27 February 1998

Curb traffic on grass fields

SOILS need air spaces for drainage and nutrient exchange, so why roll down grass fields in spring?

So asks Axient consultant Neil Adams, who cites SAC trials to show that first cut silage yields and proteins increase when traffic on grass fields is minimised.

"With the exception of fertiliser applications, there is no need to have any machinery in fields prior to first cut."

Rollers are heavier and narrower than fertiliser spreaders, requiring more tractor passes to cover the entire field, explains Mr Adams. Tractor wheels exert more pressure than the roller, and can obliterate 25% of the area rolled.

He believes many fields are rolled because it has become an annual ritual and although rolling is inexpensive, he suggests considering the objectives and benefits before going ahead.

Fields may benefit from rolling when it is essential to push down stones which may damage machinery, or to create better plant/soil contact in puffy soils, after frost heave, or bad poaching.

"But walk around before you roll, and check for areas that need rolling. Then use a wide set of rollers, or gang, to minimise tractor wheelings. Also reduce tyre pressures to reduce tyre stress, or use dual wheels or floatation tyres."

"When rolling is causing rutting stop as it will make silaging harder, not easier," says Mr Adams.

ROLLING GRASS

&#8226 Unnecessary expense.

&#8226 Reduces air spaces in soil.

&#8226 Impedes drainage.