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

Soil sulfur status, sulfur fertiliser responses and rainfall sulfur accessions at trial sites in the National Reactive Phosphate Rock Project

1997 ◽  
Vol 37 (8) ◽  
pp. 995 ◽  
Author(s):  
G. Anderson ◽  
G. J. Blair ◽  
M. Crestani ◽  
D. Lewis
Keyword(s):  
Phosphate Rock ◽  
Direct Application ◽  
First Year ◽  
Soil Profiles ◽  
North West ◽  
The North ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Chemical Extractants ◽  
Soil Sulfur

Summary. The sulfur (S) status of the National Reactive Phosphate Rock Project trial sites was determined using 2 chemical extractants KCl-40 (0.25 mol KCl/L heated to 40°C) and MCP (0.01 mol mono-calcium phosphate/L). There were marked differences between sites in KCl-40- extractable S down the soil profile. Soil profiles were classified into 4 groups according to the shape of the extractable S profile. KCl-40 was better able to distinguish between responsive (significant at P = 0.10 only) and unresponsive sites than MCP. Mean S accession in rainfall over the 3 years ranged from 0.40 kg/ha . year at Jericho (site T17) in the centre of Tasmania to 20.33 kg/ha . year at Smithton (site T16) on the north-west coast of Tasmania. The proportion of S-responsive sites increased from 26% in the first year to 43, 42 and 48% in years 2, 3 and 4 respectively. Such a large proportion of S-responsive sites limits the use of direct application of reactive phosphate rock fertiliser.

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.

Chemical effects in commercial and laboratory mixtures of ?reactive? phosphate rock and acidulated fertilisers

1992 ◽  
Vol 31 (1) ◽  
pp. 111-118 ◽  
Author(s):  
A. C. Braithwaite ◽  
A. C. Eaton ◽  
P. S. Groom
Keyword(s):  
Phosphate Rock ◽  
Chemical Effects ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Partially acidulated reactive phosphate rock (PAPR) fertilizer and its reactions in soil

1991 ◽  
Vol 28 (3) ◽  
pp. 295-304 ◽  
Author(s):  
D. C. Golden ◽  
R. B. Stewart ◽  
R. W. Tillman ◽  
R. E. White
Keyword(s):  
Phosphate Rock ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

scholarly journals WHITE CLOVER CULTIVAR RESPONSES TO PHOSPHATE FERTILISERS OF DIFFERING SOLUBILITY

1988 ◽  
pp. 151-156
Author(s):  
A.D. Mackay ◽  
J.R. Caradus
Keyword(s):  
White Clover ◽  
Phosphate Rock ◽  
Dry Matter ◽  
Water Solubility ◽  
Partially Acidulated Phosphate Rock ◽  
Leaf Number ◽  
Monocalcium Phosphate ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Stolon Length

A glasshouse study investigated the dry matter response of Grasslands Kopu and Grasslands Tahora white clover, cultivars of differing origins and morphologies, to three phosphate fertilizers, monocalcium phosphate (MCP), partially acidulated phosphate rock (PAPR) and a reactive phosphate rock, North Carolina phosphate rock (NCPR), of differing water solubility. Kopu responded more rapldly and reached Its maximum dry matter yield at a lower phosphorus (P) level than Tahora when MCP and NCPR were the P fertilizers. With PAPR as the P fertilizer, their response was similar. The shoot dry matter response by Kopu to all three P sources was reflected more in leaf weight and size than leaf number or stolon length. In contrast Tahora responded to added P by increasing leaf number and stolon length to a much greater extent than Kopu. Keywords: Trifolium repens, monocalcium phosphate, partially acidulated phosphate rock, reactive phosphate rock.

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