According to Wynnstay dairy specialist Mark Price (pictured), the improved nutritional value of maize silage grown under film, outweighs the increased growing costs.
“The total additional fixed and variable costs of growing maize under film amount to approximately £300/ha compared to conventionally grown maize. However, the increased nutritional value, typically 6% more DM and 3% more starch, equates to around £520/ha more than conventionally grown maize,” says Mr Price.
“Once growing costs have been taken into consideration, this delivers a net gain of around £200/ha.”
Dr Simon Pope, Wynnstay crop protection manager, says there are also agronomic benefits of growing maize in this way.
“When maize is sown under biodegradable and photodegradable film it creates a microclimate, warming the soil and increasing the soil temperature to above 10°C, which is the base temperature required for germination and growth,” he explains.
“The film reduces moisture loss and by warming the soil the availability of nutrients is improved. The result is quick establishment and greater root development and the more favourable growing conditions ultimately go on to provide higher yields of DM and starch in early maturing crops.”
Dr Pope says an early harvest also provides an opportunity to get a catch crop in the ground shortly afterwards.
“This not only helps improve soil condition, but also provides valuable additional feed. It’s been particularly crucial this season off the back of a difficult year for forage production.”
For welsh dairy farmer Rowland George, growing maize under film has played a key role in maintaining his high yielding herd.
“We’ve grown maize this way on and off since 1994 and have always seen the benefits of the investment,” he says.
In 2018, Mr George grew 45ha of maize under film to form part of the total mixed ration (TMR) for his 1,600-head dairy herd.
“Not only are we able to get the crop off sooner, we’ve also seen increased starch content at 35%, and higher DM yields per acre, providing a safety net for bad maize growing years where maize under film still reaches maturity,” says Mr George.
“Thanks to this improved nutritional value, we’ve seen a significant increase in both milk yields and herd fertility compared to if we weren’t feeding maize forage, we’d have to buy-in alternative feed to supply the required energy. This would be much less cost-effective than growing maize under film, and we certainly see the value when we review our feed costs,” concludes Mr George.