Agronomic effectiveness of partially acidulated phosphate rock fertilisers in selected New Zealand soils

1995 ◽  
Vol 35 (3) ◽  
pp. 387 ◽  
Author(s):  
LM Condron ◽  
HJ Di ◽  
KM Goh ◽  
AS Campbell ◽  
R Harrison
Keyword(s):  
New Zealand ◽  
Phosphate Rock ◽  
Phosphorus Uptake ◽  
Partially Acidulated Phosphate Rock ◽  
Agronomic Effectiveness ◽  
Single Superphosphate ◽  
Relative Agronomic Effectiveness ◽  
Pot Trials ◽  
Highly Correlated ◽  
Manufacture Plant

The agronomic performances of some longlife superphosphate (LSP) and partially acidulated phosphate rock (PAPR) fertilizers were compared with single superphosphate in glasshouse pot trials over 9-10 months using a range of New Zealand soils. The fertilizers used differed in the type (origin) of phosphate rock (PR), the acid to rock ratio used in the production of LSP, percentage acidulation of PAPR, and incorporation of elemental sulfur into LSP. The agronomic effectiveness of the fertilizers studied was primarily influenced by the type of PR and percentage acidulation of PAPR, but not by the acid to rock ratio. Variations in the agronomic effectiveness of LSP and PAPR fertilizers made from different PRs did not reflect the relative solubilities of the original PRs. This was mainly attributed to alterations in the chemistry and consequent solubility of PR which occurred during fertilizer manufacture. Plant phosphorus uptake was highly correlated with fertilizer solubility in 2% citric and 2% formic acids. The relative agronomic effectiveness of LSP and PAPR fertilizers was not significantly related to any single soil property.

Agronomic effectiveness of partially acidulated phosphate rock as influenced by soil phosphorus-fixing capacity

1989 ◽  
Vol 120 (2) ◽  
pp. 159-164 ◽  
Author(s):  
S. H. Chien ◽  
L. L. Hammond
Keyword(s):  
Phosphate Rock ◽  
Soil Phosphorus ◽  
Partially Acidulated Phosphate Rock ◽  
Agronomic Effectiveness

Comparison of efficiency of Mussoorie partially acidulated phosphate rock and single superphosphate in a shallow Alfisol of the Indian semiarid tropics

1993 ◽  
Vol 36 (1) ◽  
pp. 29-33 ◽  
Author(s):  
D. P. Verma ◽  
S. H. Chien ◽  
C. B. Christianson ◽  
G. Pardhasardhi
Keyword(s):  
Phosphate Rock ◽  
Partially Acidulated Phosphate Rock ◽  
Single Superphosphate ◽  
Semiarid Tropics

An isotope injection technique to measure agronomic effectiveness of different phosphate sources in undisturbed soils

1995 ◽  
Vol 35 (4) ◽  
pp. 489 ◽  
Author(s):  
HJ Di ◽  
R Harrison ◽  
AS Campbell
Keyword(s):  
North Carolina ◽  
Phosphate Rock ◽  
Specific Activity ◽  
P Uptake ◽  
Injection Technique ◽  
Agronomic Effectiveness ◽  
Single Superphosphate ◽  
Simple Method ◽  
North Carolina Phosphate Rock ◽  
Undisturbed Soils

This paper describes the use of an isotope injection technique for assessing the agronomic effectiveness of phosphate sources in undisturbed soils in field and glasshouse experiments. A special injection apparatus consisting of 20 syringe needles linked to a common reservoir was used to label soil cores 150 mm in diameter and 150 mm in height, without significantly disturbing the soil structure and established perennial ryegrass (Lolium perenne) root patterns. Variations in the amount of phosphorus (P) taken up by plants from single superphosphate (applied at 30, 60, and 100 kg P/ha), from 30% acidulated North Carolina phosphate rock (60 g P/ha), and from 'as received' North Carolina phosphate rock (60 kg P/ha) were indicated by the specific activity of the plant P. Percentages of plant P derived from the fertilisers were calculated on the basis of the specific activity of the fertilised treatments and the controls. The technique provides a simple method of comparing the agronomic effectiveness of phosphate sources in undisturbed soils and, unlike total dry matter yield and P uptake, is relatively unaffected by environmental factors.

