ISSN:
1573-0867
Keywords:
32P
;
plant P uptake
;
soil P taken up by plants
;
soil-plant relationships
;
soil test
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract A laboratory method and a laboratory index is proposed to estimate the phosphorus taken up by plants that is derived from fertilizers (Pdff). Pdff values were measured using greenhouse experiments and32P labelling technics. The laboratory index estimates the proportion of PO4-ions derived from the fertilizer in the soil solution and is measured by means of an isotopic exchange of32PO4-ion procedure. This indicator was named JCF. Two typical soil-fertilizer conditions were studied. One concerned measurement of Pdff and JCF values for freshly-applied phosphorus as diammonium phosphate (DAP) at levels of 15, 30, 45, 60 and 90 mg P kg−1 soil. The other concerned measures of Pdff and JCF values for two types of P residues previously applied in soils as concentrated superphosphate (CSP) or Gafsa rock phosphate (GRP) applied at 0 and 43.7 kg.ha−1 each year over a 15 yr period. For freshly-applied DAP a linear relationship between Pdff and JCF values was obtained over the range of 0 to 90 mg P (kg soil)−1 levels of application: JCF = 1.16 Pdff + 1.78, (r 2 = 0.98). For the P residues, JCF and Pdff values were not significantly different for a given residual treatment. However JCF and Pdff pair data for CSP treatments (56.0, 65.9) were about tenfold superior to those for GRP treatments (5.3, 4.6)). Consequently the nearly 1:1 ratio between JCF and Pdff values that was obtained for the two different soil-fertilizer conditions suggests that the proposed laboratory method can be used to predict availability of P fertilizers to plants. Thus it deserves to be considered in helping to estimate P fertilizer applications.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01048850
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