Comparison of five soil testing methods to establish phosphorus sufficiency levels in soil fertilized with water-soluble and sparingly soluble-P sources

1991 ◽  
Vol 28 (3) ◽  
pp. 271-279 ◽  
Author(s):  
A. Bationo ◽  
W. E. Baethgen ◽  
C. B. Christianson ◽  
A. U. Mokwunye
Keyword(s):  
Water Soluble ◽  
Soil Testing ◽  
Testing Methods ◽  
Soluble P ◽  
P Sources

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
Keyword(s):  
Rating Scale ◽  
Soil Samples ◽  
Water Soluble ◽  
Water Extraction ◽  
Molar Ratio ◽  
Acetate Solution ◽  
Testing Methods ◽  
Water Soluble P ◽  
Soluble P ◽  
The Difference

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.

Soil Testing Methods and Apparatus Designed for Economy in Time and Labor 1

1941 ◽  
Vol 33 (7) ◽  
pp. 623-631 ◽  
Author(s):  
E. W. Constable ◽  
I. E. Miles
Keyword(s):  
Soil Testing ◽  
Testing Methods

scholarly journals Field evaluation of water or citrate soluble phosphorus in modified phosphate rocks for soybean

2001 ◽  
Vol 58 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
José Francisco da Cunha ◽  
Ariel Francisco Candiotti Ventimiglia
Keyword(s):  
Field Evaluation ◽  
Water Soluble ◽  
Ammonium Citrate ◽  
Low Grade ◽  
Triple Superphosphate ◽  
Single Superphosphate ◽  
Standard Source ◽  
Extractable P ◽  
P Fertilizers ◽  
P Sources

Ten P fertilizers were collected (commercial fertilizers) or synthesized (experimental sources) in order to obtain single superphosphates varying in water and citrate solubility. A standard source of P was also produced by crystallization of the water-soluble fraction of a triple superphosphate. Eleven P sources were band applied to a medium textured Xanthic Hapludox, in Bahia, Brazil (low content of resin-extractable P) at a rate of 80 kg ha-1 of NAC + H2O (neutral ammonium citrate plus water) soluble P2O5, with soybean as the crop which was grown to maturity. A check plot (control) was included in the study. Three of the P sources [single superphosphate produced from Araxa phosphate rock (PR), low-grade single superphosphate produced from Lagamar PR and the standard source of P] were also applied at rates to provide 40 and 120 kg ha-1 of NAC + H2O soluble P2O5. Yield of soybean was evaluated by analysis of variance with mean comparison performed utilizing LSD lines, considering the P sources applied at a rate of 80 kg ha-1 of P2O5 + control. Regression procedures were used to study the relation between yield of soybean and rates of P2O5. The fertilizers tested performed equally well as a source of P for soybean. The level of water-soluble P did not influence fertilizer performance.

scholarly journals Soil phosphorus availability and soybean response to phosphorus starter fertilizer

2014 ◽  
Vol 38 (5) ◽  
pp. 1487-1495 ◽  
Author(s):  
Ciro Antonio Rosolem ◽  
Alexandre Merlin
Keyword(s):  
Soil Phosphorus ◽  
Soil Surface ◽  
Tropical Soils ◽  
P Fertilization ◽  
Soil P ◽  
Brachiaria Ruziziensis ◽  
Soluble P ◽  
Surface Spread ◽  
P Sources

Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis). No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.

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
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