Análise da produtividade marginal e uso dos recursos na cultura de arroz, no município de Inhumas, estado de Goiás

Resumo

This study seeks to estimate a production for rice such that the allocation of resources dedicated to this crop may be analyzed.

The production of rice is of extreme importance for the state of Goias as well as for all of Brazil. Inhumas, one of the principal centers of production in Goias,was chosen as the area to be studied.

Comparing rice with other principal products, its contriburion to the wealth of the nation may be verified.

The data used inthis study were collected by SUESCUN GOMES (9) in 1967 in ten selected counties (municipios). The sample was composed of 42 questionnaires obtained at random indirect farmer interviws. Based onthe sample data, the principal production variables to be included in the study were selected.

A Cobb-Douglas production function was estimated in logarithims with ordinary least squares.

The following equation was obtained: 

log Y = 0. 912068 + 0.594520  log X1 + 0.272721  log X2 +

+ 0. 032744  log X3 + 0.063708  log X4 

where:

Y = rice prodution in sacks of 60 kilograms

X1 = hectares of land cultivated with rice

X2= labor in man/days

X3 = work animals in animal/days

X4 = general expenses in Cr$

The coefficientes of X1 and X2 were significantat the 1% and 10% level respectively. The others were not significant. There exists a high simple correlation between the dependant variables X1 and X2,as well as ahigh intercorrelation between X1 and X2.

The returns to scale encountered were considered constant. The ratio between the value of the marginal product and the price was greater than one for all variables. Marginal products, measured at the geometric means of sample use levels, were 5. 86 ha. for land (X1); 203. 5 man/days for labor (X2); 7.5 animal/days of work animals (X3); and, Cr$ 91.00 for general expenses (X4). Farmers are obtaining a reasonable profit per unit of area.

An analysis of optimal use levels for each resource considered in isolation indicated that the following increases should be made: a) land to 51. 43 ha. ; b) labor to 264. 00 man/ days; c) work animals to 13. 32 animal/days; and d) general expenses to Cr$ 116. 02.

All of the marginal rates of substitutionwere negative indicating that all factors of production consideredwere substitutes.

Finally, the study indicates thatvarious research projects should be mounted in the area studied in order to assist in the formulation of programs for the various organs involvee in the region.