Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): J. L. Sims; B. G. Blackmon
    Date: 1967
    Source: Soil Science Society of America Proceedings 31(5):676-680
    Publication Series: Scientific Journal (JRNL)
    Station: Southern Research Station
    PDF: Download Publication  (3.24 MB)


    Soil test method s that measure NH4+-N in silt 100ms before and after incubation under waterlogged conditions were evaluated as predictors of N availability to 'Nato' rice (Oriza sativa L.) frown in the greenhouse. Eighteen soils for each of five previous year crop histories were utilized. An soils were from crop rotations containing rice. Coefficients of determination (r²) for the regression of N uptake by rice on NH4+-N after 6 days incubation of soil from the different crop histories increased in the order of cotton (Gossypium hirsutum L.) < rice < lespedeza (Lespedeza striata Thumb.) < soybean (Glyeine mas L.) < reservoir (irrigation water storage or fish production), and ranged from .12 to. 77. Exchangeable Ca was inversely related to N uptake and accounted for significant percentages of variation in uptake on all soils except those from reservoirs. Exchangeable Ca was not related to NH4+ -N production during incubation. For all previous year crop histories NH4 -N in soil after 6 days incubation was a better single predictor of N uptake by rice than soil organic matter values. lnitial NH4+ -N content of reservoir soils was about 5 times greater than in soils of other crop histories. The amount in these silt loam soils from reservoirs (55 kg N/ha) was about half that found in previous studies for reservoir soils of clay texture. Multiple regression analyses indicated that including initial NH4+ -N together with NH4+ -N production during incubation Improved the prediction of N uptake over NH4 -N production values alone. Including exchangeable Ca together with initial NH4+ -N and NH4+ -N production values improved the prediction on all soils except those from reservoirs.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Sims, J. L.; Blackmon, B. G. 1967. Predicting Nitrogen Availability to Rice: II. Assessing Available Nitrogen in Silt Loams With Different Previous Year Crop History. Soil Science Society of America Proceedings 31(5):676-680.


    soil organic matter, ammonium

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page