INVESTIGADORES
ROUSSEAUX Maria Cecilia
artículos
Título:
Root length density and soil water distribution in drip-irrigated olive orchards in Argentina under arid conditions
Autor/es:
SEARLES, P.S; SARAVIA, D. A.; ROUSSEAUX, M. C.
Revista:
AUSTRALIAN JOURNAL OF AGRICULTURAL RESEARCH
Editorial:
CSIRO
Referencias:
Año: 2009 vol. 60 p. 280 - 288
ISSN:
0004-9409
Resumen:
A number of studies have evaluated many aboveground aspects of olive production, but essential root system characteristics have been little examined.  The objective of our study was to evaluate root length density (RLD) and root distribution relative to soil water content in three commercial orchards (northwest Argentina).  Depending on the orchard, the different drip emitter arrangements included either: 1) emitters spaced continuously at 1 m intervals along the drip line (CE-4; 4 emitters per tree); 2) 4 emitters per tree spaced at 1 m intervals, but with a space of 2 m between emitters of neighboring trees (E-4); or 3) 2 emitters per tree with 4 m between emitters of neighboring trees (E-2).  All of the orchards included either var. ‘Manzanilla fina’ or ‘Manzanilla reina’ trees (5-8 years-old) growing in sandy soils although the specific characteristics of each orchard differed.  Root length density values (2.5 – 3.5 cm/cm3) in the upper soil depth (0 – 0.5 m) were fairly uniform along the drip line in the continuous emitter (CE-4) orchard.  In contrast, roots were more concentrated in the E-4 and E-2 orchards in some cases with maximum RLD values of up to 7 cm/cm3.  Approximately, 70% of the root system was located in the upper 0.5 m of soil depth, and most of the roots were within 0.5 m of the drip line. For each of the three orchards, significant linear relationships between soil water content and RLD were detected based on 42 sampling positions that included various distances from the trunk and soil depths.  Values of RLD averaged over the entire rooting zone and total tree root length per leaf area for the three orchards were estimated to range from 0.19 to 0.48 cm/cm3 and from 1.8 to 3.5 km/m2, respectively.  These results should reduce the uncertainty associated with the magnitude of RLD values under drip irrigation as intensively-managed olive orchards continue to expand in established and new growing regions.