scholarly journals Effect of cumulative fertilizer dressings on the phosphorus status of mineral soils II Comparison of two phosphorus testing methods

1989 ◽  
Vol 61 (2) ◽  
pp. 61-66
Author(s):  
Helinä Hartikainen

Soil samples collected from field plots before onset of fertilization trials and after seven years of cultivation with annual P additions of 0, 30 or 60 kg ha-1, were analyzed for water-soluble P (Pw) and acid NH4-acetate-extractable P (PAAc). In all soil samples, the P test values correlated closely (r = 0.93***). However, they differed significantly in the clay soils where PAAc amounted to 59—96 % of Pw . In the coarser soils, the acetate solution extracted 70—365 % of the water-soluble P, but the difference between the methods remained insignificant. In both soil groups, the molar ratio of NH4F-P to oxalate-soluble Al explained 90 % or more of the variation in the P test values. The soil samples were divided into different P content classes according to the acetate test calibration scheme. In various P classes the test values tended to differ statistically significantly: in the lower classes acetate extracted P more and in the higher classes less than water did. Only in soils ranked as satisfactory in P the test values were about equal. When the rating scale limits given for the advisory soil testing were applied to the water extraction, in most soils the difference between the P testing methods was of one P class. The fertilization recommendations based on the acetate and water extraction tests were compared.

1983 ◽  
Vol 55 (4) ◽  
pp. 345-354
Author(s):  
Helinä Hartikainen

The effect of increasing lime quantities on reactions of native and applied P was investigated in an incubation experiment performed with two acid mineral soils of pH 4.8 (CaCl2). The soil samples differed considerably in the content of organic matter, which was reflected in their pH buffering power: in the fine sand, rich in organic matter (6.4 % org. C), liming raised the pH less than in the muddy fine sand (3.0 % org. C). The level of native water-soluble P was markedly lowered in the incubated soil samples treated with nutrient salts. In the muddy fine sand, the decrease tended to be the smaller, whereas in the fine sand the greater, the more intensive liming was. This held true also of added P. The changes in CHANG and JACKSON’s P fractions did not alone satisfactorily explain the dissimilar response of soil P to lime treatments. The fate of P was concluded to be controlled by the quality and quantity of Al species differing in their affinity for P sorption. The changes in the solubility of P are a net result of processes enhancing and of those depressing the sorption tendency. In the fine sand soil of high initial content of water-soluble P, the detrimental effect of liming seemed to be attributed to the abundance of polymerized Al the affinity of which for P retention increased with intensified liming. Further, the high pH buffering power of this soil reduced the efficiency of lime to produce OH- ions able to compete with phosphate for sorption sites. In the muddy fine sand soil, on the contrary, the formation of sorption-active sites was not equally marked and, owing to the weaker pH buffering, liming raised the OH- concentration more effectively.


2008 ◽  
Vol 53 (No. 9) ◽  
pp. 375-381 ◽  
Author(s):  
J. Balík ◽  
D. Pavlíková ◽  
V. Vaněk ◽  
M. Kulhánek ◽  
B. Kotková

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.


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

2020 ◽  
Vol 56 (29) ◽  
pp. 4122-4125
Author(s):  
Alexander Gorbunov ◽  
Anna Iskandarova ◽  
Kirill Puchnin ◽  
Valentine Nenajdenko ◽  
Vladimir Kovalev ◽  
...  

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


2013 ◽  
Vol 690-693 ◽  
pp. 3529-3532
Author(s):  
Yu Xing ◽  
Hong Gao ◽  
Yuan Fang Ying ◽  
De Zheng Qu

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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