Nodulation of and nitrogen fixation by Lablab purpureus under field conditions

Abstract

The nodulation and growth of Lablab purpureus was studied at three sites on the far north coast of New South Wales. These sites were chosen to provide low, medium and high competition by naturalised rhizobia for the seed-borne inocula. The effect of seedbed preparation was studied at the low competition site. Maximum yield occurred with clean cultivation although response to inoculation was best in a rough seedbed or when sod sown. Additional lime improved legume growth when it was dependent on symbiotic nitrogen but had no effect with a clean seedbed. Effective strains CB1091 and CB1406 established poorly at the high and low competition sites respectively. Strain CB1024 established well at all sites and with the three different methods of seedbed preparation.