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 Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Ma, B. L. Articles by Costa, C. Search for Related Content PubMed Articles by Ma, B. L. Articles by Costa, C. Agricola Articles by Ma, B. L. Articles by Costa, C. Related Collections Nitrogen Maize Nutrient Management Plant Nutrition Soil Fertility and Productivity Maize Management

Comparison of Crop-Based Indicators with Soil Nitrate Test for Corn Nitrogen Requirement

^a Eastern Cereal and Oilseed Res. Cent. (ECORC), Cent. Exp. Farm, Res. Branch, Agric. and Agri-Food Canada, 960 Carling Ave., Ottawa, ON, Canada, K1A 0C6
^b Univ. of Paso Fundo, Paso Fundo, RS, 99001-970, Brazil

View larger version (27K): [in a new window]   Fig. 1. Monthly total precipitation (mm) during the growing seasons of 2000, 2001, and 2002 (May to September) compared with the 42-yr (1961–2002) average precipitation at the Central Experiment Farm, Ottawa.

View larger version (32K): [in a new window]   Fig. 2. Differentiation of preplant N effects by leaf chlorophyll meter (SPAD) and canopy reflectance [normalized difference vegetation index (NDVI)] measured at V6. The bars followed by different letters indicate significant differences (P 0.05).

View larger version (23K): [in a new window]   Fig. 3. Effect of preplant N treatments on whole-plant N concentrations of two hybrids at V6 growth stage in 2001 and 2002. The bars followed by different letters indicate significant differences (P 0.05).

View larger version (12K): [in a new window]   Fig. 4. Effect of preplant N treatments on the soil NO3–N at V6 growth stage for 2000, 2001, and 2002. Error bars associated with each data point indicate spatial variability in soil NO3–N.

View larger version (48K): [in a new window]   Fig. 5. Effect of different N treatments on corn grain yield (Mg ha–1) in 3 yrs. The bars labeled with the same letter are not statistically significant at P 0.05 within each year. The N treatments are 0, 40, 80, 120, 250, 0 + 80, 40 + 40, and 40 + 160 kg N ha–1. The first five N treatments are preplant applications, and the last three treatments are combinations of preplant and sidedress applications.

View larger version (28K): [in a new window]   Fig. 6. Effect of different N treatments on the total N uptake in stover and grain at maturity in 3 yr. The values in the bars represent kg N ha–1. The bars following with the same letter are not significant at P 0.05 for the total N uptake (i.e., stover + grain N). The LSD values are 12.6, 6.4, and 8.9 kg N ha–1, respectively, for stover N in 2000, 2001, and 2002, and 13.9, 11.9, and 18.1 kg N ha–1, respectively, for grain N in 2000, 2001, and 2002.