Determination Of Available Phosphorus Research Articles

Evaluation of Soil Tests for Phosphorus Availability

A number of methods are in use to determine the available phosphorus in soils. Some of these methods have given satisfactory results in certain soils, but none has been found to be applicable under all soil conditions. Hence in this study an attempt is made to compare a number of soil tests for available phosphorus with the phosphorus uptake by ragi seed- lings in a Neubauer experiment to determine which method is most suitable for each soil type or a group of soil types in the matter of predicting yield or uptake of phosphorus. Simplicity, rapidity and dependability have been taken as the chief considerations in the choice of methods for determination of available phosphorus.

Rapid Ammonium Citrate Extraction Method for Determination of Available Phosphorus

Abstract Available phosphorus has been determined in fertilizers by a quick extraction method useful for screening or quality control purposes. Samples were extracted in a Gooch crucible with a jet of 65 °C neutral ammonium citrate in 10—20 mill. A single direct determination of available phosphorus was made by the alkalimetric quimociac method, modified for speed and for use in high citrate concentrations. The results compare favorably in accviracy to the gravimetric quimociac results reported on 20 Magruder check fertilizer samples

Improved Techniques for Determining Available Phosphorus in Fertilizers

Abstract The determination of available phosphorus in fertilizers by the direct available gravimetric quinoline molybdate method has been made 100% faster and considerably easier by use of a multiple-unit pipetter and other glassware similarly bound together in multiple units. Each piece of apparatus and its operation are described.

Spectrophotometric Method for the Direct Determination of Available Phosphorus in Fertilizers: Use of Dry Ashing to Destroy Citrate

Abstract A simple, rapid spectrophotometry method has been developed for direct determination of available phosphorus in fertilizers. Citrate and other organic materials are destroyed by dry ashing. The combined water and citrate extracts are diluted, a 5 ml aliquot is pipetted into a 25 ml Erlenmeyer flask, and 2 ml of ashing reagent (dilute HNO3, sucrose, and MgO) is added. During evaporation to dryness on a hot plate, nonorthophosphates are hydrolyzed to orthophosphates which react with Mg to form heat-stable compounds. During the subsequent ashing, phosphorus remains in the ortho form. Due to sucrose, the dry residue has a very porous structure and can be converted to a white ash in about 30 minutes in a pre-heated 550°C muffle. Color is developed with vanadomolybdic acid reagent. Absorbance is read on a spectrophotometer at 400 mμ.

Quinoline Molybdate Method for the Determination of Water-Soluble and Available Phosphorus in Fertilizers

Abstract Addition of a separate acid hydrolysis step in the determination of watersoluble phosphorus was found necessary in the official volumetric method but not in the quinoline molybdate method. By carefully controlling the phosphorus and ammonium citrate concentrations in the direct determination of available phosphorus, phosphorus can be completely precipitated as quinoline phosphomolybdate. The nitration of the ammonium citrate digestate in preparing the combined water-soluble and citrate-soluble extract for direct determination of available phosphorus can be eliminated. The latter two observations were supported by the results of a collaborative study by 8 analysts on 8 fertilizer materials.

Use of Acetone in the Quinoline Molybdate Reagent for Phosphorus

Abstract The quinoline molybdate method has been simplified considerably by the use of a single precipitating solution. This solution, which contains quinoline, sodium molybdate, citric acid, and acetone, is designated the "quimociac" reagent. Acetone in the reagent eliminates the ammonia interference in the precipitation of quinoline phosphomolybdate and makes the method suitable for the determination of available phosphorus in fertilizers.

Studies on the determination of available phosphorus in soils

Studies on the determination of available phosphorus in soils

Photometric Method for Direct Determination of Available Phosphorus in Fertilizers

Journal Article Photometric Method for Direct Determination of Available Phosphorus in Fertilizers Get access W M Hoffman, W M Hoffman Search for other works by this author on: Oxford Academic Google Scholar J A Brabson, J A Brabson Search for other works by this author on: Oxford Academic Google Scholar W G Burch, Jr, W G Burch, Jr Search for other works by this author on: Oxford Academic Google Scholar C W Gehrke, C W Gehrke Search for other works by this author on: Oxford Academic Google Scholar F J Johnson F J Johnson Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 44, Issue 2, 1 May 1961, Pages 233–239, https://doi.org/10.1093/jaoac/44.2.233 Published: 01 February 2020

Volumetric Method for Direct Determination of Available Phosphorus in Fertilizers

Volumetric Method for Direct Determination of Available Phosphorus in Fertilizers

Direct Determination of Available Phosphorus: Modifications in Chlorate Method for Destruction of Citrate

Direct Determination of Available Phosphorus: Modifications in Chlorate Method for Destruction of Citrate

Phosphorus in Fertilizers: Direct Determination of Available Phosphorus

Phosphorus in Fertilizers: Direct Determination of Available Phosphorus

The Direct Determination of Available Phosphorus in Fertilizers by the Quinolinium Phosphomolybdate Method

Journal Article The Direct Determination of Available Phosphorus in Fertilizers by the Quinolinium Phosphomolybdate Method Get access C H Perrin C H Perrin Canada Packers Ltd., Toronto, Ontario, Canada Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 42, Issue 3, 1 August 1959, Pages 567–568, https://doi.org/10.1093/jaoac/42.3.567 Published: 03 February 2020

Direct Determination of Available Phosphorus in Fertilizers; Use of Sodium Chlorate to Destroy Citrate

Direct Determination of Available Phosphorus in Fertilizers; Use of Sodium Chlorate to Destroy Citrate

Report on Phosphorus in Fertilizers. II. Direct Determination of Available Phosphorus by the Volumetric Method

Report on Phosphorus in Fertilizers. II. Direct Determination of Available Phosphorus by the Volumetric Method

Note on Direct Determination of Available Phosphorus in Fertilizers

Note on Direct Determination of Available Phosphorus in Fertilizers

Factors Affecting the Determination of Available Phosphorus in Calcined Phosphate and Other Water-Insoluble Phosphates

Factors Affecting the Determination of Available Phosphorus in Calcined Phosphate and Other Water-Insoluble Phosphates

A Comparison of the Niklas and Truog Methods for the Determination of Available Phosphorus in Soils1

A Comparison of the Niklas and Truog Methods for the Determination of Available Phosphorus in Soils¹