Livestock farmers may be able to graze more cattle in less space while preserving soil structure through careful monitoring and management, work from the UK suggests.
The study, carried out at Rothamsted Research’s North Wyke Farm, compared the soil compaction after employing a ‘techno-grazing’ method, whereby larger groups of dairy beef steers were penned in relatively small areas (6 steers per hectare) and moved daily, to set-stocked grazing, the traditional lower-density approach (2.3 steers per hectare).
As well as measuring soil compaction over a season, researchers used GPS collars to monitor animals’ grazing patterns in the pasture, which was largely perennial ryegrass with 5% white clover.
They found that there was no significant difference in soil compaction between the two grazing approaches, nor in how the pasture recovered following the winter break. The movements of the animals were also similar, regardless of what grazing system they were part of.
A shift in land use
The idea of cell grazing is to make more efficient use of available land, growing more grass to harvest, which helps preserve soil structure in non-grazed areas. The success of the approach depends on regular movement of the cell-grazed cattle, as in the study.
“The results suggest that with careful management of cell grazing including appropriate stocking densities and resting periods, stocking rates on grassland could be increased with no detrimental consequences in soil structure beyond what would normally occur on grazed pasture. This means we can deliver more high-quality protein using the same land,” said Dr Alejandro Romero-Ruiz, who led the study.
Model behaviour
The team has developed a model which links grazing behaviour to soil structure and functions, which could have wider applications in analysis of the impact of grazing. One example could be to allow farmers to predict where the livestock deposit dung and urine — potential hotspots for greenhouse gas emissions.
GPS collars for livestock are a mature technology, though their use has grown in sophistication linked to new data analysis approaches. In recent years they have become increasingly popular, with some systems also serving as ‘virtual fencing’ by warning animals when they have moved outside certain zones and coaxing them to return to desired grazing areas.
