The residual value of rock phosphate and superphosphate from field sites assessed by glasshouse bioassay using three plant species with different external P requirements

1992 ◽  
Vol 32 (2) ◽  
pp. 195-207 ◽  
Author(s):  
Vijay Kumar ◽  
R. J. Gilkes ◽  
M. D. A. Bolland
Keyword(s):  
Plant Species ◽  
Rock Phosphate ◽  
Residual Value

Evaluation of phosphate fertilizers: II. Residual value of nitrophosphates, Gafsa rock phosphate, basic slag and potassium metaphosphate for potatoes, barley and swedes grown in rotation, with special reference to changes in soil phosphorus status

1968 ◽  
Vol 70 (2) ◽  
pp. 139-156 ◽  
Author(s):  
G. E. G. Mattingly
Keyword(s):  
Rock Phosphate ◽  
Crop Yields ◽  
Soil Analysis ◽  
Soil Phosphorus ◽  
P Uptake ◽  
Barley Grain ◽  
Yield Response ◽  
Residual Value ◽  
Basic Slag ◽  
Phosphate Fertilizers

SUMMARYThe residual value of three nitrophosphates, potassium metaphosphate, basic slag and rock phosphate was compared with that of superphosphate in two experiments with potatoes, barley and swedes grown in rotation. The residual value of the fertilizers was also compared with that of (a) six cumulative annual dressings of superphosphate supplying either one-half or the same total amounts of phosphate and (b) single fresh applications of superphosphate applied once in each rotation. Yields and phosphorus uptakes are discussed in relation to the amounts of soil phosphate soluble in 0·5 M-NaHCO3.In the first rotation residues of rock phosphate produced about 1 ton/acre less potato tubers than residues of other fertilizers and cumulative annual applications of superphosphate produced 0·6–0·9 tons/acre less tubers than all residues except rock phosphate. In the second rotation residues of fertilizers increased tuber yields less than cumulative dressings of superphosphate. Over two rotations mean yields from residues and from cumulative dressings were the same. Mean yields of barley over two rotations were 1–3 cwt/acre greater from residues than from cumulative annual dressings; the residual value of the different phosphates was the same. For swedes residues from the alternative phosphates, including basic slag and rock phosphate, were equivalent to those from superphosphate and gave the same mean yields as six cumulative dressings of superphosphate broadcast at planting.Average residual values of alternative phosphate fertilizers, calculated from (a) yield response, (b) P uptake, and (c) soil analysis were: superphosphate, 100; nitrophosphates, 100–102; potassium metaphosphate, 95; basic slag, 94; Gafsa rock phosphate, 92. Mean percentage ‘fresh’ superphosphate equivalents of residues from all fertilizers were 17 and 26% after the first rotation and 11 and 15% after the second rotation for potatoes and swedes respectively.The percentage of the total variance in crop yields accounted for by linear regression on NaHCO3-soluble P ranged from 38 to 70% for potatoes, 9 to 28% for barley grain and 42 to 92% for swedes. Mean yields of the crops increased by 0·24 ± 0·037 tons/acre (potatoes), 0·22 ± 0·08 cwt/acre (barley) and 1·16 ±0·148 tons/acre (swedes) for each ppm NaHCO3-soluble phosphorus in the soil at harvest.

Residual value of superphosphate and rock phosphate on an acid soil I. Yields and phosphorus uptakes in the field

1963 ◽  
Vol 60 (3) ◽  
pp. 399-407 ◽  
Author(s):  
G. E. G. Mattingly ◽  
F. V. Widdowson
Keyword(s):  
Isotope Dilution ◽  
Rock Phosphate ◽  
Acid Soil ◽  
P Uptake ◽  
Residual Effects ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Residual Value ◽  
Phosphate Fertilizers ◽  
Rye Grass

