The slow reactions between soil and anions: 4. effect of time and temperature of contact between soil and molybdate on the uptake of molybdenum by plants and on the molybdate concentration in the soil solution

N. J. Barrow, T. C. Shaw

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Molybdate solutions were mixed with soil and incubated at constant temperatures for up to 224 days. The uptake of molybdate by plants was then measured. Uptake decreased with increasing period of contact. The rate of decrease was greatest when the temperature of incubation was high. It is argued that the decreased uptake was due to slow conversion of the adsorbed molybdate into a more tightly bound form. This process was studied by measuring its effect on the concentration of molybdate in solutions in equilibrium with the soil. Equations were developed to describe the effects of time and temperature on the decrease in solution concentration. As had been observed in analogous work with phosphate, these equations described the effects closely. Neither the rate of change of concentration nor the effects of temperature on the change was related to soil pH. Because high temperatures of incubation accelerated the change to a more tightly bound form, they also resulted in low solution concentration. However, the equilibrium between adsorbed molybdate and solution molybdate was affected differently by temperature, and high temperatures resulted in high solution concentration. Hence the adsorption reaction was exothermic.

Original languageEnglish
Pages (from-to)301-310
Number of pages10
JournalSoil Science
Volume119
Issue number4
DOIs
Publication statusPublished - 1 Jan 1975
Externally publishedYes

Fingerprint

molybdates
molybdenum
soil solution
anions
anion
soil
temperature
incubation
effect
soil pH
phosphate
adsorption
phosphates

Cite this

@article{f6ef3cf614dc41ffb2da37e980743ed9,
title = "The slow reactions between soil and anions: 4. effect of time and temperature of contact between soil and molybdate on the uptake of molybdenum by plants and on the molybdate concentration in the soil solution",
abstract = "Molybdate solutions were mixed with soil and incubated at constant temperatures for up to 224 days. The uptake of molybdate by plants was then measured. Uptake decreased with increasing period of contact. The rate of decrease was greatest when the temperature of incubation was high. It is argued that the decreased uptake was due to slow conversion of the adsorbed molybdate into a more tightly bound form. This process was studied by measuring its effect on the concentration of molybdate in solutions in equilibrium with the soil. Equations were developed to describe the effects of time and temperature on the decrease in solution concentration. As had been observed in analogous work with phosphate, these equations described the effects closely. Neither the rate of change of concentration nor the effects of temperature on the change was related to soil pH. Because high temperatures of incubation accelerated the change to a more tightly bound form, they also resulted in low solution concentration. However, the equilibrium between adsorbed molybdate and solution molybdate was affected differently by temperature, and high temperatures resulted in high solution concentration. Hence the adsorption reaction was exothermic.",
author = "Barrow, {N. J.} and Shaw, {T. C.}",
year = "1975",
month = "1",
day = "1",
doi = "10.1097/00010694-197504000-00008",
language = "English",
volume = "119",
pages = "301--310",
journal = "Soil Science",
issn = "0038-075X",
publisher = "Lippincott Williams & Wilkins",
number = "4",

}

TY - JOUR

T1 - The slow reactions between soil and anions

T2 - 4. effect of time and temperature of contact between soil and molybdate on the uptake of molybdenum by plants and on the molybdate concentration in the soil solution

AU - Barrow, N. J.

AU - Shaw, T. C.

PY - 1975/1/1

Y1 - 1975/1/1

N2 - Molybdate solutions were mixed with soil and incubated at constant temperatures for up to 224 days. The uptake of molybdate by plants was then measured. Uptake decreased with increasing period of contact. The rate of decrease was greatest when the temperature of incubation was high. It is argued that the decreased uptake was due to slow conversion of the adsorbed molybdate into a more tightly bound form. This process was studied by measuring its effect on the concentration of molybdate in solutions in equilibrium with the soil. Equations were developed to describe the effects of time and temperature on the decrease in solution concentration. As had been observed in analogous work with phosphate, these equations described the effects closely. Neither the rate of change of concentration nor the effects of temperature on the change was related to soil pH. Because high temperatures of incubation accelerated the change to a more tightly bound form, they also resulted in low solution concentration. However, the equilibrium between adsorbed molybdate and solution molybdate was affected differently by temperature, and high temperatures resulted in high solution concentration. Hence the adsorption reaction was exothermic.

AB - Molybdate solutions were mixed with soil and incubated at constant temperatures for up to 224 days. The uptake of molybdate by plants was then measured. Uptake decreased with increasing period of contact. The rate of decrease was greatest when the temperature of incubation was high. It is argued that the decreased uptake was due to slow conversion of the adsorbed molybdate into a more tightly bound form. This process was studied by measuring its effect on the concentration of molybdate in solutions in equilibrium with the soil. Equations were developed to describe the effects of time and temperature on the decrease in solution concentration. As had been observed in analogous work with phosphate, these equations described the effects closely. Neither the rate of change of concentration nor the effects of temperature on the change was related to soil pH. Because high temperatures of incubation accelerated the change to a more tightly bound form, they also resulted in low solution concentration. However, the equilibrium between adsorbed molybdate and solution molybdate was affected differently by temperature, and high temperatures resulted in high solution concentration. Hence the adsorption reaction was exothermic.

UR - http://www.scopus.com/inward/record.url?scp=84934726924&partnerID=8YFLogxK

U2 - 10.1097/00010694-197504000-00008

DO - 10.1097/00010694-197504000-00008

M3 - Article

VL - 119

SP - 301

EP - 310

JO - Soil Science

JF - Soil Science

SN - 0038-075X

IS - 4

ER -