Pasture environments in Australia where reactive phosphate rock will be an effective phosphate fertiliser

1997 ◽  
Vol 37 (8) ◽  
pp. 1051 ◽  
Author(s):  
P. W. G. Sale ◽  
A. Brown ◽  
G. Maclaren ◽  
P. K. Derbyshire ◽  
S. M. Veitch
Keyword(s):  
Soil Properties ◽  
Phosphate Rock ◽  
Water Soluble ◽  
Annual Rainfall ◽  
High Rainfall ◽  
Water Soluble P ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Suitability Maps ◽  
Soluble P

Summary. Maps are constructed using Geographic Information Systems (GIS) computer technology to identify privately held land in the high rainfall zones of temperate and tropical Australia where highly reactive phosphate rocks (RPRs) are likely to be effective phosphorus (P) fertilisers for permanent pasture. Australia-wide RPR suitability maps were based on annual rainfall, soil pH and the P sorption capacity of the soil. The digitised soil map from the Atlas of Australian Soils and the soil profile acidity map derived from the Atlas, were used to identify land areas with suitable soil properties. The coarse scale of the Atlas, which has only the 1 dominant soil for each 100 ha minimum landscape unit, limits the precision in identifying specific land types. Reactive phosphate rock suitability maps for pasture land in Victoria were also developed using smaller land units and state-wide digitised soil maps for surface pH and surface texture. The GIS maps indicated that there are about 26.5 × 106 ha of land in the high rainfall pastoral zone of Australia that have sufficient annual rainfall and appropriate soil properties for RPR to become effective by the 4th year after changing from annual water-soluble P fertiliser to RPR fertiliser applications. Additional land with a lower rainfall might also be suitable if the soil surface is not excessively sandy. The area of high rainfall pasture land where RPR is likely to be as effective as water-soluble P fertiliser in the first year of application is around 3 × 106 ha. The major portion of this land is in North Queensland, with smaller areas in southern Victoria, in far north-west Tasmania and in the far south-west of Western Australia. More detailed GIS maps for Victoria indicate that RPRs would become as effective as water-soluble P fertiliser by the 4th year on more than 70% of private land where annual rainfall exceeds 700 mm.

An appraisal of the National Reactive Phosphate Rock Project

1997 ◽  
Vol 37 (8) ◽  
pp. 1085
Author(s):  
D. J. Reuter
Keyword(s):  
Expert System ◽  
Phosphate Rock ◽  
Field Experiments ◽  
Water Soluble ◽  
Annual Rainfall ◽  
Yield Response ◽  
Triple Superphosphate ◽  
Reactive Phosphate ◽  
Independent Field ◽  
Reactive Phosphate Rock

Summary. An expert system has been developed, using the results from the National Reactive Phosphate Rock Project, to determine whether reactive phosphate rock is likely to be an effective substitute for water-soluble superphosphate fertiliser for a given pasture environment. The evaluation is made from site information [annual rainfall, pasture composition and the likelihood of phosphorus (P) leaching], and soil information (pH, Colwell P, soil colour and field texture). The expert system can determine the effectiveness of both highly reactive and moderately reactive phosphate rocks. Observed substitution values of triple superphosphate for the highly reactive North Carolina phosphate rock (ratio of the respective P levels required to produce 50% of the maximum observed yield response to triple superphosphate) were closely related to values predicted by the expert system (r = 0.92); the relationship between observed and predicted substitution values of single superphosphate for the moderately reactive Hemrawein phosphate rock was also close (r= 0.86). The expert system gives one of 4 different recommendations for reactive phosphate rock based on the magnitude of the predicted substitution values. These are ‘immediately effective’, ‘effective in the medium term’, ‘marginally effective’, and ‘not effective’. The system was validated using the results from independent field experiments that provided measures of the effectiveness of reactive phosphate rock at different pasture sites.

Building an expert system to advise on the use of reactive phosphate rock on Australian pastures

1997 ◽  
Vol 37 (8) ◽  
pp. 1077 ◽  
Author(s):  
P. Gillard ◽  
P. W. G. Sale ◽  
S. B. Tennakoon
Keyword(s):  
Expert System ◽  
Phosphate Rock ◽  
Field Experiments ◽  
Water Soluble ◽  
Annual Rainfall ◽  
Yield Response ◽  
Triple Superphosphate ◽  
Reactive Phosphate ◽  
Independent Field ◽  
Reactive Phosphate Rock

