Autumn establishment of lucerne (Medicago sativa L.) inoculated with four different carriers of Ensifer meliloti at four sowing dates

Abstract

The effects of autumn sowing dates (26 January 2012, 21 February 2012, 15 March 2012, 3 April 2012) and inoculant carriers (ALOSCA®, coated seed, Nodulator® and peat slurry) on lucerne (Medicago sativa L.) establishment and yield were studied at Lincoln University on a variable Templeton silt loam soil. For the 2012/13 regrowth season the January (14.7 t/ha) sowing date yielded more dry matter (DM) than the March (11.2 t/ha) and April (7.3 t/ha) sowing dates, and February (13.2 t/ha) was intermediate. All four inoculation carriers resulted in increased DM and nitrogen (N) yields compared with the bare seed control. A comparison of the peat inoculated and bare seed treatments indicated an extra 335 kg N/ha was removed in herbage from the inoculated treatments. Results highlight the importance of rhizobia, biological nitrogen fixation, and seed inoculation when sowing lucerne into soil with no paddock history of lucerne. Keywords: alfalfa, ALOSCA®, bare seed, biological nitrogen fixation, coated seed Nodulator®, peat slurry treated seed, rhizobia.