MINERALIZATION OF SOIL ORGANIC PHOSPHORUS WITH PARTICULAR REFERENCE TO THE EFFECT OF LIME

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.


1962 ◽  
Vol 42 (2) ◽  
pp. 289-295
Author(s):  
A. W. Moore ◽  
H. F. Rhoades

Two wet meadow soils of the Loup series in the Nebraska Sandhills were selected for study because vegetation growing on Soil 1 showed a marked response to phosphate fertilizer whereas that on Soil 2 showed little or no response to phosphate fertilizer.Curves for yields of dry matter indicated that available phosphorus (Mitscherlich "b" value) was much lower in Soil 1 (10 pounds phosphorus per acre) than in Soil 2 (35 pounds phosphorus or more per acre).Using P32-labelled triple superphosphate, it was shown that during the growing season of 1955 the meadow vegetation on Soil 1 derived about twice as much phosphorus from fertilizer as from the soil, while the vegetation on Soil 2 obtained about equal quantities of phosphorus from soil and fertilizer sources.The groundwater from Site 2 contained about three times as much phosphorus as that from Site 1 (0.41 p.p.m. and 0.12 p.p.m. P, respectively).A laboratory study of the mineralization of soil organic phosphorus indicated that in Soil 2 microbiological action released inorganic phosphorus whereas in Soil 1 inorganic phosphorus was assimilated.Differences in phosphorus content of groundwater and in microbial activity were probably responsible for differential responses to phosphorus fertilization obtained in the field.


1959 ◽  
Vol 39 (1) ◽  
pp. 20-26 ◽  
Author(s):  
G. W. Boswall ◽  
W. A. Delong

A mild laboratory procedure, employing oxine in a water-benzene system, for the release of organic phosphorus from two unimproved pasture soils differing widely in total phosphorus, ratio of organic to inorganic phosphorus, pH, calcium content and clay content, is described.Data are presented showing the influence of the following factors on the amount of phosphorus released: soil to water ratio, the pH of the extraction medium, and the soil pretreatments. Under the more favourable conditions the two soils released 75 and 86 per cent of their total organic phosphorus respectively.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Huck Ywih Ch’ng ◽  
Osumanu Haruna Ahmed ◽  
Nik Muhamad Ab. Majid

In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.


1956 ◽  
Vol 28 (1) ◽  
pp. 90-104
Author(s):  
Armi Kaila

In the present paper results are reported concerning the total content as well as solubility of organic and inorganic phosphorus in 122 peat samples which were collected from various depths of 30 peat lands. The total phosphorus content of all the samples was rather low and no regularity in the influence of the depth upon this quantity could be demonstrated. There seemed to be some tendency to an increase in the P-content with increasing depth in the peat lands of lower quality. In peat lands of higher quality the opposite often held true. A large part of the phosphorus occurred in organic form, and, almost without exception, this percentage of total phosphorus increased with the depth: in undecomposed plant material this proportion was about 50—60 per cent, in the surface layers 70 per cent, on the average, in deposits deeper than 50 cm seldom less than 80 per cent and it could even reach 95 per cent. 1he amount of organic phosphorus expressed as a percentage of organic dry matter was low in most of the samples and although it tended to increase with the depth only in 11 of all the 122 samples values higher than 0.1 per cent were obtained. Even if an allowance is made for the conditions prevailing in peat lands these low percentages of organic phosphorus indicate that, from the microbiological point of view, no rapid mineralization of the organic phosphorus compounds is probable. The inorganic phosphorus content was low and tended to decrease from the surface to deeper layers. The solubility of inorganic phosphorus, however, dropped much more drastically. Thus in the deeper layers the amount of easily extractable inorganic phosphorus could be negligible. The solubility of organic phosphorus also impaired with the depth. The phosphorus economy of peat lands was discussed on the basis of the results obtained.


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.


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.