Summary. An expert system has been developed, using the results from the National Reactive Phosphate Rock Project, to determine whether reactive phosphate rock is likely to be an effective substitute for water-soluble superphosphate fertiliser for a given pasture environment. The evaluation is made from site information [annual rainfall, pasture composition and the likelihood of phosphorus (P) leaching], and soil information (pH, Colwell P, soil colour and field texture). The expert system can determine the effectiveness of both highly reactive and moderately reactive phosphate rocks. Observed substitution values of triple superphosphate for the highly reactive North Carolina phosphate rock (ratio of the respective P levels required to produce 50% of the maximum observed yield response to triple superphosphate) were closely related to values predicted by the expert system (r = 0.92); the relationship between observed and predicted substitution values of single superphosphate for the moderately reactive Hemrawein phosphate rock was also close (r= 0.86). The expert system gives one of 4 different recommendations for reactive phosphate rock based on the magnitude of the predicted substitution values. These are ‘immediately effective’, ‘effective in the medium term’, ‘marginally effective’, and ‘not effective’. The system was validated using the results from independent field experiments that provided measures of the effectiveness of reactive phosphate rock at different pasture sites.

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.

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.

scholarly journals ASSESSMENT OF PHOSPHORUS AVAILABILITY FROM UNREACTIVE TOGO PHOSPHATE ROCK BY LEGUME AND CEREAL CROPS IN TWO GHANAIAN SOILS

2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Alex Boateng ◽  
Prof. Emmanuel Owusu- Bennoah
Keyword(s):  
Phosphate Rock ◽  
Dry Matter ◽  
P Uptake ◽  
Phosphorus Availability ◽  
Direct Application ◽  
Water Soluble ◽  
Cereal Crops ◽  
Dry Matter Yield ◽  
Water Soluble P ◽  
Soluble P

Purpose: In recent years, phosphate rock (PR) for direct application has been tested in tropical acid soils as a potential alternative to conventional water-soluble P fertilizers like Single Superphosphate (SSP) and Triple Superphosphate (TSP). However, direct application of PR with low reactivity does not always give satisfactory results. Legume and cereal crops represent a strategy that can be used to solubilize P from some of these unreactive PRs. The objective of this study was to assess the availability of P from unreactive Togo Phosphate Rock (TPR) relative to TSP by six (6) crop species in two Ghanaian soils. Methodology:  The study was conducted in the greenhouse of the Crop Science Department, University of Ghana. Three P rates, 0mg, 50mg and 100mg P of TPR and TSP were applied to a kilogram of soil per pot in the two soil series. Randomized Complete Block Design was used to do the analyses. Results/Findings: Application of TSP resulted in higher dry matter and P uptake irrespective of the soil type. Among the legumes, cowpea gave the highest dry matter yield. Fairly, a similar trend was obtained with the application of TPR. Among the cereals, the average P uptake by sorghum from TPR was the highest, followed by maize and millet in the Nzema soil. In the Adenta series, P uptake by maize was the highest, followed by sorghum and millet. Phosphorus (P) uptake by the cereals from TPR was generally better in the Adenta than the Nzema soil. Unique contribution to theories, practice and policy: Results show increasing the rate of TPR to 100mg P/pot resulted in an increase in dry matter yield and P uptake in both soils, but was inferior to 100mg P/pot TSP application. Consequently, the rate of application of TPR should always be high if farmers want the best from their investments. Again, the low relative agronomic effectiveness of TPR for all the crops, proved the low reactivity of the material and its subsequent low performance compared with the water-soluble P. The low reactivity and the high molar mass of PO43-/CO32- of the TPR will always make it difficult for P to be made available from the TPR despite the acidity of the soil, the high density of the crops and the ability of the tested crops to exude organic acids, which facilitate phosphorus availability from TPR, therefore making TPR unsuitable for direct application.

scholarly journals Ratio and rate effects of 32P-triple superphosphate and phosphate rock mixtures on corn growth

2009 ◽  
Vol 66 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Vinícius Ide Franzini ◽  
Takashi Muraoka ◽  
Fernanda Latanze Mendes
Keyword(s):  
Phosphate Rock ◽  
Water Soluble ◽  
P Availability ◽  
Triple Superphosphate ◽  
Water Soluble P ◽  
P Rate ◽  
P Utilization ◽  
P Recovery ◽  
Soluble P ◽  
Corn Plants

The availability of phosphorus (P) from " Patos de Minas" phosphate rock (PR) can be improved if it is applied mixed with a water-soluble P source. The objective of this study was to evaluate 32P as a tracer to quantify the effect of the ratio of mixtures of triple superphosphate (TSP) with PR and the rates of application on P availability from PR. Two experiments were conducted in a greenhouse utilizing corn (Zea mays L.) plants as test crop. In the first experiment, the P sources were applied at the rate of 90 mg P kg-1 soil either separately or as compacted mixtures in several TSP:PR ratios (100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 calculated on the basis of the total P content). In the second experiment, the TSP was applied alone or as 50:50 compacted mixtures with PR applied at four P rates (15, 30, 60 and 90 mg P kg-1) while the sole PR treatment was applied at the 90 mg kg-1 P rate . The mixture of PR with TSP improved the P recovery from PR in the corn plant and this effect increased proportionally to the TSP amounts in the mixture. When compared with the plant P recovery from TSP (10.52%), PR-P recovery (2.57%) was much lower even when mixed together in the ratio of 80% TSP: 20% PR. There was no difference in PR-P utilization by the corn plants with increasing P rates in the mixture (1:1 proportion). Therefore, PR-P availability is affected by the proportions of the mixtures with water soluble P, but not by P rates.

