Biographical Memoirs Volume 88 (2006) / Chapter Skim
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Stanley Arthur Barber
Stanley Arthur Barber
Pages 24-39
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From page 25... ...
After graduation he remained at home for two more years before following in the footsteps of his two older brothers and enrolling at the University of Sasakatchewan. During his time at Saskatchewan, which coincied with World War II, his schedule alternated farming in the summer with studying and training with the University Officer Training Corps during the winter.
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From page 26... ...
Professor Marshall, known as a rigorous mentor, was one of the best known and most accomplished soil chemists in the United States. By coming to the United States, Barber followed in the footsteps of many Canadians -- such as Philip Low -- who chose to study agriculture in the USA, thus enriching the lives of his colleagues in the United States.
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From page 27... ...
The second part is the group of forces that move the nutrient ions (electrically charged atoms or molecules) from the soil-water solution surrounding the plant root into the root themselves.
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From page 28... ...
Next to the roots the concentration is reduced by ion or nutrient uptake and these are in turn replaced by this diffusion process. Nutrient ions move through the soil at different rates depending upon the geometry of the soil particles, so the diffusion coefficient is characterized by the soil water content and the soil texture.
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From page 29... ...
Root diameter, length, and growth rate define the amount of root surface area available for nutrient uptake and increase as a plant grows. Barber calculated total root surface by measuring root radius and length to calculate the area of the roots, as though they were a long cylinder for which one could calculate the surface area by multiplying the circumference by the length.
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From page 30... ...
To account for the competition between roots, Barber used an iterative process starting with one section of root at the start of a plant growth. The equations must be solved simultaneously, and then this result must be used with the knowledge of the plant's growth rate to calculate the total uptake of the growing plant.
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From page 31... ...
This and similar studies began to explain the uptake of P by the plant and helped him begin the first states of his eventual model. By 1961 and 1962 Barber had published two papers that contributed to this understanding of the uptake of ions by plant roots followed by a concept of movement of ions to the plant root combing diffu
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From page 32... ...
Soon after, he included the effect of pH changes that are induced by the plant at its root surface comparing ammonium, nitrate, and phosphorous uptake. During the ensuing years Barber studied such variables as ammonium and nitrate uptake as influenced by the NH4 / + NO3 ratio, the uptake per unit of corn roots, and a method for characterizing the relation between nutrient concentration, the development of corn roots, and the effect of this development upon uptake.
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From page 33... ...
His sensitivity analyses of the model showed that root morphology and initial nutrient concentration in the soil solution had the greatest effects on nutrient uptake. The value of each parameter incorporates temperature, if necessary, which may have a significant effect upon water uptake.
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From page 34... ...
He was given the Herbert Newby McCoy Award by Purdue University and an honorary doctor of laws degree and the Distinguished Graduate in Agriculture Award by the University of Saskatchewan, all in 1986. In 1987 he was awarded the Certificate of Distinction by the Purdue Alumni Association and the Gamma Sigma Delta International Award for Distinguished Service to Agriculture, and was the Canadian Industries Ltd.
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From page 35... ...
INFLUENCE ON THE FIELD OF SOIL SCIENCE Stanley Barber's influence on soil science and its related fields, such as ecology and plant breeding, to name just two, is unparalleled by any of his peers. Barber provided a theory-based understanding of all the processes involved in nutrient uptake, while rendering superfluous the conduction of the uptake by plants from every soil and in every climate, as was heretofore the practice.
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From page 36... ...
In Limiting Steps in Ion Uptake by Plants from Soil. International Atomic Energy Agency Technical Report No.
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From page 37... ...
Effect of ammonium and nitrate fertilization on phos phorous fertilization on phosphorous uptake as related to root induced pH changes at the root-soil interface.
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From page 38... ...
Modeling magnesium, phosphorous, and potas sium uptake by loblolly pine seedlings using a Barber-Cushman approach. Plant Soil 139:209-218.
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