The effectiveness of different sources of the same nutrient should be compared using plots of yield versus fertilizer applied to find how much more of the less-effective source is needed to provide the same yield. This gives the same result as measuring the relative response to the two fertilizers — provided response is defined as the instantaneous slope of the yield-fertilizer curve rather than the yield produced by a given amount of fertilizer. In most cases, and especially for immobile nutrients, the relative effectiveness, measured as suggested, will not be affected by the level of application. It is reasonable to assume this simple case until this assumption can be disproved — rather than assuming a more complicated case in the first instance.
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Barrow NJ and Campbell NA (1972) Methods of measuring residual value of feritilizers. Aust J Exp Agric Anim Husb 12, 502–510
Black CA and Scott CO (1956) Fertilizer evaluation. 1. Fundamental principles. Soil Sci Soc Amer Proc 20, 176–179
Bolan NS, Robson AD and Barrow NJ (1983) Plant and soil factors including mycorrhizal infection causing sigmoidal response of plants to applied phosphorus. Plant and Soil 73, 187–201
Bolland MDA and Bowden JW (1984) The initial and residual value for subterranean clover of phosphorus from crandallite rock phosphates, apatite rock phosphates and superphosphate. Fert Res 5, 295–307
Brennan RF, Gartrell JW and Robson AD (184) Reaction of copper with soil affecting its availability to plants. III. Effect of incubation temperature. Aust J Soil Res 22, 165–171
Colwell JD (1983) Fertilizer requirements. In: Soils: An Australian Viewpoint (Ed. CSIRO Div. Soils). CSIRO: Melbourne/Academic Press
Engelstad OP, Jugsujinda A and De Datta S (1974) Response by flooded rice to phosphate rocks varying in citrate solubility. Soil Sci Soc Amer Proc 38, 524–529
van Burg PFJ (1963) The agricultural evaluation of nitrophosphates with particular reference to the direct and cumulative phosphate affects, and the interaction between water solubility and granule size. The Fert Soc Proc No. 75
van Burg PFJ, Dilz K and Prins WH (1982) Agricultural value of various nitrogen fertilizers. Nethl Nitrogen Tech Bull No. 13
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Barrow, N. Comparing the effectiveness of fertilizers. Fertilizer Research 8, 85–90 (1985). https://doi.org/10.1007/BF01048909
- agronomic effectiveness
- fertilizer response
- relative effectiveness
- substitution rates