Spectral estimates of the absorbed photosynthetically active radiation and light-use efficiency of a winter wheat crop subjected to nitrogen and water deficiencies
| Autor: | Frédéric Baret, Martine Guerif, Silvio Steinmetz, R. Delecolle |
|---|---|
| Přispěvatelé: | Unité de bioclimatologie, Institut National de la Recherche Agronomique (INRA), ProdInra, Migration |
| Jazyk: | angličtina |
| Rok vydání: | 1990 |
| Předmět: |
Canopy
Irrigation 010504 meteorology & atmospheric sciences [SDV]Life Sciences [q-bio] Estimates of the absorbed chemistry.chemical_element RAYONNEMENT PAR 01 natural sciences Crop Anthesis ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences 2. Zero hunger Phenology fungi food and beverages 04 agricultural and veterinary sciences 15. Life on land Nitrogen [SDV] Life Sciences [q-bio] Agronomy chemistry Photosynthetically active radiation 040103 agronomy & agriculture 0401 agriculture forestry and fisheries General Earth and Planetary Sciences Environmental science Interception |
| Zdroj: | International Journal of Remote Sensing International Journal of Remote Sensing, Taylor & Francis, 1990, 11 (10), pp.1797-1808 Applications of remote sensing in agriculture Applications of remote sensing in agriculture, Apr 1989, Nottingham, United Kingdom Repositório de Informação Tecnológica da Embrapa (Infoteca-e) Empresa Brasileira de Pesquisa Agropecuária (Embrapa) instacron:EMBRAPA |
| ISSN: | 0143-1161 1366-5901 |
| Popis: | A linear regression equation is found relating the photosynthetically active radiation intercepted by the canopy (PARi), measured with hemispherical photographs, and both the normalized difference ND and the ratio NIR/R vegetation indices. On the basis of this equation, NIR/R is used to estimate PARi during the crop cycle. The efficiency with which the PAR absorbed by the crop is transformed into biomass (ϵc) is calculated for three phenological phases of the crop. Nitrogen fertilization is the main factor affecting light interception. At the booting stage, PARi is about 15 per cent greater for treatments with higher nitrogen levels. ϵc is influenced by both nitrogen and irrigation levels, and varies with the phenological phases of the crop. For the irrigated plots, ϵc is higher in the period going from anthesis to soft dough and not in the period from stem elongation to anthesis as most published results indicate. Water stress is the main factor affecting ϵc. The greatest reductions of ;ϵc are o... |
| Databáze: | OpenAIRE |
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