BIOMASS PRODUCTION AND CHANGES IN SOIL PRODUCTIVITY DURING LONG-TERM CULTIVATION OF PROSOPIS-JULIFLORA (SWARTZ) DC INOCULATED WITH VA MYCORRHIZA AND RHIZOBIUM SPP. IN A SEMIARID WASTELAND

The growth of Prosopis juliflora and its contribution to soil enrichme nt following inoculation with three vesicular-arbuscular isolates, Glo mus caledonius, Gigaspora calospora and an indigenous strain, and two Rhizobium isolates, P-5 and Tal-600, were assessed. The trees were 6 y ears old and grew on a semi-arid wasteland. There was a significant in crease in the biomass of closely spaced P., juliflora inoculated with G. caledonius alone, P. juliflora, growing on a relatively nutrient-de ficient wasteland, significantly restored the soil productivity by ame liorating and enriching the soil. A significant reduction in the soil reaction (pH) and a considerable improvement in soil organic carbon bu ild-up and phosphorus, at both depths. were observed in all the treatm ents by the end of the experiment. Moreover. although the total nitrog en content increased in comparison to controls, this increase was not statistically significant when comparisons were made between respectiv e treatments at the beginning of the experiment and after 6 years' gro wth.