Overseeding benefits

Sector News28-6-2018

This year may see a greater need for overseeding following the long, wet spring. Overseeding is a cost-effective way to boost the production of a ley once the sward becomes open and weeds and unsown species start to invade. It maintains the productivity and quality of a sward beyone its expected life. 

To ensure the maximum benefit of overseeding, the exisiting ley still needs to contain a good proportion of  sown species. The process will be more successful if completed when a sward has just been cut or grazed, as this will reduce the competition to the new seed. Large grass varieties, such as tetrapoids, work best as they compete better with the existing grasses. 

Scarifying the field before drilling to remove thatch increases seed-to-soil contact and allows sunlight and moisture to reach the soil. Cross drilling can improve ground cover and rolling after drilling to increase soil-to-soil contact will also help to improve germination. 

Three-year-old leys can contain up to 30% weed grasses, which are lower yielding than perennial ryegrass by up to 1.4 tonnes of dry matter per hectare. Compared to perennial ryegrass, fertiliser efficiency is also much lower at between 17% and 42% for weed grasses. Overseeding trials have resulted in up to 40% more grass yield in the following year, as well as improving the nutritional quality of the ley.