1. A field experiment on an acid soil long in arable cropping at Rothamsted measured residual effects of superphosphate, applied at several rates, and Gafsa rock phosphate applied at a single rate. Residues were valued after 1 year with barley, and after 2 years with rye-grass. In each year, the value of the residues was related to yields from fresh superphosphate dressings taken as standards. ‘Percentage fresh superphosphate equivalents’ of the residues were determined using yields and P uptakes of both crops. An isotope dilution method with 32P was also used with barley. The experiment was continued for 2 further years without applying phosphate fertilizers, to measure yields and P uptakes from the residues and yields and P uptakes from rock phosphate relative to superphosphate.2. ‘Percentage fresh superphosphate equivalents’ of residues of superphosphate for barley varied with the growth of the crop and with the method used to calculate them. They were 21–24%6 weeks after sowing, measured from yield, P uptake or isotope dilution. At harvest, they were 26% from yield, 43% from P uptake and 49% by isotope dilution. ‘Percentage fresh superphosphate equivalents’ 6 weeks after sowing increased with the rate of superphosphate but at harvest were independent of rate. ‘Percentage superphosphate equivalents’ of Gafsa rock phosphate were much smaller; they increased from 2–3% 6 weeks after sowing to 7–12% at harvest.3. With rye-grass ‘percentage fresh superphosphate equivalents’ of residues of superphosphate applied either 1 or 2 years previously also varied with growth. All methods of valuation showed that residues were about twice as effective after 1 year as after 2 years in the soil. ‘Percentage fresh superphosphate equivalents’ derived from P uptake remained constant during growth and were 37–38% for superphosphate applied 1 year before and 18–20% for superphosphate applied 2 years before. Values derived from rye-grass yields decreased during growth from 76 to 45% (1-year residues) and from 38 to 21% (2-year residues).4. After cropping with barley for 2 more years, there was little difference between yields or P uptakes from equal amounts of superphosphate whether applied 3 or 4 years previously. Residues from rock phosphate were almost equivalent to those from superphosphate after 3–4 years.5. Apparent recoveries of superphosphate, as percentages of the amount applied, decreased with rate. The apparent recovery of P by crops in 5 years was about 21% from superphosphate and about 10% from rock phosphate when both were applied at 3·0 owt. P2O5 per acre.

The cation exchange capacity of plant roots, and its relationship to the uptake of insoluble nutrients

1961 ◽  
Vol 12 (5) ◽  
pp. 755 ◽  
Author(s):  
CJ Asher ◽  
PG Ozanne
Keyword(s):  
Cation Exchange ◽  
Plant Species ◽  
Cation Exchange Capacity ◽  
Rock Phosphate ◽  
Root Systems ◽  
Exchange Capacity ◽  
Nitrogen Supply ◽  
Plant Roots ◽  
Rapid Technique ◽  
Calcium And Phosphorus

The cation exchange capacity (C.E.C.) of the roots of 20 plant species was measured by a rapid technique not involving toxic reagents or harmful temperatures. Significant differences between the root C.E.C. of various species were found, and with three exceptions, legumes > herbs > grasses. Nitrogen supply had little effect on the legumes and herbs, but significantly increased the C.E.C. of two grasses. The concentrations of calcium and phosphorus in the tops of plants utilizing rock phosphate were each positively correlated with root C.E.C. The concentration of phosphorus was not greater in the tops of plants with relatively large root systems.

The intial and residual effects of superphosphate and rock phosphate for sorghum on a lateritic red earth

1963 ◽  
Vol 14 (6) ◽  
pp. 785 ◽  
Author(s):  
W Arndt ◽  
GA McIntyre
Keyword(s):  
Rock Phosphate ◽  
Residual Effects ◽  
Residual Value ◽  
Clay Loam ◽  
Initial Value ◽  
Long Run ◽  
Highly Effective ◽  
Red Earth ◽  
Sorghum Production

The initial and residual effects of superphosphate and rock phosphate with sorghum were recorded on Tippera clay loam a lateritic red earth at Katherine, N.T. Both forms of phosphate were highly effective as initial broadcast applications and as residues. Initially, superphosphate was superior to rock phosphate on a weight per acre basis. For superphosphate the residual value left after 1 year was 50% of the initial value, and after 7 years about 8%. For rock phosphate the residual value after 7 years was about 66–70% of the initial value. The data have been extrapolated to give rough estimates of the value to complete exhaustion of the residue. These estimates suggest that for both superphosphate and rock phosphate, regular annual dressings of 1 cwt and of 2 cwt will give in the long run at least 80% and 95% respectively of the sorghum production possible with phosphate not limiting.

The value of Nauru rock phosphate as a source of phosphorus for some tropical pasture legumes

1971 ◽  
Vol 11 (52) ◽  
pp. 532 ◽  
Author(s):  
WW Bryan ◽  
CS Andrew
Keyword(s):  
Medicago Sativa ◽  
Rock Phosphate ◽  
Residual Value ◽  
Tropical Pasture ◽  
Single Superphosphate ◽  
Pasture Legumes ◽  
Yield Responses ◽  
Moderate Yield ◽  
Indigofera Spicata

Using soils known to be grossly deficient in phosphorus, and with a basal dressing of sulphur (and other deficient nutrients) plants were grown in pots and in the field with single superphosphate or Nauru rock phosphate. The plants fell into two groups, those that gave moderate yield responses to rock phosphate as compared with superphosphate (Lotononis bainesii, Stylosanthes guyanensis, Centrosema pubescens, Indigofera spicata, and Medicago sativa) and those whose response to rock phosphate was poor (Desmodium uncinatum and Phaseolus lathyroides). In no case was the response to rock phosphate as good as that to superphosphate, even when twice as much phosphorus, in the form of rock phosphate, was applied. The residual value of rock phosphate was low with Desmodium, high with Lotononis, but never as high as that of superphosphate.

