HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Mangiafico, S. S. Articles by Guillard, K. Search for Related Content PubMed Articles by Mangiafico, S. S. Articles by Guillard, K. Agricola Articles by Mangiafico, S. S. Articles by Guillard, K. Related Collections Nitrogen Turfgrass Nutrient Management

Anion Exchange Membrane Soil Nitrate Predicts Turfgrass Color and Yield

Dep. of Plant Science, Unit 4067, University of Connecticut, 1376 Storrs Road, Storrs, CT 06269-4067

View larger version (47K): [in a new window]   Fig. 1. Mean light reflectance measurements and clipping yield from turfgrass in relation to mean soil NO3–N desorbed from in situ anion exchange membranes. All measurements were averaged from 23 dates across two growing seasons. A fitted Mitscherlich-Bray model is shown for each plot.

View larger version (60K): [in a new window]   Fig. 2. Light reflectance measurements from the Spectrum CM1000 reflectance meter plotted against soil NO3–N desorbed from in situ anion exchange membranes, for each sample date. Significant (p < 0.05) linear plateau models are shown for dates on which such models were found. Vertical lines to the x-axes indicate critical value of soil NO3–N. Scale of x-axes varies among plots.

View larger version (19K): [in a new window]   Fig. 3. Plot of cumulative frequency of critical values of soil NO3–N from linear plateau models. Critical values were pooled across five light reflectance measurements and clipping yield measurements and across all dates on which significant linear plateau models were found. Dashed lines indicate cumulative frequencies of 50, 80, and 90% and their respective critical values.

View larger version (56K): [in a new window]   Fig. 4. Cate-Nelson models of relative light reflectance measurements and relative clipping yield for turfgrass in relation to soil NO3–N desorbed from in situ anion exchange membranes. Relative reflectance and yield values are expressed as a fraction of plateau values for reflectance or yield for each sample date. Vertical lines to the x-axes represent critical x values which divide data into two populations, one which has a high probability of response to higher soil NO3–N values and one which has a low probability of response. Horizontal lines minimize data in quadrants I and II. Error I indicates the percentage of observations in quadrant I and represents an overprediction of the critical x value. Error II indicates the percentage of observations in quadrant II and represents an underprediction of the critical x value. Data are pooled from 23 dates across two growing seasons. Number of observations for each plot is given by n.

View larger version (25K): [in a new window]   Fig. 5. Mean soil NO3–N desorbed from in situ anion exchange membranes in relation to N application rate for a mixed cool-season turf lawn grown on a fine sandy loam soil in Connecticut. Soil NO3–N values were averaged by treatment from 23 dates across two growing seasons. N was applied in 6 mo each growing season, May through October, for a total of between 0 and 587 kg ha–1 yr–1 A fitted model consisting of an exponential curve segment and a linear segment is shown.