Determination of economic optimum fertilizer levels using discrete and continuous analytical methods
Tanner, D.G.
Determination of economic optimum fertilizer levels using discrete and continuous analytical methods - Addis Ababa (Ethiopia) CIMMYT : 1999 - Printed
The determination of economic optimum fertilizer rates is fundamental to profitable bread wheat (Triticum aestivum) production. However, the derivation of economic optimum nutrient rates is complex and is dependent upon fluctuating nutrient and grain prices and changing crop management practices. Economic optimum N and P205 nutrient rates were determined following discrete and continuous analytical methods using data generated in a series of on-farm fertilizer trials conducted in Ethiopia during 1988-90 and 1995-97 across a range of agro-ecologies. The data were first subjected to ANOVA and then regression coefficients derived from response surface equations were used to determine the continuous economic optimum fertilizer rates. Discrete analysis of the actual N-P205 treatments following partial budget methodology was used to determine the discontinuous economic optimum rates. Optimum N and P205 levels for each agro-ecological zone were established based on specified ranges for nutrient and grain prices using both methods. The optimum rates generated by the two analytical methods lacked close agreement for the obvious reason that the continuous method is based on a smoothed regression curve while the discrete method is based on actual data points. However, the relative ratios of N and P205 rates were generally consistent between the two methods. The use of regression-derived response coefficients in continuous economic analysis facilitates the construction of dynamic and robust recommendation tables for dissemination to extension staff. Furthermore, the continuous method facilitates interpolation thereby accommodating intermediate price levels.
English
92-9146-058-3
Crop management
Economic analysis
Ethiopia
Fertilizer application
Fertilizers
Prices
Production factors
Triticum aestivum
CIMMYT
Determination of economic optimum fertilizer levels using discrete and continuous analytical methods - Addis Ababa (Ethiopia) CIMMYT : 1999 - Printed
The determination of economic optimum fertilizer rates is fundamental to profitable bread wheat (Triticum aestivum) production. However, the derivation of economic optimum nutrient rates is complex and is dependent upon fluctuating nutrient and grain prices and changing crop management practices. Economic optimum N and P205 nutrient rates were determined following discrete and continuous analytical methods using data generated in a series of on-farm fertilizer trials conducted in Ethiopia during 1988-90 and 1995-97 across a range of agro-ecologies. The data were first subjected to ANOVA and then regression coefficients derived from response surface equations were used to determine the continuous economic optimum fertilizer rates. Discrete analysis of the actual N-P205 treatments following partial budget methodology was used to determine the discontinuous economic optimum rates. Optimum N and P205 levels for each agro-ecological zone were established based on specified ranges for nutrient and grain prices using both methods. The optimum rates generated by the two analytical methods lacked close agreement for the obvious reason that the continuous method is based on a smoothed regression curve while the discrete method is based on actual data points. However, the relative ratios of N and P205 rates were generally consistent between the two methods. The use of regression-derived response coefficients in continuous economic analysis facilitates the construction of dynamic and robust recommendation tables for dissemination to extension staff. Furthermore, the continuous method facilitates interpolation thereby accommodating intermediate price levels.
English
92-9146-058-3
Crop management
Economic analysis
Ethiopia
Fertilizer application
Fertilizers
Prices
Production factors
Triticum aestivum
CIMMYT