC OPTIMUM

Iván Franco P.1, Ernesto Jahn B.2, Germán Klee G.3 e Ignacio Ruiz N.2
 
A five years study on the effect of four levels of phosphate fertilization upon beef production of a white clover-ryegrass pasture was analized economically. The economic analysis was generalized using multiple regression and the sensibility to different price changes was determined. Values are expressed as chilean pesos of January 1979 ($ 34 = 1 US$). From the econometric analysis the following function for net income (NI) was obtained: In NI = 7.65 + 0.28 In (X + 1) - 0.00386 (X + 1), where NI = net income, $/ha/year, and X = maintenance phosphate fertilization, Kg P2O5/ha/year. The optimum was obtained at 72 Kg P2O5/ha/year; at this point, return on investment was 24% and the cost per kilogram of liveweight gain was $ 24.50. The sensibility tes showed that meat price changes have the highest effect on NI, while the price of phosphate is relatively unimportant. Under the present price conditions the return on investment for this type of beef production enterprise is high.
Keywords:
1Ing. Agr., Economisgta Agrícola, Estación Experimental Quilamapu, Instituto de Investigaciones Agropecuarias (INIA), Casilla 426, Chillán, Chile. 2Ing. Agr., Ph.D., Estación Experimental Quilamapu, Instituto de Investigaciones Agropecuarias (INIA), Casilla 426, Chillán, Chile.3Ing. Agr., Subestación Experimental Humán, Instituto de Investigaciones Agropecuarias (INIA), Casilla 767, Los Angeles, Chile.