INOSITOL PHOSPHATE AND ORGANIC PHOSPHORUS CONTENTS AND PHOSPHATASE ACTIVITY OF SOME CANADIAN AND GHANAIAN SOILS

1982 ◽  
Vol 62 (1) ◽  
pp. 31-38 ◽  
Author(s):  
M. R. APPIAH ◽  
R. L. THOMAS

Total organic phosphorus, inositol phosphates and phosphatase activity of some selected Canadian and Ghanaian soils were compared. The lower organic phosphorus content of Ghanaian soils compared to the Canadian soils may be the result of either the faster rate of mineralization of organic phosphorus in the tropical Ghanaian soils or differences in the nature of organic residues returned to the soils. Wide variations in the amounts of inositol phosphate were observed in both groups of soils. The low activity of phosphatases in the Ghanaian soils may be due to the lower content of organic matter, a lower microbial biomass and consequently a lower phosphatase production. The effect of rotation and fertilizer application on the total organic P, inositol P and phosphatase activity indicated that alfalfa grown in rotation with corn and oats contributed significantly to the total soil organic phosphorus content with no apparent increase in inositol phosphate content. No consistent trends were observed in either the total amount of inositol phosphates or the proportion of the total phosphorus that existed as inositol phosphates for either the fertilized or unfertilized soils. The activity of phosphatase was generally higher in the corn-oat-alfalfa rotation than in the systems of corn-oat and continuous corn. Fertilization decreased the phosphatase activity in all cropping systems.

1963 ◽  
Vol 43 (1) ◽  
pp. 97-106 ◽  
Author(s):  
R. L. Halstead ◽  
J. M. Lapensee ◽  
K. C. Ivarson

In a laboratory experiment, liming resulted in an average decline of 3.6 per cent in the total organic phosphorus content of incubated surface samples of seven acid soils from eastern Canada. Increases of 2.6 and 5.1 per cent in 1N H2SO4- and 4N HCl-soluble inorganic phosphorus, respectively, and a decrease of 46.4 per cent in NaHCO3-soluble organic phosphorus (pH 8.5) provided further evidence of mineralization of organic phosphorus following liming. There was some evidence, however, that the differences in NaHCO3-soluble organic phosphorus following liming were due only in part to mineralization, since Ca(OH)2 added to a soil just prior to extraction with NaHCO3 had a repressive effect on the solubility of the organic phosphorus compounds.Some mineralization of organic phosphorus occurred when unlimed samples were incubated in the laboratory for 9 months.Marked increases in microbiological activity, as indicated by increased numbers of microorganisms, and increased CO2 and NO3-nitrogen production, were associated with lower values for extractable organic phosphorus following liming. Partial sterilization of samples with toluene lowered biological activity in the unlimed and limed samples. Toluene was found, however, to have a positive effect on release of phosphorus from organic form.


1961 ◽  
Vol 12 (1) ◽  
pp. 111 ◽  
Author(s):  
SM Bromfield

Faeces from sheep grazing naturalDanthonia pastures and improved subterranean clover pastures have been analysed for total phosphorus and inorganic phosphate over a period of 2 years. Both total and inorganic phosphorus contents (milligrams P per gram) varied widely with type of pasture and with season. The variation in organic phosphorus content (by difference) remained, relative to total phosphorus, fairly constant throughout. Total phosphorus content varied from 1.8 to 17 mg P/g whilst organic phosphorus varied from 1.5 to 4.0 mg P/g. Sheep grazing the improved pastures voided approximately 2.5–3 lb P as inorganic phosphate and 0.5–0.75 lb P as organic phosphorus per sheep per year. The inorganic phosphate was readily soluble in acid but not in water and was readily available to wheat grown in pot culture. The organic phosphorus was not readily available to plants and was not rapidly mineralized to inorganic phosphate. The contribution faecal phosphorus makes to the nutrition of pastures and to the reserve of soil organic phosphorus is briefly discussed.


2020 ◽  
Vol 22 (4) ◽  
pp. 1084-1094 ◽  
Author(s):  
Jolanda E. Reusser ◽  
René Verel ◽  
Emmanuel Frossard ◽  
Timothy I. McLaren

Inositol phosphates, particularly myo-inositol hexakisphosphate (myo-IP6), are an important pool of soil organic phosphorus (P) in terrestrial ecosystems.


Soil Research ◽  
1963 ◽  
Vol 1 (2) ◽  
pp. 203 ◽  
Author(s):  
DJ Cosgrove

Gradient elution chromatography, using a column of anion exchange resin, Dowex AG I-X8, has been used to separate and isolate constituents of the 'phytin' fraction of soil organic matter. In addition to the commonly occurring myoinositol hexaphosphate the presence of the corresponding derivatives of DL-inositol and scylloinositol was demonstrated. Of the lower inositol phosphates present pentaphosphates appeared to be the major constituents. The occurrence in nature of inositols, other than the myoinositol, as phosphorylated derivatives, has not previously been recorded. Present knowledge is insufficient to decide whether soil inositol phosphates are of plant origin or accumulated through the activities of soil microorganisms.


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