Results 251 to 260 of about 161,196 (302)

Phosphate rock and phosphate rock/sulphur granules as phosphate fertilizers and their dissolution in soil

Fertilizer Research, 1987
A field trial was conducted for 3 years to evaluate phosphate rocks and phosphate rock/sulphur granules as fertilizers for permanent pastures. Two reactive phosphate rocks, North Carolina (USA) and Chatham Rise (New Zealand), and an unreactive Florida (USA) were used.
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Phosphate supplying power of rock phosphates in an oxisol

Plant and Soil, 1980
The P-supplying power of triple superphosphate, three apatitic rock phospates and a calcined aluminum rock phosphate were tested by measuring the quantities of fertilizer P recovered in soybean and in four chemical extractants, after 3-day and 75-day periods of contact between soil and fertilizer.
van Raij, B., van Diest, A.
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Phosphate rocks and partially-acidulated phosphate rocks as controlled release P fertilizers

Fertilizer Research, 1993
Properties of phosphate rocks (PRs) and partially acidulated phosphate rocks (PAPRs) which affect the pattern of P dissolution and thus the potential for manipulating the rate of P release are reviewed. The effects of soil and plant properties are also considered.
J. Hagin, R. Harrison
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Mussoorrie rock phosphate-pyrite mixture as phosphate fertilizer

Fertilizer Research, 1996
Mussoorrie rock phosphate (MRP), MRP + pyrite (25% by weight), diammonium phosphate (DAP), ammonium polyphosphate (APP) and nitrophosphate (NP) were compared in a field experiment as fertilizers for wheat. At 20 kg P ha−1, MRP was only 6 per cent as effective as DAP. However, when it was mixed with pyrite, the efficiency of MRP increased to 64 per cent
S. N. Sharma, R. Prasad
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The agronomic effectiveness of reactive phosphate rocks 2. Effect of phosphate rock reactivity

Australian Journal of Experimental Agriculture, 1997
Summary. The chemical reactivity of apatite phosphate rock (PR) from Sechura (Bayovar), North Carolina, Egypt (Hamrawein), Morocco (Khouribja) and Queensland (Duchess), was estimated using the following methods (indices): percentage of the phosphorus (P) present in the PR that is soluble in one extraction with 2% citric acid and 2% formic acid, and ...
R. J. Gilkes, M. D. A. Bolland
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Phosphate rocks and phosphate rock/sulphur granules as fertilisers for hill country pasture

New Zealand Journal of Experimental Agriculture, 1986
Abstract Reactive phosphate rocks (PR) from North Carolina and Peru (Sechura), applied either as granules or after co-granulation with elemental sulphur (PR/S), were evaluated as phosphate fertilisers on a north-facing slope of a hill country pasture. Single superphosphate was used as the standard fertiliser. The fertilisers were applied annually for 3
S.S.S. Rajan, A.G. Gillingham
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Phosphate Rocks and Nuclear Proliferation

Science & Global Security, 2017
Phosphate rocks are predominantly mined for fertilizer production. However, they also contain considerable amounts of accompanying natural uranium that can exceed concentrations found at commercial...
Nils Haneklaus, Anastasiya Bayok, Vitaly Fedchenko   +2 more
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Uranium in phosphate rock

Open-File Report, 1975
Al Introduction 1 Guano and guano-derived deposits 1 Igneous apatite deposits 2 Marine phosphorite 2 Secondary deposits 3 Page Other deposits A4 Lake beds 4 Offshore deposits 4 Phosphate resources 5 Selected references ...
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Rock Phosphates in Agriculture

Experimental Agriculture, 1991
SUMMARYThe principles that control effectiveness of rock phosphates as fertilizer are now fairly well understood so that the potential effect of a material can be predicted with some confidence from laboratory analysis of the raw material. Soil characteristics, especially acidity, and calcium and phosphate status, are important: if these are not ...
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Leaching effect on phosphate rock

Journal of Radioanalytical and Nuclear Chemistry Letters, 1996
The uranium content in ground phosphate rock was leached out with alkaline solution, however, a poor yield was obtained. XRD, TGA and α-spectrometric analyses in the solid fraction showed that francolite is the main mineral in which uranium is present in different oxidation states (+4 and +6).
E. T. Romero-Guzmán, E. Ordoñez-Regil, V. H. Lara Corona   +2 more
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