scholarly journals Relationship between phosphorus intensity and capacity parameters in Finnish mineral soils: II Sorption-desorption isotherms and their relation to soil characteristics

1982 ◽  
Vol 54 (4) ◽  
pp. 251-262
Author(s):  
Helinä Hartikainen
Keyword(s):  
Mineral Soil ◽  
Zero Point ◽  
Soil Characteristics ◽  
Water Soluble ◽  
Clay Soils ◽  
Practical Significance ◽  
Water Soluble P ◽  
P Concentration ◽  
Desorption Isotherms ◽  
Soluble P

The relationship between P intensity and capacity parameters in 104 mineral soil samples was studied by means of sorption-desorption isotherms of two types. In the isotherm A the P exchange was expressed as a function of P concentration in the initial solution, in the isotherm B as a function of P concentration in the final equilibrium solution. Both isotherms conformed to the equation y = a + bx, where y stands for the amount of P sorbed or desorbed and x the P concentration in the solution. In the isotherm A the constant a is the intensity factor expressing the amount of water soluble P at a given soil-solution ratio. The term a in the isotherm B, on the contrary, was only poorly related to water soluble P in soil. In both isotherms the slope b of the line seemed to be most effectively affected by oxalate extractable Al. The relative importance of oxalate soluble Fe appeared to be greater in affecting the effectiveness of sorption-desorption reactions than in affecting the buffer reactions. However, the slope b of both isotherms was found to be a semi-intensive parameter: it was quite markedly dependent also on soil characteristics which control the level of water soluble P in soil. The ratio of the term —a to b (termed as EBS or EPC), expressing the zero point of net P exchange, varied from 0.003 to 13.89 mg P per liter, the lowest values tending to be in the heavy clay soils and the highest ones in the non-clay soils. The practical significance of this quantity was discussed.

scholarly journals Effects of exogenous phytase supplementation on phosphorus metabolism and digestibility of beef cattle

2017 ◽  
Vol 1 (2) ◽  
pp. 168-178
Author(s):  
C. J. Long ◽  
L. B. Kondratovich ◽  
M. F. Westphalen ◽  
H. H. Stein ◽  
T. L. Felix
Keyword(s):  
Beef Cattle ◽  
Latin Square ◽  
Water Soluble ◽  
Experimental Unit ◽  
Water Soluble P ◽  
P Concentration ◽  
Fecal Output ◽  
P Utilization ◽  
Soluble P ◽  
Total P

Abstract Objectives were to determine interactions between phytase inclusion and dietary P concentration on P utilization by beef cattle fed a starch-based diet. Six ruminally-fistulated steers (BW = 750 ± 61 kg) were allotted to a 6 × 6 Latin square design with a 3 × 2 factorial arrangement of treatments. Factors included phytase inclusion, at 0, 500, or 2,000 phytase units (FTU)/kg of diet DM, and dietary P concentrations, at 0.10% and 0.30% of total diet DM. Feed ingredients, fecal samples, and orts were composited within period, lyophilized and ground. Samples were analyzed for NDF, ADF, CP, fat, ash, total P, and other minerals. Data were analyzed using the MIXED procedure of SAS with animal as the experimental unit. The CORR procedure was used to compare blood and urinary P concentrations. There were no treatment interactions (P ≥ 0.30) for any parameter measured. There were no main effects (P ≥ 0.45) of phytase inclusion on DMI, total fecal output, apparent DM digestibility, water intake, or urinary output. Steers fed 0.10% P had decreased (P < 0.01) DMI and total fecal output, but increased (P < 0.01) apparent DM digestibility compared with steers fed 0.30% P. Although N intake and retention were not affected by treatment, steers fed the 0.10% P diet tended (P = 0.10) to absorb more N compared with steers fed 0.30% P; and, steers fed the 0.10% P diets excreted more N in the urine (P = 0.02) and less N in the feces (P < 0.01) compared with steers fed the 0.30% P diets. Steers fed the 0.10% P diets also consumed 70.1% less (P < 0.01) total P each day, and excreted 51.9% less (P < 0.01) P in feces and 94.6% less P in the urine (P < 0.01) compared with steers fed 0.30% P. Excretion of water-soluble P in the feces was greater (P < 0.01) on a g/d basis for steers fed 0.30% P when compared with steers fed 0.10% P. However, the proportion of total fecal P excreted as water-soluble P increased (P < 0.05) by 23.0% in steers fed 0.10% P compared with steers fed 0.30% P, regardless of phytase inclusion level. There was no effect of dietary phytase concentration on blood or urinary (P ≥ 0.27) P concentrations. Blood P concentration was positively correlated (r = 0.60; P < 0.01) to urinary P concentration when steers were fed 0.10% P; however, when steers were fed 0.30% P, there was no correlation (r = 0.36; P = 0.16) between blood and urine P. Regardless of dietary P concentration, phytase supplementation did not increase calculated P absorption or retention.

scholarly journals Chloride and sulphate solutions as extractants for soil P: I Effect of ionic species and ionic strength on P desorption 

1982 ◽  
Vol 54 (4) ◽  
pp. 287-296
Author(s):  
Helinä Hartikainen ◽  
Markku Yli-Halla
Keyword(s):  
Ionic Strength ◽  
Extraction Efficiency ◽  
Mineral Soil ◽  
Water Soluble ◽  
Exchange Reactions ◽  
Salt Solutions ◽  
Chloride Solutions ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

