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Titolo:
Use of N-15-labeled soil in measuring nitrogen fertilizer recovery efficiency in transplanted rice
Autore:
Bronson, KF; Hussain, F; Pasuquin, E; Ladha, JK;
Indirizzi:
Texas A&M Univ, Texas Agr Expt Stn, Lubbock, TX 79401 USA Texas A&M Univ Lubbock TX USA 79401 s Agr Expt Stn, Lubbock, TX 79401 USA Natl Agr Res Ctr, Land Resources Inst, Islamabad, Pakistan Natl Agr Res Ctr Islamabad Pakistan Resources Inst, Islamabad, Pakistan Int Rice Res Inst, Soli & Water Sci Div, Manila 1099, Philippines Int RiceRes Inst Manila Philippines 1099 Div, Manila 1099, Philippines
Titolo Testata:
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL
fascicolo: 1, volume: 64, anno: 2000,
pagine: 235 - 239
SICI:
0361-5995(200001/02)64:1<235:UONSIM>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
FIELD EXPERIMENTS; LABELED NITROGEN; IRRIGATED RICE; N-15 BALANCE; FLOODED RICE; FATE; EXTRACTS; PLANTS; WHEAT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
30
Recensione:
Indirizzi per estratti:
Indirizzo: Bronson, KF Texas A&M Univ, Texas Agr Expt Stn, Route 3,Box 219, Lubbock, TX 79401 USA Texas A&M Univ Route 3,Box 219 Lubbock TX USA 79401 79401 USA
Citazione:
K.F. Bronson et al., "Use of N-15-labeled soil in measuring nitrogen fertilizer recovery efficiency in transplanted rice", SOIL SCI SO, 64(1), 2000, pp. 235-239

Abstract

In transplanted flooded rice (Oryza sativa L,) culture in Asia, N fertilizer recovery efficiency (RE) estimates are usually greater with the difference method than with the N-15 method. These reported differences are greaterand more common for transplanted irrigated rice than for upland crops and might be associated with basal N applications when plant demand is low. Added N interactions (ANI), or greater soil N accumulation in fertilized plants than in unfertilized plants, are often cited as the reason for these differences. The clauses of ANI can be stimulation of mineralization of soil organic matter by fertilizer or greater root exploration in fertilized plants. The objectives of this pot study were (i) to compare the N-15 dilution method using enriched N-15-urea (5.0 atom %), and N-14-urea (0.366 atom %) plus N-15-labeled (0.447 atom %, Maahas clay [isohyperthermic Andaqueptic Haplaquoll]) soil with the difference method of measuring RE of N, as affectedby timing of application, and (ii) to use N-15-labeled (0.447 atom %) soilto directly measure ANI as N-15 accumulation in N-14 fertilized pots minusN-15 accumulation in unfertilized pots, Recovery efficiency measures at physiological maturity were higher with the difference method (54%) than withthe two isotope dilution methods (44%), which were in turn similar. The real ANI measured was negligible, as the root biomass in this clay soil was not greatly affected by fertilization. Therefore, the ANI was apparent and due to isotope substitution. The RE estimate by difference (54.4%) was therefore more accurate than the RE measure by N-15 methods (44.4%). The 33.2% of added N-15 not accounted for in the plant-soil system was a measure of N fertilizer losses (NH3 volatilization from floodwater, denitrification, NH3loss through the plant during grain fill) that were not affected by isotope substitution. Recovery efficiency estimated with N-15-enriched soil plus ordinary urea was identical to the RE estimate using enriched N-15-urea, although both were underestimations because of isotope substitution.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 12:19:12