Manage Compaction to Prevent Water Pollution

– Anglia Farmer

Farmers and contractors are reminded to manage soil compaction and pesticide applications carefully in an effort to prevent water pollution.

Adhering to pesticide restrictions and measures such as buffer zones and application timings are important measures, says Hutchinsons agronomist Jess Farrant. Growers should also manage the use of tramlines, gateways and pathways to reduce compaction.

“Compaction produces a layer of soil within the [soil] profile which does not allow for the percolation of water,” says Ms Farrant. “This means the infiltration of water into the soil takes longer and the volume of surface run-off is increased.”

Run-off can carry pesticides overland and into water sources, not only causing pollution, but also reducing the efficacy of residual chemistry. But growers should not only consider tramlines and other areas of heavy traffic as areas where compaction may be a concern.

“Larger farms, less labour and machinery that lets us work fields all year around, have resulted in a culture of increasing and unnecessary cultivations – all of which lends itself to poor soil structure and health – compaction can be found anywhere in the field.”

Hutchinsons measures compaction by carrying out Healthy Soils assessments in the field. The physical aspect of these checks identifies any structural issues within the soil. But it is important that assessments are carried out at the right time.

Rather than the summer, when soils are generally dry, the best time to assess soil health is during the wetter months. This is when the soils are moist and biologically active, allowing for worm numbers to be measured, says Ms Farrant.

Ignore soil at your peril, she adds. “Compaction will increase run-off and decrease rooting ability of crops, increased run-off may result in pesticide residues being found in water and will also decrease the efficacy of residual herbicides.”