Cover crops for the Mediterranean rainfed fruticulture
Conference Paper
Overview
Research
Additional Document Info
View All
Overview
abstract
Cover cropping is the most desirable method of ground management in fruticulture.
However, in drought prone regions, such as in the Mediterranean basin, the
introduction of cover crops in the orchards should be done with caution due to
competition for water. The olive orchards are a paradoxical example. In spite of the
increase in the irrigated areas, most of the olive orchards are rainfed managed,
particularly in slopping lands with less access to water and irrigation infrastructures. In
this work, a summary of four year of research on cover cropping with self‐reseeding
annual legumes is presented. The groundcover percentage and the persistence of the
seeded species, their ability to produce biomass and to fix nitrogen from the
atmosphere and the effect of the covers on the tree nitrogen nutritional status and
olive yields were assessed. The results showed good soil coverage with living
vegetation during the winter and a mulch of dead material during the summer. The
seeded species dominated the cover during the four years of experience. The dry
matter yield (average of four growing seasons) ranged between 3 and 6 t/ha/year and
the nitrogen fixed in the above‐ground biomass between 50 and 115 kg/ha/year
depending on the length of the growing cycle. The lowest and highest values were
respectively recorded for Trifolium subterraneum cv. Nungarin and Trifolium
incarnatum cv. Contea. The early‐maturing cultivars produced less biomass and fixed
less nitrogen than midseason cultivars. A cover consisting of a mixture of early and
midseason species and cultivars of annual legumes produced an effect on the nitrogen
nutritional status and olive yield higher than the application of 60 kg N/ha/year.
