Assessment of soil phosphorus tests for situations in Australia where reactive phosphate rock and water-soluble phosphorus fertilisers are used

1997 ◽  
Vol 37 (8) ◽  
pp. 1027 ◽  
Author(s):  
P. G. Simpson ◽  
M. J. McLaughlin ◽  
A. J. Weatherley ◽  
P. W. G. Sale ◽  
V. Hoy ◽  
...  
Keyword(s):  
Phosphate Rock ◽  
Soil Phosphorus ◽  
Subterranean Clover ◽  
Soil Test ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
P Content ◽  
Soil Test P ◽  
The Relationship ◽  
Bray 1

Summary. A selection of commonly used soil phosphorus (P) tests, which included anion and cation exchange resin membranes, were compared in a glasshouse experiment using subterranean clover, and evaluated in the field at 19 sites from the National Reactive Phosphate Rock Project in 1993 and at 6 sites in 1995. The ability of the soil P tests to predict plant response was used to evaluate the tests. In the glasshouse experiment the resin test was less effective than the Bray 1 and Colwell tests in its ability to assess the level of plant-available P from the different fertiliser treatments. Seventy-one percent of the variation in total P content of the subterranean clover shoots was explained by resin-extractable P values, whereas the Colwell procedure accounted for 81% and the Bray 1 procedure accounted for 78%. Water and CaCl2 extracts were poor predictors of P content. In the field experiments all tests evaluated performed poorly in describing the relationship between soil test P and the level of P applied and relative yield and soil test P over a wide range of soil types and environments. The Bray 1 procedure performed best but the relationship was poor.

scholarly journals Phosphorus status of pastoral soils where reactive phosphate rock fertilisers have been used

1995 ◽  
pp. 133-137
Author(s):  
K.W. Perrott ◽  
B.E. Kerr ◽  
J.H. Watkinson ◽  
J.E. Waller
Keyword(s):  
Dissolution Rate ◽  
Phosphate Rock ◽  
Linear Regression Analysis ◽  
Soil Test ◽  
Site Factors ◽  
Soil P ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Sechura Phosphate Rock ◽  
Fertiliser Application

The dissolution rate of Sechura phosphate rock (particle size 75-150 pm) was determined at 95 New Zealand sites with a range of soil and environmental properties. Rates ranged from 0 to 70% of the phosphate rock dissolved per year with an average dissolution rate of 3 1 %/year. An initial model based on stepwise linear regression analysis indicated that the rate of dissolution was negatively associated with soil pH and positively associated with rainfall and exchangeable soil magnesium. There was also an effect of soil type and drainage. The amount of residual RPR accumulated from previous fertiliser application can be determined by a new soil test. This, together with the dissolution rate estimated from the nature of the RF'R and the soil and site factors, can be used to indicate likely soil P status. Keywords: dissolution, fertiliser, phosphorus, reactive phosphate rock, soil test

The response of organic and conventionally grown wheat to superphosphate and reactive phosphate rock

1996 ◽  
Vol 36 (1) ◽  
pp. 71 ◽  
Author(s):  
PR Dann ◽  
JW Derrick ◽  
DC Dumaresq ◽  
MH Ryan
Keyword(s):  
Grain Yield ◽  
Mycorrhizal Fungi ◽  
Phosphate Rock ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Reactive Phosphate ◽  
South Wales ◽  
Large Yield ◽  
Reactive Phosphate Rock ◽  
P Content

In 1991 and 1992 wheat was sown on adjacent properties at Ardlethan in southern New South Wales to assess its response to superphosphate (SP) and reactive phosphate rock (RPR) under conventional and organic management systems. Five rates of P (0, 10, 20, 30, 40 kg/ha) were applied as SP and RPR. No response to RPR was recorded in terms of crop growth or grain yield. However, in both years and on both sites, SP significantly increased plant dry weight at tillering and anthesis, the number of tillers and spikes per plant and grain yield. Superphosphate also increased the P content of grain and the amount of P exported. SP (40 kg P/ha) increased the level of cadmium in the grain, although not beyond permitted maximum concentrations. The use of SP reduced the level of colonisation by vesicular-arbuscular mycorrhizal fungi (VAM). The data indicate that the choice of the organic farmer, not to use SP, incurs a large yield penalty.

