Evaluation of soil phosphate status where phosphate rock based fertilizers have been used

1993 ◽  
Vol 35 (1-2) ◽  
pp. 67-82 ◽  
Author(s):  
K. W. Perrott ◽  
S. Saggar ◽  
R. G. Menon
Keyword(s):  
Phosphate Rock ◽  
Soil Phosphate

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.

Uranium in phosphate rock

1975 ◽  
Author(s):  
James Bachelder Cathcart
Keyword(s):  
Phosphate Rock

A summary of phosphate-rock resources of the United States; an analysis of past estimates

1981 ◽  
Author(s):  
James Bachelder Cathcart ◽  
Richard Porter Sheldon ◽  
Robert A. Gulbrandsen
Keyword(s):  
United States ◽  
Phosphate Rock ◽  
The United States

NIROSTA 4465

Alloy Digest ◽  
2000 ◽  
Vol 49 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Intergranular Corrosion ◽  
Phosphate Rock ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Low Carbon ◽  
High Chromium ◽  
Temperature Performance

Abstract Nirosta 4465 is a low-carbon, high-chromium alloy with nickel and molybdenum. It has good corrosion and intergranular corrosion resistance. The alloy is used for processing phosphate rock. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-797. Producer or source: ThyssenKrupp Nirosta.

Kinetics of Phosphate Rock Dissolution in Acidic Soil Amended with Liming Materials and Cellulose

1996 ◽  
Vol 60 (6) ◽  
pp. 1589-1595 ◽  
Author(s):  
Z. L. He ◽  
V. C. Baligar ◽  
K. D. Ritchey ◽  
D. C. Martens ◽  
W. D. Kemper
Keyword(s):  
Phosphate Rock ◽  
Acidic Soil ◽  
Phosphate Rock Dissolution ◽  
Kinetics Of

Overview of Current Phosphoric Acid Production Processes and a New Idea of Kiln Method

2020 ◽  
Vol 17 ◽  
Author(s):  
Guangya Zheng ◽  
Jupei Xia ◽  
Zhengjie Chen
Keyword(s):  
Phosphoric Acid ◽  
Acid Production ◽  
Phosphate Rock ◽  
Low Grade ◽  
Production Methods ◽  
Production Processes ◽  
Major Equipment ◽  
Development Prospects ◽  
Great Competitiveness

: China primarily contains medium and low-grade phosphorus ores that are used to produce phosphoric acid. Here, we provide an overview of phosphoric acid production processes, including wet, thermal, and kiln methods, as well as the fundamental principles, major equipment, and technological aspects of each process. Progress in the kiln method using lowgrade phosphate rock is described, which involves the KPA and CDK processes. The literature shows that the addition of admixtures adds great competitiveness to kiln phosphate production methods and has considerable development prospects.

Phosphorus equivalence ofaspergillus nigerphytase for growing pigs

1995 ◽  
Vol 1995 ◽  
pp. 40-40
Author(s):  
Naheeda Khan ◽  
D.J.A. Cole
Keyword(s):  
Total Phosphorus ◽  
Current Literature ◽  
Livestock Production ◽  
Growing Pigs ◽  
Environmental Constraints ◽  
Experimental Conditions ◽  
Production Sector ◽  
Soil Phosphate ◽  
Phosphorus Requirements ◽  
Inorganic Phosphates

Inconsistencies in the estimated phosphorus requirements of growing pigs have come to light in recent years due to environmental constraints being imposed on the livestock production sector. Values of a net requirement estimated by the ARC (1981) extend from 4.6 g/day for 25kg liveweight to 5.2 g/day for 45kg pigs, but current literature suggesting that the actual requirement may be lower (eg Jongbloed and Everts, 1991) calls for a revision of previous recommendations.Around two thirds of the total phosphorus in cereals exists in the form of insoluble phytates which must be degraded before the phosphorus can be absorbed in the intestine. Under experimental conditions, the use of phytase in pig diets has demonstrated consistent improvements in phosphorus digestibility. The enzyme hydrolyses phytate by stepwise removal of orthophosphates, which become available for absorption in the gut. Although quantification of phytase/phosphorus substitution is as yet undetermined, digestibility results so far indicate that if used correctly the enzyme could largely replace inorganic phosphates, particularly in regions where soil phosphate levels are of concern.

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