ALTERNATIVE P-FERTILISERS FOR NORTHLAND SOILS

1986 ◽  
pp. 229-232
Author(s):  
P.W. Shannon
Keyword(s):  
Phosphate Rock ◽  
Growth Responses ◽  
Triple Superphosphate ◽  
Rock Phosphates ◽  
Distribution Costs ◽  
Phosphate Retention ◽  
Sechura Phosphate Rock ◽  
Local Product ◽  
Application Frequency ◽  
Chatham Rise Phosphorite

Increasing material, processing, and distribution costs have raised superphosphate prices to a point where many farms cannot support the costs of meeting maintenance phosphate requires men& Alternatives to superphosphate, particularly those that have lower processing costs and contain more P, may offer a solution to the problem provided they are agronomically as effective. Phosphate rock may indeed be such an alternative. Preliminary results from a series of five trials in Northland show that on soils of moderate P fertility, with low phosphate retention (PR) and high pH (5.9.6.0), initial pasture growth responses to rock phosphates are smaller than those from single or triple superphosphate. On one soil of higher PR and lower pH, the differences in yield between the rock-phosphates and the super. phosphates were smaller. Of the rock phosphates tested, Sechura and North Carolina (unground and ungranulated) tended to be more effective than ground and granulated Chatham Rise phosphorite. The effect on production of applying fertilisers once every three years, as opposed to annual applications is being investigated using triple superphosphate and Sechura phosphate rock. After two years, production levels appear largely unaffected by differences in application frequency. A comparison of locally-produced superphosphate with a reference standard showed that both performed similarly, indicating that the local product was of satisfactory quality.

scholarly journals Effects of frequency of maintenance phosphate fertiliser application on dry matter production from permanent pastures

1992 ◽  
pp. 55-58
Author(s):  
W.H. Risk ◽  
L.C. Smith ◽  
A.G. Sinclair ◽  
P.D. Johnstone ◽  
P.W. Shannop ◽  
...  
Keyword(s):  
Phosphate Rock ◽  
Rock Phosphate ◽  
First Year ◽  
Triple Superphosphate ◽  
Matter Production ◽  
Phosphate Fertiliser ◽  
Sechura Phosphate Rock ◽  
Application Frequency ◽  
Fertiliser Application ◽  
Annual Application

In a series of 12 field uials located throughout New Zealand annual application of phosphate(P) fertiliser was compared with ttiennial application using rates which applied the same total amount of P over 6 years. Test materials were triple supetphosphate (TSP) and Sechura phosphate rock (SPR), both of which were applied annually at rates which provided 0.75 times the calculated maintenance P requirement (0.75 M) and triennially at 2.25 M.For the 12 sites combined there was a significant response to P fertiliser each year. Application frequency had no significant effect on total DM yield over the 6 year period with either TSP or SPR. A cyclic effect with triennial applications was appsrent for both fertllisers, with approximately 2-4% higher yields in the first year and 2-4% lower yields in the third year of both 3 year cycles. These results indicate that on well developed pastures a change from annual to triennial application frequency of phosphate fertillser, with either TSP or slow release SPR, will have little effect on DM production providing the same total amount of P is applied. This gives farmers the opportunity to make some adjustment to P fertiliser application frequency according to fluctuations in availability of finance. However, these conclusions do not apply to other nutrients such as sulphur, potassium and trace elements for which annual applications may he necessary. Keywords triple superphosphate, Sechura phosphate rock, phosphate fertilisers, annual application, triennial application, application frequency, reactive phosphate reck

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

Effects of triple superphosphate and Sechura phosphate rock on clover and nitrogen content of pasture

1994 ◽  
Vol 37 (4) ◽  
pp. 569-575 ◽  
Author(s):  
J. D. Morton ◽  
M. B. O'Connor ◽  
W. H. Risk ◽  
L. Nguyen ◽  
A. G. Sinclair ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Phosphate Rock ◽  
Triple Superphosphate ◽  
Sechura Phosphate Rock

The agronomic effectiveness of reactive phosphate rocks 1. Effect of the pasture environment

1997 ◽  
Vol 37 (8) ◽  
pp. 921 ◽  
Author(s):  
P. W. G Sale ◽  
R. J. Gilkes ◽  
M. D. A. Bolland ◽  
P. G. Simpson ◽  
D. C. Lewis ◽  
...  
Keyword(s):  
North Carolina ◽  
Phosphate Rock ◽  
Surface Soil ◽  
Annual Rainfall ◽  
Triple Superphosphate ◽  
Agronomic Effectiveness ◽  
P Sorption ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Very High

