Abstract
A procedure for representing the effectiveness of fertilizers relative to a standard fertilizer by the estimation of substitution rates is demonstrated with yield data from a fertilizer experiment with triple superphosphate and a partially acidulated rock phosphate. The substitution rate is estimated by an iterative regression procedure and the accuracy of the estimate indicated by a 5% confidence interval.
The use of substitution rates to evaluate fertilizers depends on the assumption that the standard and alternative fertilizers differ in their effects on crop growth only because of differences in content of available nutrient. This assumption is tested as a statistical hypothesis.
Substitution rates calculated from experimental data with rates of application of the fertilizers represented in terms of chemical analysis of the fertilizers, indicate the usefulness of the analyses as measures of the available nutrient content of the fertilizers.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
AOAC (1975) Official methods of analysis, 12th edn. Washington DC: Association of Official Analytical Chemists
Colwell JD (1978) Computations for studies of soil fertility and fertilizer requirements. Slough: Commonwealth Agric Bur/Melbourne: CSIRO
Colwell JD (1983) Fertilizer requirements. In: Soils: An Australian viewpoint. Division of Soils, CSIRO, pp. 795–815, Melbourne: CSIRO/London: Academic Press
Colwell JD (1985) Fertilizing programs. I. Variability in responses of successive crops to fresh and previous applications of phosphorus fertilizer, in Australia and Brazil. Fert Res 8: 21–38
Cooke GW and Widdowson FV (1959) Field experiments on phosphate fertilizers. J Agric Sci 53: 46–63
Draper NR and Smith H (1981) Applied regression analysis. New York: Wiley
Goebert WJ Rein TA and Souza DMG (1987) An evaluation of phosphate fertilizer sources for crop production in a Cerrado soil (in preparation)
Palmer B Bolland MOA and Gilkes RJ (1979) A re-evaluation of the effectiveness of calcined Christmss Island C-grade rock phosphate. Aust J Exper Agric Anim Husb 19: 605–610
Patterson HD and Williams R (1962) The residual effects of phosphorus fertilizers on yield of arable crops: preliminary results of six rotation experiments. Exper Husb 8: 85–103, London: HMSO
Soil Survey Staff (1975) Soil taxonomy — a basic system of soil classification for making and interpreting soil surveys. Washington DC: USDA
Thomas GW and Peaslee DE (1973) Testing soil for phosphorus. In: Walsh LM and Beaton JD (eds) Soil testing and plant analysis, pp. 115–132. Madison, Wisc: American Society of Agronomy
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Colwell, J.D., Goedert, W.J. Substitution rates as measures of the relative effectiveness of alternative phosphorus fertilizers. Fertilizer Research 15, 163–172 (1988). https://doi.org/10.1007/BF01050678
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01050678