Phosphate responses in relation to soil tests and organic phosphorus

1960 ◽  
Vol 54 (3) ◽  
pp. 341-347 ◽  
Author(s):  
M. T. Friend ◽  
H. F. Birch

Phosphate responses of wheat in a number of soil types have been correlated with the amounts of phosphate extracted by ten different methods. Of these only total organic phosphorus, and inorganic phosphorus extracted with hot 0·1N caustic soda, were significantly related to phosphate response, the former at the 1% level and the latter at the 5% level. The amount of organic phosphorus in the soil was also found to be significantly related, in each instance at the 5% level, to phosphate responses of grass and the percentage phosphate in the grass. When the amount of organic phosphorus was considered together with the phosphate retention capacity of the soil, to give a measure of available mineralized phosphate, the relationships to response (and uptake of phosphorus by grasses) was more significant than with organic phosphorus alone.The organic phosphorus fraction accounted for about 86% of the total soil phosphorus. Measurable amounts of water-soluble organic phosphorus were found with all the soils. The amounts were, however, not significantly related to phosphate response. Moreover, it was found that while the soil extract containing organic phosphorus decomposed, it did so without the production of mineral phosphate. From this, and further evidence in the literature, it is considered that the organic complex in the soil, rather than the water soluble phosphorus, is the main source for the plant.

1938 ◽  
Vol 28 (2) ◽  
pp. 234-246 ◽  
Author(s):  
L. A. Dean

1. Extractions of soils with sodium hydroxide, followed by an acid, have been used in an attempt to fractionate the soil phosphorus.2. Colorimetric methods for the estimation of the organic and inorganic phosphorus in alkali soil extracts have been suggested.3. The amount of soil phosphorus soluble in sodium hydroxide is affected by the active soil calcium. It is suggested that sodium-saturated soils be used when studying the alkali-soluble phosphorus.4. The acid-soluble phosphorus remaining in soil after extraction with sodium hydroxide was determined. This fraction appears by analogy to be similar to the apatites.5. The largest fraction of the total soil phosphorus was not dissolved by the sodium hydroxide and acid extractions. This fraction was not increased by the long-continued use of phosphatic fertilizers at Rothamsted and Woburn.6. Relatively large amounts of organic phosphorus were found in soils and the amounts were closely related to the carbon contents.


Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 383 ◽  
Author(s):  
KW Perrott ◽  
SU Sarathchandra ◽  
BW Dow

A two year investigation of soil phosphorus and the soil organic cycle was carried out on a typical hill country site in the North Island, New Zealand. This included investigation of changes in soil phosphorus, as well as seasonal and fertilizer (superphosphate) effects on soil microbial phosphorus and sulfur, sodium bicarbonate extractable phosphorus and calcium chloride extractable sulfur. No net utilization of soil organic phosphorus occurred when application of phosphate fertilizer was withheld. On the contrary, accumulation of organic phosphorus was found in both fertilized and unfertilized plots. Immobilization of inorganic phosphorus into organic forms appeared to be a significant factor in fertilizer phosphorus requirements at this site. It was also a significant cause of the decline in the soil phosphorus status when no fertilizer was applied. Despite declining pasture production, there were no effects of withholding superphosphate on the soil biological cycle as measured by soil microbial phosphorus and sulfur, total organic phosphorus and sodium bicarbonate extractable organic phosphorus. However, seasonal variations occurred indicating storage and release of phosphorus by the soil organic matter and microbial biomass. Release of phosphorus occurred during periods of rapid pasture growth and could account for phosphorus uptake by the pasture at those times.


1966 ◽  
Vol 17 (3) ◽  
pp. 303 ◽  
Author(s):  
AJ Rixon

Changes in phosphorus applied as superphosphate to irrigated pastures on a red-brown earth were studied for a 4 year period commencing 1 year after the establishment of the pastures. The pastures consisted of Wimmera ryegrass (Lolium rigidum Gaud.), perennial ryegrass (L. perenne L.), subterranean clover (Trifolium subterraneum L.), and white clover (T. repens L.). Measurements of phosphorus fractions were made on the 0–3 in. soil horizon over this period and, for the final 2 years, on the organic matter layer (mat) which was present on the soil surface under all pastures. The mat was shown to be an important accumulation site for organic phosphorus, as well as for inorganic phosphorus which accumulates from interception of broadcast applications of superphosphate. Of the 155 lb phosphorus per acre added as fertilizer, 82–100% was accounted for principally as increases in the acetic acid-soluble fraction or as organic phosphorus. There were no significant changes in the inorganic phosphorus fraction soluble in sodium hydroxide. It was concluded that the amount of phosphorus converted to the organic form will determine the level for maintenance applications of phosphorus on the irrigated pastures.