scholarly journals The long-term effectiveness of reactive phosphate rock as a phosphate fertiliser for New Zealand pastures

1990 ◽  
pp. 101-104 ◽  
Author(s):  
A.G. Sinclair ◽  
C.B. Dyson ◽  
P.W. Shannon
Keyword(s):  
New Zealand ◽  
Phosphate Rock ◽  
Field Trials ◽  
Superior Performance ◽  
Single Superphosphate ◽  
Reactive Phosphate ◽  
Application Rates ◽  
Phosphate Retention ◽  
Reactive Phosphate Rock ◽  
Sechura Phosphate Rock

Sechura reactive phosphate rock (SPR) and triple superphosphate (TSP) have been compared as phosphate fertihsers for pastures in a series of 19 field trials dispersed throughout New Zealand, each continuing for 3-6 years. Both fertilisers were applied annuaIly at 4 rates. In the first 2 years SPR was much less effective at increasing dry matter yields than TSP, but its performance improved markedly with time. In year 6 SPR outyielded TSP at alI application rates for all sites combined. The relative performance of SPR and TSP differed markedly at different sites. Very high soil phosphate retention and a combination of low moisture and high pH appeared to be unfavourable for SPR performance. In most sites SPR was equal or superior to TSP by year 6. SPR substantially raised molybdenum concentration in clovers, and this may have contributed to its superior performance at some sites. As TSP and single superphosphate were equally effective, the good performauce of SPR and the relative cheapness of reactive phosphate rocks suggest an important role for the latter on New Zealand pastures. Keywords Sechura phosphate rock, reactive phosphate rock, RPR, superphosphates, phosphate fertilisers

Developments in some aspects of reactive phosphate rock research and use in New Zealand

1997 ◽  
Vol 37 (8) ◽  
pp. 861 ◽  
Author(s):  
N. S. Bolan ◽  
M. J. Hedley
Keyword(s):  
New Zealand ◽  
Phosphate Rock ◽  
Direct Application ◽  
Soil Test ◽  
Phosphate Rocks ◽  
Agronomic Effectiveness ◽  
Olsen P ◽  
The North ◽  
Soluble P ◽  
P Sources

Summary. There has been over 50 years of use and research into the agronomic effectiveness of reactive phosphate rocks (RPR) directly applied to New Zealand pastures. In recent years RPR-carrying fertilisers made up about 16% of phosphatic fertiliser sales in the North Island of New Zealand. Most is applied, as maintenance fertiliser, to hill country sheep and beef farms. Use has been recommended on soils with pH <6 and in annual rainfall regimes >800 mm. This is based on the poor performance of Sechura phosphate rock in summer dry areas receiving <750 mm of rainfall annually. Phosphate rocks that have more than 30% of their total phosphate soluble in 2% citric acid have been classed as ‘reactive’ and suitable for direct application. More recent research indicates that extraction with 2% formic acid, or a dissolution test performed in a simulated soil solution at a fixed pH, will provide improved measures of RPR quality. Field trials, undertaken by the New Zealand Ministry of Agriculture and Fisheries [MAF; now AgResearch Crown Research Institute (CRI)] and others, to evaluate the relative agronomic effectiveness of RPR versus soluble P fertilisers in adequate to marginally P-deficient soils have proven to be a painstaking task. Long periods (3–6 years) of fertiliser withdrawal were required for pasture growth on some soils to become significantly responsive to applied P. Only then did differences between P sources become significant. This problem has encouraged efforts to relate measurements of the extent of RPR dissolution in soils to their agronomic effectiveness. Three main modelling approaches have been used to achieve this objective: Kirk and Nye (1986a, 1986b, 1986c); Sinclair et al. (1993a); and Watkinson (1994b). These models are reviewed and their explanation of RPR dissolution in mowing trials tested. Components of each model have then been combined to produce models to predict the agronomic effectiveness of RPR. The development of P tests for soils receiving RPR-containing fertilisers is reviewed. Separate Olsen P test–yield response calibration curves are required for soils fertilised with soluble P fertilisers and soils fertilised with sparingly soluble P sources or soluble P in the presence of heavy lime applications. Whereas alkaline P tests such as Olsen or Colwell underestimate the amount of plant-available P in these soils, acid P tests such as Bray 1 are likely to overestimate the available P. Tests involving cation and anion exchange resin membranes appear to be more appropriate for soils with unknown histories of soluble P and RPR use and may permit the use of single calibration curves. Trends observed in Olsen P soil test values, from farms on the North Island of New Zealand that have a history (3–15 years) of RPR use are presented. A predictive dissolution model is used to explain these trends but it is evident that spatial and temporal variation in soil test results on farmers’ paddocks will be a major constraint to the precision to which this or similar models may be used. The model, however, may provide the basis for sound advice on the strategic use of RPR for direct application to New Zealand pasture soils. It may prove useful in explaining the variation in RPR effectiveness in a wider range of climates and soils.

