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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Hue, N. V. Search for Related Content PubMed Articles by Hue, N. V. Agricola Articles by Hue, N. V.

A Possible Mechanism for Manganese Phytotoxicity in Hawaii Soils Amended with a Low-Manganese Sewage Sludge

Department of Agronomy and Soil Science, Univ. of Hawaii at Manoa, 1910 East-West Road, Honolulu, HI 96822.

^* Corresponding author.

ABSTRACT

Knowledge of sludge-soil interactions is essential for successful utilization of sludges on agricultural lands. To obtain such information, a greenhouse experiment was conducted on three Hawaii soils: a Typic Hydrandept, a Typic Chromustert, and a manganiferous Tropeptic Eutrustox. Each soil received four rates (0, 20, 40, and 80 g kg^–1) of a low-Mn municipal sludge. Lettuce (Lactuca saliva L.) was grown as a test crop. Manganese phytotoxicity unexpectedly occurred in all sludge-amended treatments of the Oxisol and in the 80 g kg^–1 rate of the Vertisol as indicated by reduced dry matter yields and by high plant-Mn concentrations, which were all greater than 1000 mg Mn kg^–1. Soil-solution Mn also increased, reflecting the problem. In the manganiferous Oxisol, where Mn toxicity was most serious, soil-solution Mn at transplanting significantly increased from 0.02 to 0.46, 5.57, and 7.26 mg Mn L^–1 as sludge rate increased from 0 to 20, 40, and 80 g kg^–1, despite a concurrent increase in soil pH from 5.43 to 6.78, 7.91, and 8.10. Four weeks later (at harvest), soluble Mn increased even more drastically from 0.01 in the untreated soil to 57, 640, and 1160 mg Mn L^–1 in the 20, 40, and 80 g kg^–1 sludge rate, even though soil pH levels of all sludge treatments were essentially equal (pH 5.0). These facts were virtually inexplainable by soil pH, redox conditions or the direct Mn contribution from the sludge. In contrast, Mn complexation by organic ligands (e.g., tartaric, pyruvic, protocatechuic acids), which were found in considerable quantities in the soil solutions of sludge-amended soils, accounted for 76 to 99% of the soluble Mn, and adequately explained the high and phytotoxic levels of Mn in soil solutions.

Contribution from Dep. of Agronomy and Soil Science, College of Tropical Agric. and Human Resour., Univ. of Hawaii, Honolulu. Journal Series no. 3184 of the Hawaii Inst. of Tropical Agric. and Human Resour.

Received for publication June 25, 1987.

This article has been cited by other articles:

				N. V. Hue, S. Vega, and J. A. Silva Manganese Toxicity in a Hawaiian Oxisol Affected by Soil pH and Organic Amendments Soil Sci. Soc. Am. J., January 1, 2001; 65(1): 153 - 160. [Abstract] [Full Text]