A gradient seeder for species establishment and production studies

Abstract

A gradient seeder, designed to produce a uniform change in seeding rate in proportion to the distance travelled, is described. A 'Grasslands' sodseeder was converted by attaching a male thread to the shaft operating the fluted seed flow mechanism and changing the drive system. From seed weights obtained at intervals along the gradient, calibration curves were constructed for vetch (Vicia satlva L.), subterranean clover (Trifolium subterraneum L.) and Glycine javanica L. A comparison was made between the conventional and gradient methods of studying the effect of seeding rate on the establishment of vetch and subterranean clover.