ABSTRACT

The effects of land imprinting on soil moisture, germination, seedling survival and biomass production of some grasses and legumes interseeded into arid land ecosystems were studied at two experimental sites in Tucson and near Oracle Arizona from July 1983 to October 1985. Three plant cover treatments including grasses, legumes and a grass-legume mix combined with four surface treatments imprinted, mulched, imprinted-mulched, and an untreated surface were imposed at two sandy loam sites. The Oracle site received natural rainfall only, whereas the dried Tucson site received supplemental irrigation in addition to rainfall in amounts equal to the rainfall differences. Imprinting increased soil moisture over the untreated surface by 33% at Oracle and by 54% at Tucson. At Oracle, grass seedling emergence was increased by 126% over the untreated surface and by 87% over the mulch treatment; while legume emergence was increased by 80% and 367%. Imprinting produced similar increases in grass and legume emergence at the lower elevation. Significant increases (P < 0.05) in biomass production as a result of land imprinting were also recorded at both sites. At Oracle the imprinted surface increased biomass production by 102% over the untreated and by 35% over the mulched surface. At Tucson, the increases in biomass production were 63% over the untreated surface and 333% over the mulched surface; however mulching produced more biomass than the untreated surface. These results suggest that land imprinting is an effective technique in interseeding grass and legumes species and increasing productivity in arid environments where precipitation is limited.