Summary. The agronomic effectiveness of directly applied North Carolina reactive phosphate rock was determined for 4 years from annual dry matter responses at 26 permanent pasture sites across Australia as part of the National Reactive Phosphate Rock Project. Fertiliser comparisons were based on the substitution value of North Carolina reactive phosphate rock for triple superphosphate (the SV50). The SV50 was calculated from fitted response curves for both fertilisers at the 50% of maximum yield response level of triple superphosphate. The reactive phosphate rock was judged to be as effective as triple superphosphate in the 1st year (and every year thereafter) at 4 sites (SV50 >0.9), and was as effective by the 4th year at 5 sites. At another 9 sites the reactive phosphate rock was only moderately effective with SV50 values between 0.5 and 0.8 in the 4th year, and at the final 8 sites it performed poorly with the 4th year SV50 being less than 0.5. Pasture environments where the reactive phosphate rock was effective in the 1st year were: (i) those on sandy, humic or peaty podsols with an annual rainfall in excess of 850 mm; (ii) those on soils that experienced prolonged winter inundation and lateral surface flow; and (iii) tropical grass pastures in very high rainfall areas (>2300 mm) on the wet tropical coast on North Queensland. The highly reactive North Carolina phosphate rock became effective by the 4th year at sites in southern Australia where annual rainfall exceeded 700 mm, and where the surface soil was acidic [pH (CaCl2) <5.0] and not excessively sandy (sand fraction in the A1 horizon <67%) but had some phosphorus (P) sorption capacity. Sites that were unsuitable for reactive phosphate rock use in the medium term (up to 4 years at least) were on very high P-sorbing krasnozem soils or high P-sorbing lateritic or red earth soils supporting subterranean-clover-dominant pasture, or on lower rainfall (< 600 mm) pastures growing on soils with a sandy A1 horizon (sand component >84%). No single environmental feature adequately predicted reactive phosphate rock performance although the surface pH of the soil was most closely correlated with the year-4 SV50 (r = 0.67). Multiple linear regression analysis found that available soil P (0–10 cm) and the P sorption class of the surface soil (0–2 cm), together with annual rainfall and a measure of the surface soil"s ability to retain moisture, could explain about two-thirds of the variance in the year-4 SV50 . The results from this Project indicate that there are a number of specific pasture environments in the higher rainfall regions of Australia where North Carolina reactive phosphate rock can be considered as an effective substitute P fertiliser for improved pasture.

Comparison of phosphate rock and triple superphosphate on a phosphorus‐deficient Kenyan soil

1999 ◽  
Vol 30 (7-8) ◽  
pp. 1091-1103 ◽  
Author(s):  
Patrick K. Mutuo ◽  
Paul C. Smithson ◽  
Roland J. Buresh ◽  
Robert J. Okalebo
Keyword(s):  
Phosphate Rock ◽  
Triple Superphosphate

Residual value for wheat of phosphorus from calciphos, Duchess rock phosphate and triple superphosphate on a lateritic soil in south-western Australia

1985 ◽  
Vol 25 (1) ◽  
pp. 198 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Western Australia ◽  
Rock Phosphate ◽  
Phosphorus Content ◽  
Lateritic Soil ◽  
Triple Superphosphate ◽  
Phosphorus Fertilizer ◽  
Rock Phosphates ◽  
Christmas Island ◽  
Residual Values ◽  
North Western

The residual values of phosphorus from triple superphosphate and from three rock phosphates were compared in a 4-year field experiment with wheat, grown on a phosphorus deficient lateritic soil in south-western Australia. The three rock phosphate fertilizers were an apatitic rock phosphate originating from the Duchess deposit in north-western Queensland, and calcined (500�C) Christmas Island C-grade ore as a powder and as pellets. Five rates of each fertilizer were applied at the commencement of the experiment and their effectiveness was calculated from data on yield of dried plant tops, grain yield, and bicarbonate soluble phosphorus extracted from the soil. Triple superphosphate was the most effective phosphorus fertilizer initially, but its effectiveness decreased markedly with time. The effectiveness of the three rock phosphates was initially very low, and remained approximately constant for the duration of the experiment. The yield of dried plant tops depended upon their phosphorus content and this relationship was independent of the phosphorus fertilizer used.

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