Controlling Soil Compaction in Grasslands through Controlled Traffic Farming

Soil compaction is a serious problem globally with 20% of arable land at risk from compaction in regions for food production. Compaction can affect intensive grasslands. Damaging the structure of the soil of grassland through compaction can reduce dry matter yield by 14% from tractor compaction after 3 years. One method of reducing soil compaction in grassland production is with controlled traffic (CT), which involves restricting the movement of agricultural machinery to set areas of a field. Global Navigation Satellite System (GNSS) was used to track all traffic across two grass silage fields in south-west Scotland over 3 years: one with CT and the other with normal traffic (NT). The fields were sown with 50/50 perennial ryegrass/red clover and monitored for dry matter (DM) yield. Yields were compared within each field as strips with Nil nitrogen (N), Moderate N and High N. CT gave greater dry matter yield for all the N treatments and years than NT. Increases were 7.0% for Nil N treatment, 8.2% for Moderate N treatment and 9.3% for High N over 3 years. The soil structure was better across the CT field than the NT field with more earthworms; however, soil organic matter (SOM) was not affected.