Increasing rock phosphate efficient use through soil amendment with waste biomasses

2021 ◽  
Author(s):  
Lea Piscitelli ◽  
Zineb Bennani ◽  
Donato Mondelli
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Amendment ◽  
Phosphate Rock ◽  
Rock Phosphate ◽  
Water Soluble ◽  
Water Soluble P ◽  
Pot Trial ◽  
Soluble P ◽  
Mill Waste

&lt;p&gt;Loss of soil organic carbon content can limit the soil's ability to provide goods and services. In agricultural soil this may lead to lower yields and affect food security. In this context, the proper use of waste biomasses as soil amendment is a valuable alternative to disposal with numerous benefits to soil fertility with a direct effect on soil organic matter content. Moreover, beside this direct effect waste biomasses can have a beneficial result on nutrients.&lt;/p&gt;&lt;p&gt;In modern agriculture the use of rock phosphate as fertilizer is crucial but abused. Although this non-renewable resource reserves may be depleted in 50-100 years, many farmers still use overabundant amount of rock phosphate-based fertilizers with an additional environmental burden. From a chemical point of view the efficient use of rock phosphate can be increased by some agricultural practices and amending soil with waste biomasses is one of them.&lt;/p&gt;&lt;p&gt;Here we propose the use of 3 different waste biomasses on phosphate rock dissolution and subsequent phosphorus availability. The 3 waste biomasses, citrus pomace, olive oil mill waste and barley spent grains, were selected mainly for their potential direct or indirect effect on pH. This experiment was composed by two steps a bench and a pot trial. In the bench trial the waste biomasses and phosphate rock were mixed and transferred in litterbags. In these litterbags pH, water soluble P, matter loss and total P were destructively analyzed each 10 days for a month. In the pot trial the same combination of waste biomasses and phosphate rock were tested in a soil plant system; some agronomic parameters were measured on rocket salad and pH, soil-P availability, acid phosphatase activity were analyzed in soil.&lt;/p&gt;&lt;p&gt;In bench trial, barley spent grain plus phosphate rock shows the highest water soluble P, citrus pomace plus phosphate rock showed a significant correlation between water soluble P and pH while olive oil mill waste plus phosphate rock has high correlation between water soluble P and matter loss. These two treatments were also the best performing in the pot trial in terms of rocket salad yield and soil available P. Even though the investigation was conducted on a short lived experiment, some results are encouraging and displays good agronomic performances of waste biomasses plus phosphate rock. Nevertheless, next studies should consider other waste biomasses within longer experiments. Additionally, scaling up the experiment to a field application can provide more thorough information about the effects on soil organic carbon and P dynamics.&lt;/p&gt;

The use of substitution values for characterising fertiliser performance

1997 ◽  
Vol 37 (8) ◽  
pp. 913
Author(s):  
D. A. Ratkowsky ◽  
S. B. Tennakoon ◽  
P. W. G. Sale ◽  
P. G. Simpson
Keyword(s):  
Phosphate Rock ◽  
Statistical Tests ◽  
Effective Means ◽  
Field Trials ◽  
Water Soluble ◽  
Soluble Phosphate ◽  
Phosphate Rocks ◽  
High Performing ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Summary. The substitution value, or horizontal comparison between a fertiliser and some high-performing reference fertiliser, is shown to be a powerful and effective means of ranking the performance of various reactive phosphate rock fertilisers relative to a water-soluble phosphate such as a superphosphate. To take account of the variability due to random error in fertiliser field trials, the use of a standardised score, one measuring the relative departure of the substitution value from that expected for the standard fertiliser, is shown to be a suitable statistic for general use. Cluster analyses using these z-scores as input data can lead to appropriate decision making such as, for example, grouping experimental sites into: (i) those which perform as well as water-soluble phosphate, (ii) those which are somewhat worse than water-soluble phosphate, and (iii) those which are much worse than water-soluble phosphate. Substitution values obtained for different reactive phosphate rocks were compared both within and between sites, using appropriate statistical tests of significance. This approach assisted in ranking the performance of the 5 reactive phosphate rocks and the partially acidulated phosphate rock studied in the National Reactive Phosphate Rock Project, and helped predict which ones are likely to be suitable for use in differing environments.

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
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