Effect of reactive phosphate rocks and water-soluble phosphorus fertilisers on extractable phosphorus concentrations in soil

1997 ◽  
Vol 37 (8) ◽  
pp. 1009 ◽  
Author(s):  
N. K. Fleming ◽  
M. D. A. Bolland ◽  
M. A. Gilbert
Keyword(s):  
Phosphate Rock ◽  
Water Soluble ◽  
Soil Test ◽  
Phosphate Rocks ◽  
Water Soluble P ◽  
Reactive Phosphate ◽  
Soluble Phosphorus ◽  
Soil Test P ◽  
Soluble P ◽  
Pasture Yield

Summary. Soil samples were collected each year from all plots at all sites in the National Reactive Phosphate Rock Project and analysed for bicarbonate-soluble phosphorus (P) using the Colwell procedure (soil test P). The relationship between soil test P and the level of P applied was adequately described by a linear equation. The slope coefficient of this equation provides a measure of the extractability of P from soil treated with a particular fertiliser and has been termed the ‘extractability’ for that particular fertiliser at that site. Extractability values were used to estimate phosphate rock effectiveness; this was done by dividing the extractability for each phosphate rock by the extractability of the reference water-soluble P fertiliser to provide a relative soil extractability (RSE). There was a good agreement between the RSE for a phosphate rock and its substitution value for water-soluble P fertiliser, which is a measure of fertiliser effectiveness based on pasture yield. Estimates of fertiliser effectiveness, based on increases in soil test P values, also agreed with estimates based on pasture yield with respect to the ranking of different P fertilisers, and the ranking of phosphate rocks in order of their reactivity. Simple and multiple linear regression analyses were used to identify relationships between a range of soil properties and extractability values across sites, but no relationships were found.

National Reactive Phosphate Rock Project —aims, experimental approach and site characteristics

1997 ◽  
Vol 37 (8) ◽  
pp. 885 ◽  
Author(s):  
M. J. McLaughlin ◽  
N. K. Fleming ◽  
P. G. Simpson ◽  
M. D. A. Bolland ◽  
R. J. Gilkes ◽  
...  
Keyword(s):  
North Carolina ◽  
Formic Acid ◽  
Phosphate Rock ◽  
Soil Phosphorus ◽  
Triple Superphosphate ◽  
Phosphate Rocks ◽  
Agronomic Effectiveness ◽  
North Carolina Phosphate Rock ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Summary. Field-based cutting trials, which formed part of the National Reactive Phosphate Rock Project, were established across Australia in a range of environments to evaluate the agronomic effectiveness of 5 phosphate rocks, and 1 partially acidulated phosphate rock, relative to either single superphosphate or triple superphosphate. The phosphate rocks differed in reactivity. Sechura (Bayovar) and North Carolina phosphate rocks were highly reactive (>70% solubility in 2% formic acid), whilst Khouribja (Moroccan) and Hamrawein (Egypt) phosphate rock were moderately reactive. Duchess phosphate rock from Queensland was relatively unreactive (<45% solubility in 2% formic acid). Phosphate rock effectiveness was assessed by measuring pasture production over a range of phosphorus levels, and by monitoring bicarbonate-soluble phosphorus extracted from soil samples collected before the start of each growing season. Other treatments included single large applications of triple superphosphate, partially acidulated phosphate rock and North Carolina phosphate rock applied at 2 rates, and the application of monocalcium phosphate and North Carolina phosphate rock sources without sulfur to evaluate the importance of sulfur in the potential use of phosphate rock fertilisers at each site. A broad range of environments were represented over the 30 sites which were based on pastures using annual and/or perennial legumes and perennial grasses. Rainfall across the network of sites ranged from 560 to 4320 mm, soil pH (CaCl2) from 4.0 to 5.1, and Colwell-extractable phosphorus ranged from 3 to 47 µg/g before fertiliser application. Two core experiments were established at each site. The first measured the effects of phosphate rock reactivity on agronomic effectiveness, while the second measured the effects of the degree of water solubility of the phosphorus source on agronomic effectiveness. The National Reactive Phosphate Rock Project trials gave the opportunity to confirm the suitability of accepted procedures to model fertiliser response and to develop new approaches for comparing different fertiliser responses. The Project also provided the framework for subsidiary studies such as the effect of fertiliser source on soil phosphorus extractability, cadmium and fluorine concentrations in herbage, evaluation of soil phosphorus tests, and the influence of particle size on phosphate rock effectiveness. The National Reactive Phosphate Rock Project presents a valuable model for a large, Australia-wide, collaborative team approach to an important agricultural issue. The use of standard and consistent experimental methodologies at every site ensured that maximum benefit was obtained from data generated. The aims, rationale and methods used for the experiments across the network are presented and discussed.