The effect of Cl and SO2-4, anions as well as that of the ionic strength on the desorption of soil P were studied in 102 mineral soil samples by extracting them with KCI and K2SO4 solutions at ionic strengths of 0.025 and 0.1. The quantities of salt soluble and water soluble P in the soils were compared. Both sulphate solutions extracted more P in every single sample than either of the chloride solutions. On the other hand, the material could be divided into three groups according to the position of water in the order of extraction efficiency. In the group W>S>Cl, consisting of 53 samples, water was the most effective extractant, in the group S>W>Cl of 37 samples water was less effective than sulphate solutions but more effective than the chloride solutions, and in 12 samples (S>Cl>W) water was the least effective, less effective than even chloride. The groups classified according to P extractability did not deviate from each other in terms of soil texture, pH or org. C %, but the salt solutions tended to be the more effective extractants the poorer the P status of the soil was. The salt soluble and water soluble P which are closely related to each other correlated with the same factors. Exclusive of the group of 12 samples (S>Cl>W), the highest value sof correlation coefficient were found for NH4F-P/Al, i.e. the molar ratio of NH4F soluble P (CHANG and JACKSON's method) to oxalate extractable Al (r=0.89***-0.93***). The absolute differences between amounts of P dissolved in KCI and K2SO4 solutions of the same initial ionic strength were the greater the more water soluble P the samples contained (r=0.58* -0.94***). An increase in ionic strength tended to depress the extractability of P in both salt solutions. Therefore the ligand exchange between sulphate and phosphate or hydroxyl was regarded unprobable. A theory of the extraction mechanism of sulphate was presented. The greater extraction efficiency of sulphate was assumed to be caused by the exchange reactions with H2O groups which affect the ionic strength in a solution and the electric condition near the surface.

scholarly journals The influence of long-term sewage sludge application on the activity of phosphatases in the rhizosphere of plants

2008 ◽  
Vol 53 (No. 9) ◽  
pp. 375-381 ◽  
Author(s):  
J. Balík ◽  
D. Pavlíková ◽  
V. Vaněk ◽  
M. Kulhánek ◽  
B. Kotková
Keyword(s):  
Sewage Sludge ◽  
Fertilizer Application ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Lower Content ◽  
Alkaline Phosphatases ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

Model experiments using rhizoboxes were carried out in order to evaluate the influence of different plants (wheat, rape) on the changes in water extractable contents of P, the pH/H2O value and the activity of acidic and alkaline phosphatase in soil of plant rhizosphere. For this experiment, a Cambisol with different long-term fertilizing systems was used: (i) control (with no fertilizer application), (ii) sewage sludge, and (iii) manure. A lower content of water-soluble P was observed in close vicinities of root surfaces (up to 2 mm) at all the studied variants. The control (non-treated) variant reflected a significantly lower content of water-soluble P in the rhizosphere compared to the fertilized ones. The activities of the acidic and alkaline phosphatases were significantly higher in the rhizosphere compared to the bulk soil (soil outside the rhizosphere). The long-term application of organic fertilizers significantly increased phosphatase activity; the activity of the acidic phosphatase was significantly higher in the rhizosphere of rape plants compared to wheat. The variant treated with manure exhibited an increased activity of both the acidic and alkaline phosphatases compared to the variant treated with sewage sludge. In the case of the variant treated long-term with sewage sludge, the portion of inorganic P to total soil P content proportionally increased compared to the manure-treated variant. Soil of the rape rhizosphere showed a trend of lower pH/H<sub>2</sub>O value of all variants, whereas the wheat rhizosphere showed an opposite pH tendency.

Water-soluble p-carboxybenzylated beechwood 4-O-methylglucuronoxylan: structural features and properties

2000 ◽  
Vol 42 (2) ◽  
pp. 123-131 ◽  
Author(s):  
A. Ebringerová ◽  
J. Alföldi ◽  
Z. Hromádková ◽  
G.M. Pavlov ◽  
S.E. Harding
Keyword(s):  
Structural Features ◽  
Water Soluble ◽  
Water Soluble P ◽  
Soluble P

A route to virtually unlimited functionalization of water-soluble p-sulfonatocalix[4]arenes

2020 ◽  
Vol 56 (29) ◽  
pp. 4122-4125
Author(s):  
Alexander Gorbunov ◽  
Anna Iskandarova ◽  
Kirill Puchnin ◽  
Valentine Nenajdenko ◽  
Vladimir Kovalev ◽  
...  
Keyword(s):  
Water Soluble ◽  
Reaction Sequence ◽  
Water Soluble P ◽  
Cuaac Reaction ◽  
Soluble P

Diverse narrow-rim derivatives can be easily prepared from p-sulfonatocalix[4]arenes using the propargylation/CuAAC reaction sequence.

Mechanochemical Activation and Characterization of Low-Medium Grade Phosphorite Ore

2013 ◽  
Vol 690-693 ◽  
pp. 3529-3532
Author(s):  
Yu Xing ◽  
Hong Gao ◽  
Yuan Fang Ying ◽  
De Zheng Qu
Keyword(s):  
Mechanochemical Activation ◽  
Planetary Mill ◽  
Water Soluble ◽  
Particle Sizes ◽  
Leaching Rate ◽  
Activation Time ◽  
Activation Effect ◽  
Water Soluble P ◽  
Soluble P

The activation effect of ball-to-powder ratio and activation time on phosphorite ore that takes place in mechanochemical activation has been investigated in present paper, which is carried out in a planetary mill AGO-II. The results show that, particle sizes decreased after activation; the leaching rate of water-soluble P2O5 increased 4.6 percentage as ball-to-powder ratio rose from 8:1 to 40:1; the activated particle of samples has been highly dispersed, while the leaching rate of water-soluble P2O5 reached 10.1% after milling 15 minutes during activation, which was 4 times as high as the un-activated samples. The results show a potential utilization of low-medium grade phosphorite ore with mechanochemical activation directly.

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