Early start to grass sowing

Poor consolidation at drilling means grass seed germination is leaving bare earth for weeds to colonise.

Livestock farmers across England and Wales have been out earlier than usual drilling new grass leys this year, taking advantage of the kind winter weather and keen to make up the forage shortfall caused by last summer’s drought. Grass is usually reseeded from mid-March onwards.

“Soil temperatures taken in the south west recently have been at 8°C, which is plenty warm enough for grass seed to germinate,” says Oliver Seeds general manager, Rod Bonshor.

“Clover may struggle when drilled this early, but species such as perennial ryegrasses, festuloliums and Timothy will all get going pretty well. It’s a case of throw away the calendar and go when the land is fit to sow and moisture is available.”

Lighter, sandier soils will be able to take early drillings better than colder, damper clay soils, so Mr Bonshor advises farmers on heavier land to hold back a week or two.

“The same old rules apply when reseeding whatever time of the year it is being done,” warns Mr Bonshor. “Do soil tests to make sure there are enough nutrients available and dig a soil pit to check for compaction. Check the field drains are working and assess how many weeds are growing and if they need treating.

“Work the soil down to a fine, firm seedbed and roll with a Cambridge roll to consolidate the surface before drilling or broadcasting the seed, and then roll again.”

Weedy autumn reseeds

While soil testing this spring, Mr Bonshor has noted how erratic plant establishment has been in autumn sown leys, particularly in the east of England, with consequent weed competition and ingress.

“Some seed was sown last autumn into very dry soil and by November the seedbed was dry as dust,” he says. “This has been a particular problem on lighter soils which were difficult to consolidate. In these cases, the weeds have grabbed their opportunity to take over.”

Weed biology specialists at Corteva Agriscience have also noted an increase in early herbicide applications in new sown leys.

“Some grass fields have become dominated by chickweed, while others have a plethora of weeds including seedling docks, seedling thistles and annuals like knotweed, mayweed and red shank,” says Corteva Agriscience’s Dr Nicola Perry.

“If chickweed is the main problem, or where significant dock populations were present at the time of reseeding, treating with Envy (florasulam + fluroxypyr) is a good idea as this can be sprayed at a good dose rate of 1.5-litres/ha. It also works well at the start of the season when there are dramatic variations in day and night time temperatures.

“Where there is a wide range of weeds growing, including thistles, treating with Leystar (clopyralid + florasulam + fluroxypyr) would be better as this has a broader spectrum of activity. Both Envy and Leystar are very safe to grass but will kill clover. If having legumes in the mixture is important, spray out the weeds first and stitch clover back in after three months,” she advises.