A glasshouse evaluation of sulfur fertilizer sources for crops and pastures. III. Soluble and non-soluble sulfur and phosphorus sources for pastures

1994 ◽  
Vol 45 (7) ◽  
pp. 1525 ◽  
Author(s):  
RDB Lefroy ◽  
M Dana ◽  
GJ Blair
Keyword(s):  
Phosphate Rock ◽  
Nutrient Release ◽  
Field Capacity ◽  
Undisturbed Soil ◽  
Fertilizer Use ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
P Content ◽  
Use Efficiency ◽  
P Application

Decreasing terms of trade of animal producers and increasing awareness of environmental problems associated with fertilizer use has resulted in increased emphasis on improving fertilizer use efficiency. Elemental S and reactive phosphate rock offer two sources of fertilizers with slower nutrient release rates than gypsum or monocalcium phosphate. A randomized block experiment was conducted under glasshouse conditions. Undisturbed soil cores of an Aquic Haplustalf soil were oversown with perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens, L.), and a factorial combination of two S sources (elemental S and gypsum), two P sources (triple superphosphate, (TSP), or North Carolina reactive phosphate rock (RPR), two methods of S and P application (S mixed with granulated TSP or RPR and S coated onto TSP or granulated RPR). An unfertilized control (C) was included in order to calculate fertilizer S recovery using the 35S reverse dilution technique. Pots were either watered to field capacity (NL) or watered to 25% excess to promote leaching (L). Harvests of tops were made at 4 or 8 weekly intervals up to 96 weeks after application when the pots were destructively harvested. Yields were lower in the leached than the unleached pots between weeks 8 and 44 where TSP or G was applied. Clover yields were initially highest with G, but elemental S gave more sustained production. Yields and P content of tops were lower with RPR than TSP up to week 36. Recovery of fertilizer S was higher in the TSP than RPR treatments up to week 24. Leaching losses of S were higher from G than elemental S sources up to week 17 and were higher where TSP was the P source. Manipulation of P and S source has been shown to improve the efficiency of utilization of the applied fertilizers.

scholarly journals Direct application of reactive phosphate rock on improving maize yield in tidal swampland

2021 ◽  
Vol 648 (1) ◽  
pp. 012175
Author(s):  
A F Siregar ◽  
Husnain ◽  
I W Suastika ◽  
N P S Ratmini ◽  
I A Sipahutar ◽  
...  
Keyword(s):  
Phosphate Rock ◽  
Maize Yield ◽  
Direct Application ◽  
Reactive Phosphate ◽  
Reactive 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.

Sign in / Sign up

Export Citation Format

Share Document