1965 ◽  
Vol 37 (4) ◽  
pp. 243-254
Author(s):  
Armi Kaila

The effect of liming on the soil phosphorus fractions was studied under the laboratory conditions. 28 samples of mineral soils (pH in 0.01 M CaCl2 suspension 4.0 to 6.0) were incubated with 1 per cent CaCO3 or without lime for six months at about 18—20°C. In an other experiment, six samples (pH from 3.3 to 4.3) were incubated with 0, 0.5, 1, or 2 per cent CaCO3 also for six months. At the end of the incubation period the soil pH in the limed samples of the first experiment ranged from pH 5.9 to pH 7.5, in the second experiment the highest application kept the soil pH at 6.5 to 7.0. In the air-dried samples the content of organic phosphorus and the fractions of inorganic phosphorus were determined, and the increases or decreases due to the incubation and liming were calculated. Incubation without lime brought about decrease in the organic phosphorus content of several samples, and the presence of lime tended to intensify this effect, although only in a few cases the decrease due to liming was statistically significant. Liming also tended to increase the accumulation of NH4F-soluble inorganic phosphorus. The acid-soluble fraction was often increased in the limed samples but not in the unlimed ones. The alkali-soluble fraction was decreased in most soils in the limed samples, while it increased in some of the unlimed ones. In the second experiment the incubation caused marked decrease in the alkali-soluble phosphorus without a corresponding increase in the other phosphorus fractions determined in the subsoil samples. It was concluded that in these experiments the relatively heavy liming in the first place affected the distribution of inorganic phosphorus increasing the NH4F-soluble and acid-soluble forms at the expense of the alkali-soluble fraction. The effect on the mineralization of organic phosphorus seemed to be in most soils of minor importance.


2020 ◽  
Vol 143 ◽  
pp. 02024
Author(s):  
Wang Xi ◽  
Lu Shuchang ◽  
Pei Zhiqiang ◽  
Hou Kun ◽  
Ya Zongjie ◽  
...  

In this experiment, the effects of different types of conditioners and their application on the absorption and transformation of phosphorus in high phosphorus soils in facilities were investigated to improve the environmental problems of protected farmland caused by phosphorus accumulation. Waxy corn was used as a test crop, and five conditioners such as humic acid, biochar, bentonite, alum, and dephosphorized gypsum were used as test materials for potting experiments. The experiment set 10 treatments, namely T1(Blank control), T2(Humic acid), T3(Biochar), T4(Bentonite), T5(Alum), T6 (Dephosphorized gypsum), T7(Biochar-bentonite-alum), T8(Humic acid-biochar-alum),T9(Humic acidbiochar- bentonite-alum),T10(Humic acid-bentonite-biochar-alum-dephosphorized gypsum). Based on the analysis of the results of the three crops, except that the first crop was not significant, the biomass and phosphorus absorption of waxy corn of T2 was the highest in the second crop, and T10 was the most effective treatment in the third crop. The soil available phosphorus content of T8 was the lowest in the second crop and that of T10 was the lowest in the third crop, which were 12.01% and 12.75% lower than the control. The soil water-soluble phosphorus content of T4 was the lowest in the second crop, which was 41.84% lower than the control, and that of T8 was the lowest in the third crop, which was 26.62% lower than the control. According to the results of the three crops, the ratio of the total phosphorus content of the inorganic phosphorus in the third crop of each treatment was increasing compared with the first crop. The soil phosphorus was transformed from organic phosphorus to inorganic phosphorus. The ratio of total phosphorus content of organic phosphorus of T6, T9, T10 was larger than other treatments, which slowed down the conversion of phosphorus to available form. The ratio of Ca8-P in the inorganic phosphorus was the highest, reaching about 50% to 60%. From the results and analysis, T2 and T10 were beneficial to the absorption of soil phosphorus by waxy corn, T8 and T10 were beneficial to slow down the conversion of phosphorus to the effective state, reduce the potential risk of phosphorus environment, improve the phosphorus accumulation environmental issues in greenhouse farmland.


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