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 Thompson, T. L. Articles by Blackmer, A. M. Search for Related Content PubMed Articles by Thompson, T. L. Articles by Blackmer, A. M. Agricola Articles by Thompson, T. L. Articles by Blackmer, A. M.

Quantity-Intensity Relationships of Soil Ammonia in Long-Term Rotation Plots

Dep. of Soil and Water Science, Univ. of Arizona, Tucson, AZ 85721

A. M. Blackmer^*

Dep. of Agronomy, Iowa State Univ., Ames, Iowa 50011

* Corresponding author.

ABSTRACT

Reports of release of nonexchangeable NH⁺₄ from soils under some conditions and reports that management practices can change the affinity of the exchange complex for NH⁺₄ indicate a need to reevaluate the commonly accepted practice of determining exchangeable NH⁺₄ to assess the availability of NH⁺₄ to plants. To address this need, quantity-intensity (Q/I) relationships were studied in soil samples from two Iowa soils, a Webster clay loam (fine-loamy, mixed, mesic Typic Haplaquoll) and a Galva silty clay loam (fine-silty, mixed, mesic Typic Hapludoll) in long-term experiments having various crop-rotation and N-fertilizer treatments. The observed Q/I relationships gave no evidence for release of nonexchangeable NH⁺₄. Potassium-exchangeable NH⁺₄ concentrations were well correlated with measurements of labile NH⁺₄ (r = 0.91, P < 0.01) and equilibrium activity ratios for NH⁺₄ (r = 0.89, P < 0.01). No significant relationship was found between relative affinity of the exchange complex for NH⁺₄ and organic C within each soil. Soil management practices influenced NH⁺₄ availability as evaluated by KCl-exchangeable NH⁺₄ and Q/I parameters, but did not change the relative affinity of the exchange complex for NH⁺₄. Overall, indexes of NH⁺₄ availability based on determinations of K-exchangeable NH⁺₄ were similar to those derived from studies of Q/I relationships.

Contribution of the Iowa Agric. and Home Economics Exp. Stn., Ames. Project no. 2995. Journal Paper no. J-14446. This work was supported in part by the Integrated Farm Management Demonstration Program of the Agricultural Energy Management Fund, state of Iowa, through the Iowa Dep. of Agriculture and Land Stewardship.

Received for publication April 12, 1991.

This article has been cited by other articles:

				W. A. R. N. Fernando, K. Xia, and C. W. Rice Sorption and Desorption of Ammonium from Liquid Swine Waste in Soils Soil Sci. Soc. Am. J., June 2, 2005; 69(4): 1057 - 1065. [Abstract] [Full Text] [PDF]

				F.L. Wang and A.K. Alva Ammonium Adsorption and Desorption in Sandy Soils Soil Sci. Soc. Am. J., September 1, 2000; 64(5): 1669 - 1674. [Abstract] [Full Text]