Effect of grazing management on the maintenance of white clover

Abstract

The objectives of the project were to compare different cultivar types and methods to establish and maintain them in reseeded and permanent pastures as a basis for efficient low cost sheep production. In Ireland only 3% of pastures are reseeded annually and permanent pastures rarely contain more than 5% white clover. Improved clover content offers benefits of higher lamb growth rate and reduced fertiliser N use. Comparisons under cutting conditions provided no basis for replacement of Grasslands Huia by the new cultivar Aberherald. Grasslands Huia established successfully following direct reseeding and rotational grazing by sheep. It established more quickly than Kentish and gave higher yield only in the first year. A mixture of small and medium size white clovers should be sown for sheep grazing. Increasing seeding rate from 2 to 4 kg per ha increased pasture clover content only in the first year. Grasslands Huia persisted quite well for up to 5 years under rotational sheep grazing. It also survived under continuous grazing but leaf size was reduced. Rotational grazing management with sheep increased the clover content of permanent pasture from under 2% to 4% over 2 years. Highest clover yields were achieved with rest intervals of 20 to 28 days. Simulated mixed sheep and cattle rotational grazing on permanent pasture resulted in intermediate (10 to 12%) clover dry matter contributions to total dry matter compared with cattle (15 to 18%) and sheep (5 to 8%). Lamb growth rate was about 35% higher when the clover content of the sward was increased from very low to about 35%.