Soil development under legume tree canopies

TitleSoil development under legume tree canopies
Publication TypeJournal Article
Year of Publication1986
AuthorsVirginia R.A
JournalForest Ecology and Management
Date Published1986
Call Number00348
Keywordsarticle, articles, Dalea,soil development, journal, journals, legume tree,soil development, nitrogen,soil, phosphorous,soil, Prosopis,soil development, soil development,legume trees, soil nutrients,nitrogen, soil nutrients,phosphorous
AbstractTree legumes influence soil development by altering the physical and chemical properties of the soil beneath the plant canopy. The accumulation of extractable NO3 and PO4 in soil beneath the Sonoran Desert woody legumes Prosopis glandulosa and Dalea spinosa was compared to soil from the tree interspaces. Measurements of natural 15N abundance indicate both these plants symbiotically fix N2 at the sites studied. Nutrient accumulation was related to the water regime of the site. High concentrations of symbiotically fixed N and P as NO3 and PO4 were found in the surface 60 cm of soil beneath a Prosopis stand utilizing groundwater. Relatively little NO3 or PO4 accumulated in the moist soil above the water table at 5 m. In contrast, NO3 and PO4 did not accumulate in the surface soil beneath Dalea growing in a sandy wash. Soil NO3 concentrations were lower beneath Dalea canopies than in the nonvegetated wash. The mechanisms by which tree legumes alter soil properties are reviewed. The direction and potential magnitude of soil changes in managed tree legume systems may be inferred from an understanding of the function of native plant-soil systems.