An Economic Study of Optimum Fertiliser Applications and Plant Population in Maize

Abstract

TIIE DETERMINATION of the most profitable level of maize production involves the relationship between two sets of independent relationships, viz., physical production relationships which are determined by physical phenomena, and the economic relationships which are influenced by economic conditions. Physical relationships do have some economic implications, but they alone cannot specify the optimum quantity of each variable resource which would result in yields giving maximum profits. The amount of the factor inputs which will result in maximum profits can be determined in advance only when the relevant physical and economic relationships are known before the production period begins, and if there is absolute control over these factors during the production period. Of course, this is unrealistic and at best complete information can only be approached by a prediction or approximation of future happenings based itpon past experience.Given the physical relationships, the combination of the factors of production associated with maximum profits may be subjected to many modifications. These modifications result from variatioos in economic conditions such as factor and product prices which aNect the economic relationships (factor-factor and factorproduct price ratios). These in turn affect the most profitable levels and combinations of the factors of production. The estimate of optitnuin resource combinations in this study will be based on current and near current price ratios. Changing price relationships would alter the optimum combination. An attempt will be made to show the effect of cliaiigitig price ratios upon the most profitable lcvels of fertiliser application atid plant population. PROCEDURE Design cf ErperitritwtThe economic study described bclow was imposed upon an agronomic field experinleiit laid out at the Cedara College of Agriculture and Research Station. 233

Derivation of Appropriate Functions for the Economic Analysis of Maize Yield Responses to Fertilizer and Rainfall Variations at Dundee

“…South African researchers have also employed the quadratic and square-root functions. Comparative studies show that these polynomials can adequately represent the relationship between maize grain yields and the level of fertilization (Allison, 1977;Farina eta!, 1975;Farina et al, 1980;Farina and Mapham, 1973;Kassier and Mallet, 1966;Korentajer et al, 1987;Mapham, 1975;Mapham and Farina, 1974;Nienaber and Groenewald, 1979;Nieuwoudt and Behrmann, 1976).…”

“…A decision of profound consequence in maize production centres on the determination of fertilization rates. Kassier and Mallet (1966) point out that this involves two sets of relationships, namely physical production relationships and those economic principles governing production and resource allocation. The correct amount of fertilizer, for a specific set of conditions, will depend on: (a) the expected yield; (b) the expected price of fertilizer and maize; (c) the capital position of the farmer, and (d) the probable returns from alternative uses of this capital (Farina et al, 1975).…”