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Titolo:
In situ changes in gross N transformations in bare soil after addition of straw
Autore:
Recous, S; Aita, C; Mary, B;
Indirizzi:
INRA, Unite Agron, F-02007 Laon, France INRA Laon France F-02007INRA, Unite Agron, F-02007 Laon, France
Titolo Testata:
SOIL BIOLOGY & BIOCHEMISTRY
fascicolo: 1, volume: 31, anno: 1999,
pagine: 119 - 133
SICI:
0038-0717(199901)31:1<119:ISCIGN>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
NITROGEN MINERALIZATION; PLANT RESIDUES; MICROBIAL BIOMASS; ORGANIC-MATTER; POOL DILUTION; N-15; RATES; IMMOBILIZATION; CARBON; NITRIFICATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Recous, S INRA, Unite Agron, Rue F Christ, F-02007 Laon, France INRA Rue FChrist Laon France F-02007 ist, F-02007 Laon, France
Citazione:
S. Recous et al., "In situ changes in gross N transformations in bare soil after addition of straw", SOIL BIOL B, 31(1), 1999, pp. 119-133

Abstract

In situ N-15 techniques were used to quantify gross mineralisation, immobilisation and nitrification of N in bare soil nonamended and after incorporation of wheat straw (8 t ha(-1)). Experimental plots were confined within open-ended cylinders inserted into the tilled layer to 20 cm depth of a loamy soil (Typic Hapludalf). Measurements of gross N fluxes and C mineralisation were made during the year following incorporation of residues (September1993-October 1994). At each date of measurement, inorganic N was added to soil by multiple injections of (NH4NO3)-N-15-N-15 (atom % excess = 50.0) toa soil depth of 17.5 cm. The amount of NH4+ -N, NO3--N, organic N and their N-15 isotopic composition were determined 30 min after N-15 injections (t(0)), and 2-3 d after in situ incubation (t(1)). N transformation rates were estimated using a numerical model, Fluaz. In the nonamended soil, gross mineralisation in the 0-20 cm layer varied between 0.23 mg N kg(-1) soil d(-1) in December and 0.81 mg N kg(-1) soild(-1) in July. Immobilisation rate varied similarly and was about one-third of gross mineralisation. Gross fluxes corrected for the effects of soil temperature and water content, and expressed as a function of normalised time (day at 10 degrees C and optimal water potential) varied much less. The mean rate of gross mineralisation was0.42 mg N kg(-1) soil normalised d(-1), and for immobilisation it was 0.13mg N kg(-1) soil normalised d(-1), resulting in net mineralisation of 0.29mg N kg(-1) soil normalised d(-1). Gross mineralisation and immobilisationwere both increased by straw addition, with rates of 0.99 and 1.98 mg N kg(-1) soild(-1) respectively, observed for the first measurement in September, 7 d after incorporation. Immobilisation and mineralisation decreased steadily with time. One year after straw addition, gross immobilisation and mineralisation rates were similar to those measured in nonamended soil. This was consistent with the changes in rate of straw-C mineralisation and with the depletion of the coarse fraction in soil, determined in parallel. (C) 1998 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/11/20 alle ore 06:24:55