Effect of Rhizohnim melilotti and VA-mycorrhizac on Forage Yield and Quality of Two Alfalfa Cultivars

Abstract

An experiment was conducted at the Demonstration Farm of the faculty of Agriculture, University of Khartoum at Shambat during the period December 1997 to June, 1999, to investigate the effect of Rhizobium meliloti and VA-mycorrhizae on growth, forage yield and quality of two alfalfa cultivars (local Hegazi and imported Pioneer 5929). The treatments consisted of inoculation with Rhizobium melilotti, VA-mycorrhizae, and (VAM+R) in addition to a reference control. A split- plot design with three replications was used in which the two alfalfa cultivars were assigned to the main plots and the microorganisms to the sub-plot treatments. Rhizobium melilotti, VA-mycorrhizae, and their combinations significantly improved growth parameters, which were reflected in higher yields of good quality forage. Rhizobium melilotti increased forage fresh yields by 42%, whereas the increments in forage fresh yields by VAM alone and VAM+R were 60 % and 65%, respectively. The forage nutritive value was improved by Rhizobia inoculation in the winter samples by 26.9% for the crude protein and by 32.3% for phosphorus content. Corresponding increments for the joint effect of VAM+R were 23.2% for crude protein and 36.1% for phosphorus compared to the control. The local cultivar Hegazi outscored the introduced Pioneer in the growth parameters which were reflected in higher forage yield of good quality compared to the introduced one. It produced 25.7% more protein than the Pioneer variety.