1960 ◽  
Vol 40 (1) ◽  
pp. 71-79
Author(s):  
H. A. Hamilton ◽  
J. R. Lessard

Soil samples were collected at four different depths from a virgin soil, and in a region where deep ploughing has been a common practice. Chemical analyses revealed that the sub-surface samples were more highly saturated with bases than were the surface samples. In the 0–6 inch layer the percentage contribution of calcium, aluminium and iron phosphate to total soil phosphorus was 41.1, 10.4 and 2.8 respectively; while, in the 18–24 inch layer the percentages were 88.4, 2.8 and 0.5 respectively. Organic phosphorus decreased with depth.In the greenhouse there were highly significant differences between oat yields on the various layers, the surface soil giving the highest yields. Clover crop yields tended to be better as depth of profile increased. Phosphorus increased oat yields and clover yields on all soil layers. As a result of over-liming in certain instances clover yields were depressed in the absence of applied phosphate fertilizer, whereas oat yields were unaffected.


2012 ◽  
Vol 518-523 ◽  
pp. 4801-4805
Author(s):  
Li Xin Chen ◽  
Wen Biao Duan

Variation in total phosphorus (TP), available phosphorus (AP), the forms of organic phosphorus (OP) and inorganic phosphorus (IP) in rhizosphere soil (RS) and non-rhizosphere soil (NRS) at different development stages in larch (Larix olgensis) plantations was quantitively studied through field investigation, chemical analysis and statistical test. The results indicated that: AP, O-P (occluded phosphate), TP, OP in RS exhibited a significantly or apparently decreased tendency over stand age, but IP, Ca-P (phosphate combined with calcium) and Fe-P (phosphate combined with Ferrum) in RS presented a significantly or apparently increased trend when stand age increased; Ca-P in NRS increased when stand age became larger; Fe-P in half-mature stand (HMS), AP and Fe-P in near mature stand (NMS), AP and Ca-P in mature stand (MS) in NRS was higher than in RS


2008 ◽  
Vol 88 (5) ◽  
pp. 709-718
Author(s):  
M K Idowu ◽  
D V Ige ◽  
O O Akinremi

Understanding the effects of organic amendments on the movement of organic and inorganic phosphorus (P) in soils is important for effective P management in agricultural soils. Thus, the effects of beef cattle manure, hog manure and biosolids on the downward movement of organic (Porg) and inorganic (Pi) P in Lakeland and Osborne soils were investigated. The amendments were added to the soils at the rate of 0, 200, 400 and 800 kg P ha-1 by mixing with the top 1 cm of soil in a column. The column was eluted with 20 pore volumes (PV) of 0.01 M CaCl2. The amount of total P (PT), Porg and Pi in the effluent was determined. The concentrations of Porg and Pi in the effluent increased as the rate of amendment application increased. A greater percentage of PT was lost as Pi in the soils amended with hog manure and biosolids, while in the soil amended with beef cattle manure, Porg constituted a greater portion of the total P eluted. As much as 63% of total P eluted from the Lakeland soil at the highest rate of beef cattle manure was in the form of Porg. Lakeland soil retained more Pi than the Osborne soil due to its greater P retention capacity. Organic P was lost within the 2nd and the 4th PV in the two soils, which illustrated the ease of Porg movement through the soil. In conclusion, both organic and inorganic P can move through the soil in organically amended soils and the risk of losing organic P by leaching is greater in soils amended with high rates of beef cattle manure. Key words: Biosolids, hog manure, beef cattle manure, elution, organic phosphorus, inorganic phosphorus


Soil Research ◽  
1987 ◽  
Vol 25 (2) ◽  
pp. 193 ◽  
Author(s):  
DC Lewis ◽  
AL Clarke ◽  
WB Hall

The accumulation of phosphorus applied as superphosphate over a 25-year period to pastures growing on sand over clay soils was measured in three areas of different rainfall in the south-east of South Australia. Total soil phosphorus levels increased in the 0-10 cm, 10-30 cm and 30 cm-clay layers for all areas, but no accumulation occurred in the clay layer. For every 100 kg ha-1 of single superphosphate (9.6% phosphorus) applied, 2.0, 3.2 and 3.5 kg ha-1 of phosphorus accumulated in the 0-10 cm layer for the Hundreds of Coles, Willalooka and Senior respectively. The recoveries of applied phosphorus in the sand layer for the three areas were 42, 57 and 75% for Coles, Willalooka and Senior respectively. The annual accumulation rates of organic phosphorus in the top 30 cm of soil ranged from 2.4 to 3.5 kg ha-1. By using a 'balance sheet' approach, the annual maintenance phosphate requirements for the three areas were calculated. These ranged from 60 to 165 kg ha-1 of superphosphate, and were associated with differences in leaching losses, stocking rates and organic phosphorus accumulation.


