HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mortvedt, J. J. Articles by Osborn, G. Search for Related Content PubMed Articles by Mortvedt, J. J. Articles by Osborn, G. Agricola Articles by Mortvedt, J. J. Articles by Osborn, G.

Boron Concentration Adjacent to Fertilizer Granules in Soil, and Its Effect on Root Growth¹

ABSTRACT

Rates of dissolution of B from granules of rasorite and three boronated fertilizers in limed Hartsells fine sandy loam decreased in the order: Nitric phosphate (2.2% B) > rasorite (20.2% B) >> calcium silicate slag (7.5% B) > calcium metaphosphate (2.1% B). Movement of B from the granules increased with B concentration gradient and soil moisture content.

Concentration of hot water-soluble B in soil near the granules at a given time depended on: (i) B content of the granule, and (ii) the relative rates of B dissolution from the granule and movement of B from the granule site. Concentrations of B near rasorite granules—as high as 80 parts per million (ppm) in a large volume (4 kg of soil in gallon cans) and 385 ppm in thin soil layers (80 g of soil in Petri dishes)—were inversely proportional to the amount of soil affected.

Root growth of oats and alfalfa was slightly depressed at soil B concentrations of 2 to 5 ppm, and markedly so at concentrations above 10 ppm B. Thus, high concentrations in soil near some B sources may inhibit root growth. Root injury may be prevented by decreasing the B content per fertilizer granule and by applying less soluble sources or lower amounts of B.

¹ Contribution of the Soils and Fertilizer Research Branch, Div. of Agricultural Development, TVA, Wilson Dam, Ala. Portions of this paper were presented before Div. S-2, Soil Science Society of America, Nov. 19, 1963, at Denver, Colo.

² Soil Chemist and Analytical Chemist, respectively. W. C. Stephens and B. N. Bradford assisted in the growth chamber study. Boronated fertilizers were prepared by the Division of Chemical Development, TVA.

Received for publication August 3, 1964. Accepted for publication September 11, 1964.