Maize under plastic

Published 28 February 14

Maize under plastic – in brief

March is the time for thinking about seed bed preparation for maize under plastic.

Maize under plastic is planted so early in the year because:

The warming effect of the plastic “cloche” raises the air and soil temperature below the plastic to a level which allows maize to be drilled two to three weeks earlier than would otherwise be the case 

This earlier start to crop growth combined with a faster rate of heat unit accumulation under the plastic, that is, until it degrades, means an earlier harvest in the autumn

In the marginal wetter west of the country this can make the difference between bare maize stubbles being left all winter or ideal establishment conditions for a following crop.

Effect on yields

Research from Northern and Southern Ireland, over many years, shows higher yields from maize under plastic, and greater maturity, than uncovered crops in similar locations. 

But these benefits come at a considerable cost, and are very much average benefits, with plastic having little effect on good growing years, and considerable impact in poor years. 

Working on Irish research average yield improvements, and the current cost of using plastic, the cost per tonne of maize DM has been calculated to be similar to uncovered marginal crops.  

The combination of the above positives, plus the increased working window for machines, is convincing more growers to have a go at maize under plastic. 

For more information go to The Maize Growers Association.