Sow pastures early; don’t wait for rain

Sow pastures early; don’t wait for rain

February 16: New research confirms it’s better to sow treated pasture seed early in dry autumns instead of waiting for rain before planting.

Benefits include faster pasture establishment, higher DM yield and potentially better pasture persistence, plus it’s easier to get a contractor.

That’s good news for farmers who want to get a head start on feed recovery after the current drought, according to agronomist Will Henson, Agriseeds.

“Last year many farmers did not sow while it was dry. When the rain did come in April, it kept raining on and off for the next three weeks; contractors were working 24 hours a day and still couldn’t keep up. The end result was that a lot of sowing that should have been done, wasn’t. And paddocks sowed late were slow to establish, yielded less and were more difficult to manage through winter and early spring.”
Will says the main questions with early sowing have always been around how well seed and endophyte survive in hot, dry soil, as well as the possibility of poor establishment.

“There hasn’t been a lot of research done on this, so we decided to test it last year.

“Now we’ve been able to show that Trojan ryegrass seed with NEA2 endophyte can keep well in the soil for six weeks without significant rain, and establishment is much better than if planting is delayed until after rain.”

In a replicated trial near Cambridge last autumn, Trojan perennial ryegrass with NEA2 endophyte was sown on three dates: 20 February, 20 March and 27 April. All seed was treated to protect it from insects and disease.

The first sowing was in very dry conditions, and seed sat in the soil with no sign of germination until 45 mm of rainfall on 4 April, 43 days later.

“We deliberately chose dark peat soil for this trial, because it is known to reach very high soil temperatures in late summer and early autumn,” Will Henson says.

At the seed sowing depth, the soil temperature at 10 am on 20 February was 49.1°C. On 20 March it was 41.7°C and on 27 April, it was 27.0°C.

Two key results stood out. First, seed sowed early established quicker and grew more. The February and March sowings grew 2 t DM/ha more than the Apr sowing (5.8 t versus 3.8 t), measured over five grazings from May to October.

“At the Forage Value Index figure of 38c/kg DM, that extra 2 t DM/ha equates to $760/ha of valuable winter feed,” Will points out.

Second, endophyte levels were not affected by early sowing; these were the same for all sowing dates.

“Early sowing has several benefits: contractors aren’t so busy; seed is set to grow when rain comes; new pasture is ready for its first grazing sooner; winter growth is better, and this sets up better persistence.”

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