24 July 1998

HOWLEAFUNIT SPREAD LOAD

AN early start to wheat drilling and repeated seed rate cuts are easing autumn management with few downsides at Stanaway Farm, a 220ha (544-acre) LEAF demonstration unit at Otley, Suffolk.

Manager Matthew Ward introduced earlier sowing when he took over the heavy land farm three years ago, mainly to ease the post-harvest labour peak.

"It spreads the workload. In the open autumns we have since had we have seen no yield benefit. But if we got catchy weather and ended up muddling crops in in October, all the research shows yields would start to fall off quite dramatically. We cannot risk having nothing in the ground in September."

Just 25mm (1in) of rain on the sticky soils means a weeks wait to return to the land, he notes. But until earlier sowing is proven over several seasons he is reluctant to commit himself to too large an area or too great a rate cut.

The farm grows 115ha (284 acres) of winter wheat, split this season between five varieties to spread market and disease risks.

Current strategy is to sow about 20% of the area weekly from very early September. "Last year we started with Consort on Sept 3. We then waited because we dont want to put all our eggs in one basket.

All seeding, using a 3m KRM power harrow/drill combination, is based on thousand grain weights. Up to 60% is with farm-saved seed which Mr Ward maintains is as good as or superior to certified material when properly tested and cleaned.

"Initially we used 220 seeds/sq m because establishment can be quite difficult on this soil. Slugs are a big problem and pellets are a bit hit and miss. Sowing early helps crops grow away from the slugs," he says. Minimal cultivation predominates to conserve moisture and the plough is shunned except for second wheats.

"But we have come down 20 seeds each year, so this season we were on 180 which worked out at 102kg/ha. I am comfortable with that. Trials suggest we could get a yield benefit from less, but that level gives us a manageable crop.

Rates are increased by about 25 seeds/sq m for each successive weekly sowing. "So we are up to about 300/sq m by the end of September." Another 10% is added wherever ploughing rather than discing is the primary cultivation, mainly for second wheats. Shy tillering varieties, like Buster, may also merit more, he adds.

Variety traits determine drilling order. "Some varieties lend themselves better to early sowing." Consort is more suitable than Equinox because it develops more slowly in the spring. Late frosts killed some main shoots in the latter last season, he notes.

Last autumn the sequence was Consort, Abbot, Reaper, Equinox and Charger.

Drilling extra early brings potential snags, not least weeds, says Mr Ward. "We have two fields with bad blackgrass which I certainly wouldnt think of drilling in September."

Early sowings usually also need an extra autumn aphicide spray, but until this year they have required no more expense on fungicides or growth regulators than later drillings. However after this seasons open winter Consort unusually warranted an eyespot spray and extra Terpal (2-chloroethylphosphonic acid + mepiquat chloride).

Suggestions that early sown crops might make better use of soil mineral nitrogen tempted him to omit the first 40kg/ha (32units/acre) nitrogen top dressing two years ago. "But it then turned very dry and we had massive tiller loss and the crop never recovered. Now we still apply early N but reduce the amount by 10-20kg/ha in each of the second and third splits and that seems to be working much better."

Direct yield comparisons between drilling dates are hard to make. Indeed one later sown field of Consort last year gave 9.1t/ha (3.7t/acre) against the 8.9t/ha (3.6t/acre) from an earlier drilling of the same variety. But Mr Ward remains convinced of the practical benefits starting early with relatively low seed rates brings. &#42

EARLYDRILLINGPOLICY

&#8226 Start wheat early Sept.

&#8226 Seed rate adjustments.

&#8226 Spreads workload.

&#8226 Minimal yield effect.

&#8226 Marginal extra expense.