INVESTIGADORES
CAVIGLIA Octavio Pedro
congresos y reuniones científicas
Título:
Carbon and Nitrogen Content in Aggregate Size Classes Under Continuous Cropped Maize
Autor/es:
NOVELLI, L. E.; MELCHIORI, R. J.; CAVIGLIA, O. P.
Lugar:
Pittsburgh, PA, USA
Reunión:
Congreso; ASA-CSSA-SSSA International Annual Meetings; 2009
Resumen:
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Although
high nitrogen fertilization in continuous cropped maize under NT system can
increase soil organic C and N concentration, the allocation of the elements in
different aggregate size has not been reported for our region. The effects of
long-term (13-yr) nitrogen fertilization of continuous cropped maize (Zea
mays L.) on aggregate size distribution and, aggregate organic C and N mass
were assessed on acuic Argiudolls at Parana, Argentina (31,5º S 60,3º W). The
experiment was conduced under NT with four nitrogen fertilization rates (0, 69,
138 y 276 kg
N ha- 1). Samples were taken at three soil depths (0-5,
5-10, 10-20 cm)
and wet sieved into three aggregate size classes (>2000, 250-2000, 53-250
µm). Proportion of aggregate in the sample, total C and N (%) and for each
aggregate size class was quantified. The proportion of >2000 µm aggregate
was higher in 0-5 cm
than in other depths. Nitrogen fertilization with 138 kg N ha- 1 increased
total N content (0-5 and 5-10
cm) and the C and N in >2000 µm aggregate size class
(0-5 cm).
Soil organic C (%) and C mass were unaffected by nitrogen fertilization in any
depth. The percentage of aggregates was strongly associated in the class >
2000 µm (0-5 and 5-10 cm).
Nitrogen after 13 year of continuous cropped maize not increased total C and N.
In spite of the fractionating sample in different aggregate size classes, there
was not a detectable effect of N on the C and N storage.