The additional costs associated with growing maize under film can be more than covered by the value of the increased DM yield and the increase in starch yield.
Drilling under film is a one-pass operation; the pre-emergence herbicides are applied, the seed is drilled, the film is laid and last of all the soil between the rows of the film is sprayed.
Maize plants develop more rapidly as they have large leaves to capture more sunlight. This results in higher DM yields, higher starch yields and (depending on variety) much earlier harvest.
The film acts like a miniature greenhouse, warming the soil and creating ideal conditions for plant growth.
Growing costs under film are higher than for conventional crops (typically an additional £250/hectare, but this is greatly outweighed by the higher crop value generated by elevated DM and starch yields.
Maize needs a soil temperature of 10oC to germinate and become established. The soil temperature rises quickly under the film, so maize can be drilled much earlier in the year, greatly increasing the length of the growing season.
Earlier harvest date and more consistently reliable crops, when grown under the film, allows maize to be grown in areas where conventionally grown crops may be borderline.