A new Descriptive List for maize was recently launched by the BSPB/NIAB to provide AD (anaerobic digestion) plant operators and growers with independent data to use when selecting varieties to maximise biogas (methane) production. Where growing conditions are Less Favourable, it ranks varieties on earliness (DM%) and at Favourable sites, by Metabolisable Energy (ME) yield. LG variety Atrium tops the Favourable List â with the highest ME content of 11.75MJ/kg DM and highest ME yield of 215,000MJ/ha. For growers wanting an earlier maturing variety, another LG variety, Fieldstar, has an ME content of 11.48MJ/kg DM and ME yield of 207,000MJ/ha.
Limagrainâs Tim Richmond explains: âFarm-based anaerobic digestion is a relatively new, but expanding industry with maize frequently being used as the main feedstock for the digestion process, especially in areas which are âfavourableâ for the crop. Growers of maize for AD need an independent source of information to compare variety performance in order to select the right one. Hence the launch of this new Maize for Anaerobic Digestion List which has been compiled from over 3 years of BSPB/NIAB trial data.â
The new List recognises that the selection criteria for anaerobic digesters are different from those for livestock feeding. To maximise biogas production, it is the total energy (ME) production per hectare that best indicates the potential methane yield of a variety. So this new AD List provides growers with data on energy yield, dry matter content at harvest (earliness), DM yield, plus the important agronomic traits of early vigour, and standing power.
Mr Richmond explains: âDry matter yield is one of the most important attributes when selecting which maize variety to grow as an AD feedstock. Later maturing varieties can generally produce higher yields, and since maize for AD plants can be harvested at a lower DM content (28-32% DM) than for forage use, this makes the later maturing variety Atrium an ideal choice. It combines outstanding energy content together with a very high DM and energy yield.â
Mr Richmond adds: âAs large areas of maize are needed for an AD plant, it is advisable to spread the harvest operation and enable any follow-on cereal crops to be planted in good weather conditions. Growing both Atrium and the early maturing variety Fieldstar, which has an ME yield of 207,000 MJ/ha, enables growers to start harvesting some maize earlier and plant the following crop sooner.â
Mr Richmond concluded: âOver the next few years we expect to see more high-yielding specialist varieties appearing on the Maize for AD List. It will become a crucial decision-making tool for growers and AD plant operators seeking to maximise the performance of maize as a feedstock.â