DRYIAND LUCERNE ESTABLISHMENT BY OVERDRILLING IN CENTRAL OTAGO

Abstract

Two field trials in semi-arid Central Otago compared lucerne establishment drilled in spring using five types of overdrilling equipment, with and without the use of glyphosate applied in early spring to control the resident vegetation. A cultivated treatment was included. The first trial, on a deep soil, gave 45-61% of viable seed establishing from overdrilling after herbicide application, similar to the cultivation treatment. Without herbicide establishment was 10-240/o. The second trial, on a shallow stony soil, gave very low (O-7%) establishment owing to inadequate control of sorrel by cultivation and herbicide and to the dry spring. Differences in drill performance were small. Keywords: lucerne. Medicago sativa L, brown grey earth, pasture improvement, overdrilling, cultivation, soil moisture, herbicide dessication. drill coulter.