scholarly journals Effectiveness of phosphate fertilizers of diffrent water solubilities in relation to soil phophorus adsorption

2006 ◽  
Vol 63 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
Jack Fernando Santos Quispe ◽  
Eros Artur Bohac Francisco ◽  
Graziela Braga
Keyword(s):  
Water Solubility ◽  
P Uptake ◽  
Low Grade ◽  
Phosphate Fertilizers ◽  
Agronomic Effectiveness ◽  
Single Superphosphate ◽  
Greenhouse Study ◽  
Relative Agronomic Effectiveness ◽  
Alternative Sources ◽  
P Sources

Phosphate fertilizers should match soil attributes to enhance agronomic effectiveness and recovery by plants. The purpose of this study was to test the agronomic effectiveness of P sources varying in water solubility on two soils differing widely in P adsorption capacity (PAC). Soils selected for the study were Oxisols with very low available P and presenting low and high PAC (Ox-LPAC and Ox-HPAC, respectively). Both were limed to pH 5.4 in a greenhouse study conducted utilizing corn as the test crop. Treatments consisted of the two soils interacting with five P sources (monocalcium phosphate - MCP, low-grade single superphosphate - LG-SSP, multimagnesium phosphate - MMP, Arad phosphate rock - PR and a P impurity in triple superphosphate - H14), and four rates of P (12.5, 25.0, 50.0 and 100.0 mg kg-1). A control with no P was added for each soil. The treatments were arranged as blocks with three replicates. Plants were harvested 45 d after germination. Dry-matter yield and P uptake were measured and the relative agronomic effectiveness (RAE) compared with MCP as the standard. When applied in low rates of P (12.5 and 25.0 mg kg-1) the RAE of the alternative sources was higher in the soil with high PAC (45, 66, 39 and 65% in the Ox-HPAC for the LG-SSP, MMP, PR and H14, respectively, as opposed to 24, 40, 14 and 47% in the Ox-LPAC). Results suggest that sources of P with low water solubility can be agronomically more effective in soils with high PAC.

scholarly journals Summary of eleven long-term field trials with 'Longlife' phosphatic fertiliser

1992 ◽  
pp. 35-40
Author(s):  
S.F. Ledgard ◽  
B.S. Thorrold ◽  
A.G. Sinclair ◽  
S.S.S. Rajan ◽  
D.C. Edmeades
Keyword(s):  
New Zealand ◽  
Phosphate Rock ◽  
Field Trials ◽  
Triple Superphosphate ◽  
Single Superphosphate ◽  
The North ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Term Field

Longlife' phosphatic fertiliser is manufactured in New Zealand by mixing reactive phosphate rock (RPR) with single superphosphate (SSP) when the SSP is at an ex-den stage. Commercially produced Longlife (70:30 SSP:RPR) was evaluated in 6 field mowing trials in the North Island over 3 or4 years. Also, a 5050 (SSP:RPR) Longlife-type product was examined in 5 field trials throughout New Zealand over 5 or 6 years. Longlife was compared against SSP and/or triple superphosphate (TSP) in all trials, and RPR treatments were included in 7 trials. In all trials with commercially produced Longlife, the pasture response to Longlife tended to be less than that to SSP or TSP in the first 2 years and was significantly different (P 6.0 and/or rainfall ~800 mm/year). Keywords field trials, Longlife, phosphate, reactive phosphate rock, superphosphate

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