1939 ◽  
Vol 17b (7) ◽  
pp. 199-205 ◽  
Author(s):  
C. L. Wrenshall ◽  
W. J. Dyer

Dissolved organic phosphorus may be determined, even in highly coloured alkaline soil extracts, by the application of photoelectric colorimetry to the ceruleomolybdate colour reaction of phosphate ions. Total organic phosphorus may be extracted from soil with 4 N hydrochloric acid followed by treatment of the residue with 3 N ammonium hydroxide. Inorganic phosphorus is determined by direct colorimetry in the acid extract and in the acidified alkaline extract. Total phosphorus is determined similarly in each extract after ignition. The difference between total and inorganic phosphorus is equivalent to the organically combined phosphorus content of the soil sample.The soil organic phosphorus was found to be stable under these treatments. A considerable proportion of the organic phosphorus is extracted by acid, and the total soil phosphorus is almost completely extracted by the two treatments with 4 N hydrochloric acid and 3 N ammonium hydroxide.


Author(s):  
K.W. Perrott

Changes in phosphorus (P) fractions of unfertilised and fertilised (superphosphate) soil were investigated over five years at a hill country site near Te Kuiti. Only soil inorganic P (Pi) reserves were utilised for plant uptake when superphosphate was withheld at the site. Immobilisation of P as soil organic P (PO) contributed to depletion of the soil Pi reserves during the first two years of this trial. Where superphosphate was applied, immobilisation of P as PO amounted to about 25% of applied P during the five years measurements were made. Changes in soil P fractions indicated that all forms of soil Pi were utilised when superphosphate was withheld. These included readily available Pi, Al- Pi, Fe-Pi, and residual phosphate rock from previous fertiliser applications. Depletion of the phosphate rock residues in the soil also occurred where superphosphate was applied and appears to have been completed within about two years. The phosphate rock residues had probably accumulated because of the relatively high amounts of unacidulated phosphate rock in superphosphate manufactured before 1983. Accumulation of Po associated with humic acid, or adsorbed on surfaces of hy drous oxides of Al and Fe, occurred in both fertilised and unfertilised soils. The more labile forms of PO also increased in the fertilised soil. Keywords inorganic phosphorus, organic phosphorus, phosphorus immobilisation, soil phosphorus, soil phosphorus fractions, soil phosphorus utilisation.


1964 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Armi Kaila

Inorganic phosphorus in 363 samples of Finnish mineral soils was fractionated by the procedure of CHANG and JACKSON. The average content of total inorganic phosphorus determined as the difference of the total phosphorus and organic phosphorus tended to increase from sand to clay soils. The sand and fine sand soils appeared to be richer in fluoride-soluble phosphorus but poorer in acid-soluble phosphorus than the other groups of soils. The part of phosphorus extracted by alkali seemed to be almost independent on the soil texture. In about 60 per cent of the samples the acid-soluble phosphorus was the dominant inorganic phosphorus fraction, in spite of the often high acidity of the soil. This, in connection with the rather low content of reductant soluble phosphorus, was taken to indicate the relatively low degree of weathering in these soils. The higher contents of fluoride-soluble and alkali-soluble phosphorus in the surface samples of the cultivated soils as compared with the corresponding kind of virgin soils or soils from the deeper layers may be mainly attributed to the application of phosphorus fertilizers and to a somewhat higher degree of weathering. The soil pH did not seem to play any important role among the factors related to the distribution of inorganic phosphorus into various fractions in the present material. This was particularly true in the cultivated surface soils. It is likely, that in our soils the variation in the contents of active iron and aluminium will to a higher degree than pH explain the variation in the fractions of alkali-soluble and fuoride-soluble phosphorus. The relatively high content of the latter fraction in the sand and fine sand soils as compared with the soils of the finer texture could be related to the higher ratio of ammonium oxalate soluble aluminium to iron in the former soils.


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