Abstract
A pot trial was conducted to determine the influence of phosphate rock (PR) reactivity and granule size on the effectiveness of biosuper. Perennial ryegrass was grown as the test crop for 9 months in a volcanic ash soil of pH 5.4. The PRs used were North Carolina (NC) (reactive) and Florida (Fl) (less reactive). Single superphosphate was used as the standard fertilizer. The fertilizers were added at 6 rates 3 mm below the soil surface.
The dry matter yield and phosphate uptake data indicated that the effectiveness of the fertilizers were in the order of NC/S (biosuper indicated by adding S to the PR names) = superphosphate > NC > F1/S > F1 > control. The performance of biosupers and PRs relative to superphosphate, improved with time. The effectiveness of NC/S increased by 18–30% and that of F1/S by 50–70%, depending on the rate of application, in comparison with addition as PR granules. Plant phosphate uptake and soil Olsen bicarbonate extractable phosphate values indicated that the increase in yield in biosuper treatments was due to enhanced phosphate supply, caused by the oxidation of sulphur to sulphuric acid and the subsequent reaction of the acid with the PRs.
Increasing the NC/S granule size from 0.2–0.5 to 1–2 mm range resulted in a small but significant decrease in effectiveness. However, the calculated yield maxima were the same. The size of the granules did not make significant difference with F1/S.
Olsen bicarbonate extractable phosphate values increased by 140 to 310% and 140 to 330% respectively when NC and Fl were added as biosupers compared to addition as PR granules. The values for superphosphate decreased rapidly with time and were less than those for biosupers five months after addition 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
Alston AM and Chin KW (1974) Response of subterranean clover to rock phosphates as affected by particle size and depth of mixing in the soil. Aust J exp Agric Anim Husb 14, 649–55
Basson WD (1976) Nitrogen and phosphorus determinations in animal feeds on a continuous flow system. Lab Practice 25, 763–65
Barrow NJ and Shaw TC (1976) Sodium bicarbonate as an extractant for soil phosphate. I. Plant and Soil 16, 91–107
Chien SH (1977) Dissolution rates of phosphate rocks. Soil Sci Soc Am J 41, 656–57
Chien SH and Black CA (1976) Free energy of formation of carbonate apatites in some phosphate rocks. Soil Sci Am J 40, 234–39
Huffman EO (1962) Reactions of phosphate in soils: Recent research of TVA. The Fert Soc Proc 71 (London)
Khasawneh FE and Doll EC (1978) The use of phosphate rock for direct application to soils. Adv Agron 30, 159–206
Jennrich R (1977) In Dixon WJ ed. BMDP biomedical computer programmes, P. series. Univ Calif press, pp 464–83
NZ Soil Bureau (1968) Soils of New Zealand. NZ Soil Bureau Bull 26
Partridge IJ (1980) The efficacy of biosupers made from different forms of phosphate on forage legumes in hill land in Fiji. Trop Grasslands 14, 87–94
Rajan SSS (1981) Use of low grade phosphate rocks as biosuper fertilizer. Fert Res (in press)
Rajan SSS and Edge EA (1980) Dissolution of granulated low grade phosphate rocks, phosphate rocks/sulphur and superphosphate in soil NZ J agric Res 23, 451–56
Roberts OT and Evans L (1979) Plant response and solubility of phosphates. NZ Fert Man Res Assn, 7th Tech Conf, pp 305–320
Saunders WMH (1975) Phosphate retention by New Zealand soils and its relationship to free sesquioxides, organic matter, and other soil phosphates. NZ J agric Res 8, 30–57
Swaby RJ (1975) Biosuper-biological superphosphate. In McLachlan K.D. ed. Sulphur in Australasian agriculture. Sydney Univ press, pp 213–20
Watanabe GS and Olsen SR (1965) Test of an ascorbic acid method for determining phosphorus in water and NaHCO3 extracts from soil. Soil Sci Soc Am Proc 29, 677–78
Watkinson JH (1969) The kinetics of ion exchange in soil. PhD Thesis, Victoria University of Wellington, New Zealand
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rajan, S. Influence of phosphate rock reactivity and granule size on the effectiveness of ‘biosuper’. Fertilizer Research 3, 3–12 (1982). https://doi.org/10.1007/BF01063404
Issue Date:
DOI: https://doi.org/10.1007/BF01063404