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Web URL(s): | http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2494.2004.00411.x/epdf Last checked: 10/02/2015 Requires: PDF Reader Access conditions: Item is within a limited-access website |
Publication Type:
| Refereed |
Author(s): | Farruggia, A.;
Gastal, F.;
Scholefield, D. |
Author Affiliation: | Farruggia: Institut de l'Elevage, Saint Genès Champanelle, France; Gastal: Unitè d'Ecophysiologie des Plantes Fourragéres, Lusignan, France; Scholefield: Institute of Grassland and Environmental Research, North Wyke Research Station, Okehampton, Devon, United Kingdom |
Title: | Assessment of the nitrogen status of grassland |
Source: | Grass and Forage Science. Vol. 59, No. 2, June 2004, p. 113-120. |
Publishing Information: | Oxford, Blackwell Scientific Publications |
# of Pages: | 8 |
Keywords: | TIC Keywords: Nitrogen; Grasslands; Measurement; Nutrition; Biomass; Soil management
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Abstract/Contents: | "Two types of diagnostics are used for N management in grasslands: diagnostics based on N concentration of shoots and diagnostics based on soil mineral N. The Nitrogen Nutrition Index (NNI) is an example of the first type. However, its evaluation requires the determination of shoot dry weight per unit area and, thus, constitutes a practical limit to its utilization in the context of farm studies. In order to simplify its evaluation, a method based on the N concentration of the upper sward layer (Nup) has been proposed. The objectives of this study were to test the relationship between NNI and Nup in the context of permanent grassland and to examine the relationship between Nup and soil mineral status. The study was conducted as two experiments, one on small cut-plots receiving contrasting rates of mineral N fertilization, and a second on plots of an existing field-scale lysimeter experiment. In each plot and at several dates, shoot biomass within quadrats was measured, N concentration was determined on the upper leaves and on the entire shoots, and mineral nitrogen of the soil below the vegetation sampled was determined. N concentration of the upper lamina layer of the canopy was linearly related to the NNI determined on the entire shoots. Therefore, determining N concentration in leaves at the top of canopy appears to be an alternative means to evaluate NNI without having to measure shoot biomass. The absence of an overall significant correlation between soil mineral N content and sward N index, observed over the two studies, indicates that each of these two indicators has to be considered specifically in relation to the objective of the diagnositc procedure. As sward N index may vary independently of soil mineral content, the sward N indicator does not appear to be a suitable indicator for diagnosis of environmental risks related to nitrate leaching. However, soil mineral N content does not allow the prediction of sward N status and thus is not a suitable indicator of sward growth rate. Although soil mineral N content is an important environmental indicator for nitrate-leaching risks during potential drainage periods, it has a limited diagnosis value with repect to the herbage production function of grasslands." |
Language: | English |
References: | 27 |
Note: | Tables Graphs |
| ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete): Farruggia, A., F. Gastal, and D. Scholefield. 2004. Assessment of the nitrogen status of grassland. Grass Forage Sci. 59(2):p. 113-120. |
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| Web URL(s): http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2494.2004.00411.x/epdf Last checked: 10/02/2015 Requires: PDF Reader Access conditions: Item is within a limited-access website |
| MSU catalog number: SB 197 .B7 |
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