Comparison of tillage methods on red clover and ryegrass establishment and production under grazing in the establishment year

Abstract ‘Grasslands Pawera’ red clover ( Trifolium pratense L.) was drilled into perennial ryegrass ( Lolium perenne L.)‐white clover ( Trifolium repens L.)‐dominant pasture in autumn and spring. A prototype drill equipped with a chisel coulter and band spray mechanism was used. At both dates Pawera was drilled into a cultivated seed bed, oversown or overdrilled into an undisturbed sward, and overdrilled into paraquat‐sprayed bands. Effects of captan, phorate, methiocarb, and urea on red clover establishment were studied with autumn drilling. Spring drilling included blanket applications of paraquat and glyphosate and overdrilling of Pawera alone or with ‘Grasslands Nui’ perennial ryegrass. Sown plant survival and development, pasture production, and composition were evaluated under sheep grazing. After full cultivation, recovery of pasture production and red clover seedling development were more rapid for spring than autumn sowing. Compared to untreated pasture full cultivation reduced the establishment year yield by up to 43%, blanket herbicide by up to 41%, and band spraying by 14%. Drilling into a cultivated or blanket‐sprayed seed bed resulted in higher red clover plant numbers one year after sowing, and gave better red clover and ryegrass seedling development, especially for cultivation, than oversowing or overdriIIing into existing pasture. Band spraying improved red clover performance very little and pesticides and applied nitrogen had no important effects. Increases in red clover content caused by the tillage method were directly related to reductions in annual herbage yield.