The effectiveness of rock phosphate fertilisers in Australian agriculture: a review

1988 ◽  
Vol 28 (5) ◽  
pp. 655 ◽  
Author(s):  
MDA Bolland ◽  
RJ Gilkes ◽  
MFD' Antuono
Keyword(s):  
Soil Ph ◽  
Rock Phosphate ◽  
Field Experiments ◽  
Relative Effectiveness ◽  
Complete Response ◽  
Annual Rainfall ◽  
Residual Value ◽  
Response Curves ◽  
Rock Phosphates ◽  
Mean Annual Rainfall

Plant responses to apatite rock phosphates and Calciphos, a calcined calcium iron-aluminium rock phosphate fertiliser, have been measured in many pot and field experiments in Australia, but there is no consistent view of the agronomic effectiveness of these fertilisers. Quantitative indices of the effectiveness of freshly applied rock phosphates relative to freshly applied superphosphate (relative effectiveness or RE values) have been calculated from the data for 164 Australian pot and field experiments on the basis of the substitution value of the rock phosphates for superphosphate. RE values range from <0.1 to 2.5, with the mean value for apatite rock phosphates being 0.26 compared with 0.42 for Calciphos. Statistical analysis of the data demonstrate that variations in RE values were primarily due to systematic differences in experimental design and fertiliser solubility, and not to differences in soil pH, plant species, the capacity of the soil to adsorb P and mean annual rainfall. All RE values >0.4 were obtained from experiments in which only 1 or 2 levels of fertiliser were applied to soils that were poorly responsive to applied P; thus it was not possible to define the complete response curves required to obtain precise values of RE. In most cases, RE values were < 0.4 for experiments in which several levels of fertiliser P were applied to highly P-responsive soils so that complete response curves were defined and precise values of RE estimated. The effectiveness of previously applied rock phosphate (i.e, residual value) remained low and approximately constant for several years after application, being 5-30% as effective as freshly applied superphosphate for the various experiments. The corresponding average value of the relative effectiveness of superphosphate declined by 40% in the first year after application, by a further 15% in the second year, and by a further 30% over the remaining 6 years. However, the magnitude of these declines in relative effectiveness differed substantially between individual sites. The residual value of both the superphosphate and rock phosphate fertilisers appears not to have been systematically influenced by soil type, soil pH, the capacity of the soil to adsorb P, mean annual rainfall, and whether the fertilisers were topdressed or were incorporated. However, there is a need for additional experiments to investigate the influence of these factors on fertiliser effectiveness. It is concluded that, on the basis of published data, rock phosphate fertilisers cannot be regarded as economic substitutes for fertilisers containing water-soluble P for most agricultural applications in Australia. This is because, relative to freshly applied superphosphate, the fertiliser effectiveness of rock phosphates is low in the year of application and it remains low in subsequent years so that uneconomical, very high rates of application of rock phosphate are required.

Residual value of superphosphate and Queensland rock phosphate for serradella and clover on very sandy soils as assessed by plant growth and bicarbonate-soluble phosphorus

1987 ◽  
Vol 27 (2) ◽  
pp. 275 ◽  
Author(s):  
MDA Bolland ◽  
RJ Gilkes ◽  
DG Allen ◽  
MF D'Antuono
Keyword(s):  
Rock Phosphate ◽  
Maximum Yield ◽  
Sandy Soils ◽  
Subterranean Clover ◽  
Soil Samples ◽  
Spline Functions ◽  
Soil Test ◽  
Residual Value ◽  
Fertiliser Application ◽  
Separate Calibration

Superphosphate (0-0.4 t/ha P) and Queensland rock phosphate (0-20 t/ha P) were incorporated into the top 10 cm of very sandy soil near Esperance, W.A. The effectiveness of the fertilisers for pastures was calculated from dry herbage yields of yellow serradella, slender serradella and subterranean clover. Soil samples were collected just after fertiliser application and at intervals up to 2.5 years for measurement of bicarbonate-extractable phosphorus (soil test), which was related to plant yield. Results for all 3 species were very similar in response to superphosphate. The effectiveness of superphosphate decreased by about 50% between years 1 and 2, and by a further 25% between years 2 and 3. The effectiveness of Queensland rock phosphate was about 7% that offreshly applied superphosphate in the year of application for all 3 species and for the next 2 years, its effectiveness relative to freshly applied superphosphate remained about constant for yellow serradella and approximately doubled for slender serradella and clover. For superphosphate 2.5 years after application, the amount of phosphorus extracted by the soil test compared with freshly applied superphosphate decreased by about 80%. The soil test extracted a very small proportion of the phosphorus applied as Queensland rock phosphate and the amount extracted decreased by about 50% during 2.5 years. Although the plants responded strongly to increasing levels of applied phosphorus, soil test values remained low until yields of about half the maximum yield were attained. Separate calibration curves were required for each fertiliser and species and each calibration curve was best described by 2 component linear spline functions.

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