Intercropping system of tropical leguminous species and Eucalyptus camaldulensis, inoculated with rhizobia and/or mycorrhizal fungi in semiarid Brazil

Abstract

For the purpose of reforestation and wood supply the leguminous tree Anadenanthera peregrina, a native species, was intercropped with Eucalyptus camaldulensis in a degraded semiarid area of Brazil. Single and mixed stands of these species were inoculated with Rhizobium and/or arbuscular mycorrhizal fungi (AMF). The growth of all species in mixed stands did not differ from those cultivated in monoculture and land equivalent ratio (LER) exceeded unity in intercropped plots. Inoculated plants showed greater height and diameter growth and dry matter and nutrient concentration in plants of A. peregrina was higher in inoculated single plots. The distribution, composition and density of AMF species was related to the rhizosphere effect of plant species. The intercropped model where all the plants were inoculated achieved soil AMF diversity patterns similar to those of the preserved area and showed also higher soil organic matter, nutrient content as well as a reduction in soil macroporosity. This model of intercropping may be considered as an efficient system for reforestation under semiarid conditions.

Mycorrhizal Interactions for Reforestation: Constraints to Dryland Agroforest in Brazil

“…The inoculated native species P. reticulata and A. peregrina showed higher height and diameter growth when mixed with E. camaldulensis [2,3]. The double inoculation of legumes improved dry matter production and nutrient content, showing that the productivity of inoculated agroforestry systems was greater than that of uninoculated ones, especially regarding aboveground biomass and basal area.…”

“…Scarce reports on recommended AM species for reforestation [44] mentioned four species (Entrophospora colombiana, Glomus etunicatum, G. clarum, and Scutellospora pellucida) for reforestation in southern Brazil. Our studies lead us to suggest the use of a mixed (Acaulospora, Glomus, and Gigaspora) inoculum according to our research in dry forests [2,3,18,19].…”

“…Legume species, chosen to increase the input of N, were interplanted with a second nonlegume species, and with a species of Eucalyptus that tolerates dry conditions (E. camaldulensis) and can be a source of wood for local community use (E. grandis). Details of the original experimental design, sampling, and results are provided by Pagano et al [2,3,18]; we present below a discussion of findings from Brazilian dry forest necessary to place in perspective the importance of reforestation for the present review. Our experimental results provide land managers with information on the AMF occurrence and productivity of the vegetal species tested, which were inoculated with AMF and rhizobia (for legumes), corroborating the use of dual inoculation to improve legume production.…”

“…The following observations were made on naturally regenerating woody Caatinga (remaining of dry deciduous forest), disturbed and reforested sites at the semiarid of Minas Gerais, during 2004-2006. The area was described in Pagano [110] and Pagano et al [2,3,102].…”

“…Several reports on reforestation/afforestation have showed that alternatives to current agricultural practices have resulted in an enhanced interest in agroforestry systems; moreover, reforestation provides restoration of forest ecosystem goods and services, including improved soil fertility and soil structure, which often leads to increased productivity and/or sustainability of the systems [1][2][3].…”