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 Tucker, T. C. Articles by Lynch, D. L. Search for Related Content PubMed Articles by Tucker, T. C. Articles by Lynch, D. L. Agricola Articles by Tucker, T. C. Articles by Lynch, D. L.

Zinc Status of Some Illinois Soils as Estimated by an Aspergillus Niger Method¹

ABSTRACT

An extremely sensitive semiquantitative method for bio-assay of zinc in soils with Aspergillus niger is described. Data at present do not permit the validation of the assay as an index of response by higher plants on soils of Illinois. Present investigations are being conducted to locate soils that will respond to zinc fertilization. It is hoped that these studies will show a positive relationship between the bio-assay of zinc in the soil and crop response, and perhaps lead to a chemical method which will appropriately measure the available form of zinc in soils. The method as outlined was used for acid soils and is not applicable to alkaline or calcareous soils.

Although the procedure is relatively simple, extreme care must he exercised in order to prevent contamination with zinc from reagents and equipment. Reagent grade chemicals were used and purification of water and sucrose was effected by an ion-exchange resin. An acid cleaning solution was the most effective method tried for removing traces of zinc from equipment. Sterilization of the soil to be assayed is not recommended.

The growth response of Aspergillus niger was related to known increments of zinc in 50-ml nutrient solution in 500-ml Erlenmeyer flasks. This relationship was used to evaluate the zinc status of soils. Florida soils known to respond to zinc fertilization ranged from 0.6 to 2.88 ppm zinc and Illinois soils ranged from 1.6 to 21.5 ppm zinc, according to the bio-assay. It is conceivable that a few Illinois soils may respond to zinc fertilization or are at least approaching a critical level.

¹ Contribution from the Department of Agronomy, University of Illinois, Urbana, Ill. Published with the approval of the Director. Work reported was supported in part by grants-in-aid from the Illinois Farm Supply Company and International Minerals & Chemical Corporation. Presented before Division IV, Soil Science Society of America, Cincinnati, Ohio, November 21, 1952.

² Assistant; Professor; and formerly Assistant in Agronomy, now Assistant Professor, Department of Agronomy, University of Delaware, Newark, Del.

Received for publication December 5, 1952.