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 Kirkham, M. B. Search for Related Content PubMed Articles by Kirkham, M. B. Agricola Articles by Kirkham, M. B.

Characteristics of Wheat Grown with Sewage Sludge Placed at Different Soil Depths¹

ABSTRACT

This study was done to determine the effect on plant growth and elemental uptake when sludge was applied in a layer below the surface rather than on the surface. Sludge was placed at different depths in columns of a clay loam soil (Udertic Paleustolls). Winter wheat (Triticum aestivum L. em. Thell. ‘Ponca’) was grown in the columns.

When sludge was placed at the 0- to 2-cm depth (surface application), dry weight of shoots was 2.4 times more than when sludge was placed at the 18- to 20-cm depth. Root growth was prolific in the vicinity of sludge layers at the 18- to 20-cm depth, but total root weight in columns was about the same with sludge placed at either depth. Soil water content was lower in columns with better plant growth, probably because of greater transpiration. Dilute-acid (0.05N HCl + 0.25N H₂SO₄) extractable concentrations of heavy metals (Zn, Cu, Cd) in soil were lower when sludge was at the 18- to 20-cm depth than when sludge was at the 0- to 2-cm depth. Concentrations of Cu and Cd were highest in shoots of plants in columns with surface-applied sludge. Highest concentrations of Cu and Cd in the roots occurred when sludge was at the 18- to 20-cm depth rather than at the surface. Relatively small concentrations of Cu and Cd in roots were transferred to the shoots. The results showed that for maximum dry matter production, sludge should be surface-applied. For minimal transfer of heavy metals from roots to shoots, sludge should be layered below the surface of the soil.

Key Words: heavy metals • soil water content • zinc • copper • cadmium • Triticum aestivum L. em. Thell.

¹ Journal Article 3598 of the Agric. Exp. Stn., Oklahoma State Univ., Stillwater, OK 74074. Partial support for work was provided by Natl. Sci. Found., Problem Focussed Research Applications, Grant no. NSF ENV77-04092. The conclusions reached and opinions expressed in this report are those of the author and do not represent those of the Natl. Sci. Found. nor any other branch of the federal government.

² Assistant Professor, Dep. of Agronomy, Oklahoma State Univ., Stillwater, OK 74074.

Received for publication January 27, 1979.