Abstract
The agronomic potential of four partially acidulated rock phosphates (PARP) made from a moderate reactive phosphate rock at 30 or 60 percent acidulation either by sulfuric acid alone or by combination of sulfuric and phosphoric acids was compared with that of monocalcium phosphate (MCP) and ground rock phosphate (RP) on a calcareous soil (Typic Hapluquent, pH 8.5) in greenhouse. Dry weight and P accumulation of successive cuttings of ryegrass shoots were used to evaluate the relative agronomic potential of these fertilizers. Results indicated that PARPs of higher water-soluble P content had similar immediate effectiveness as MCP at two earlier cuttings, however, they produced significantly less total dry matter than MCP did in overall six successive cuttings. PARPs were constantly inferior to MCP in terms of P uptake by plant in all the six cuttings. When compared to RP, on the other hand, PARPs had markedly higher relative effectiveness. RP itself affected neither the dry matter production nor the P uptake by plant as compared to control treatment.
Fractionation of residual inorganic P in the soil samples at two time intervals during plant growth indicated that MCP-P mainly transformed to dicalcium phosphate and octacalcium phosphate, and to a less extent to Fe and Al associated P. These forms of P had significant correlation with P accumulation by plant. Raw RP did not subject to transformation after applied to the soil regardless the duration of culture time. No obvious dissolution of unreacted RP in PARP materials was detected. Plant dry matter production and P uptake were mainly correlated with water-soluble P added with the fertilizers. It is suggested from the experiment that although partial acidulation could substantially improved the effectiveness of rock phosphate and the immediate effect of the fertilizer was competitive with MCP, application of PARP to calcareous soils is only of short-term benefits; in a long run this fertilizer is not considered as a desirable source of P in calcareous soils since the unacidulated part in the fertilizer was unable to be solubilized in the alkaline conditions.
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References
Bell LC and Black CA (1970) Transformation of dibasic calcium phosphate dihydrate and octacalcium phosphate on slightly acid and alkaline soils. Soil Sci Soc Am Proc 34: 583–587
Bolan NS, Hedley MJ, Harrison R and Braithwaite AC (1990) Influence of manufacturing variables on characteristics and the agronomic value of partially acidulated phosphate fertilizers. Fert Res 26: 119–138
Bolland MDA, Glencross RN, Gilkes RJ and Kumar V (1992) Agronomic effectiveness of partially acidulated rock phosphate and fused calcium-magnesium phosphate compared with superphosphate. Fert Res 32: 169–183
Chinese Academy of Agriculture Science (1986) Fertilizer Planning of China. China Agriculture Science Press, Beijing. 90p
Garbouchev IP (1981) The manufacture and agronomic efficiency of a partially acidulated phosphate rock fertilizer. Soil Sci Soc Am J 45:970–974
Gu YC, Li AR and Jiang BF (1990) Phosphorus supply ability of different forms of phosphate on calcareous soils. Turang (Soils) 23: 296–301 (In Chinese)
Gu YC, Jiang BF and Lu RK (1984) Effect of weathering on the transformation and availability of phosphorus in different fractions of particle size of main soils of China. Acta Pedologica Sinica 21: 134–143 (In Chinese)
Hagin J and Katz S (1985) Effectiveness of partially acidulated phosphate rock as a source to plants in calcareous soils. Fert Res 8: 117–127
Hammond LL, Chien SH and Mokwunye AV (1986) Agronomic value of unacidulated and partially acidulated phosphate rocks indigenous to the tropics. Adv Agron 40: 89–140
Hsu PH (1982) Crystallization of variscite at room temperature. Soil Sci 133: 305–313
Institute of Soil Science, Academia Sinica (1992) Agronomic effectiveness of partially solubilized phosphate rocks. Paper presented on the Sino-France Workshop on Utilization of low to medium grade phosphate rocks for producing phosphate fertilizers. Beijing. 9p
Jiang B and Gu Y (1989) A suggested fractionation scheme for inorganic phosphorus on calcareous soils. Fert Res 20: 159–165
Lindsay WL and Stephenson HF (1959) Nature of the reactions of monocalcium phosphate monohydrate in soils: I. The solution and precipitation reactions involving iron, aluminium, manganese, and calcium. Soil Sci Soc Am Proc 23: 18–32
Logan TJ and McLean EO (1977) Diffusion of32P from partially acidulated rock phosphate. Soil Sci 123: 202–206
McLean EO (1956) Factors affecting yields and uptake of P by different crops. II. Rock phosphate and superphosphate separate and in combination under extended cropping. Soil Sci 82: 181–192
McLean EO and Wheeler RW (1964) Partially acidulated rock phosphate as a source of phosphorus to plants: I. Growth chamber studies. Soil Sci Soc Am Proc 28: 545–550
Mokwunye AU and Chien SH (1980) Reactions of partially acidulated phosphate rock with soils from the tropics. Soil Sci Soc Am J 44: 477–482
Romheld V and Marschner H (1986) Evidence for a specific uptake system for iron phytosiderophores in roots of grasses. Plant Physiol 80: 175–180
Stephen RC and Condron LMC (1986) An assessment of the agronomic efficiency of partially acidulated phosphate rock fertilizers. Fert Res 10: 269–282
Takagi S, Nomoto K and Takmoto T (1984) Physiological aspect of mugineic acid, a possible phytosiderophore of graminaceous plants. J Plant Nutr 7: 469–477
Taylor AW, Lindsay WL, Huffman EO and Gurney EL (1963) Potassium and ammonium taranakites, amorphous aluminum phosphate and variscite as source of phosphorus for plants. Soil Sci Soc Am Proc 27: 148–151
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Xiong, L.M., Lu, R.K. & Truong, B. An evaluation of the agronomic potential of partially acidulated rock phosphates in calcareous soil. Fertilizer Research 38, 205–212 (1994). https://doi.org/10.1007/BF00749693
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DOI: https://doi.org/10.1007/BF00749693