Miscanthus was first identified as a perennial crop for set-side ground on Irish tillage farms almost two decades ago.
Back then it was grown as a bio-energy option which, when mixed with peat, could be sold as a valuable fuel source to Irish industry and home-owners.
However, this business plan started to run out of steam as successive governments legislated to minimise peat harvesting and burning across the country.
In response to these trends, the area of miscanthus started to drop-off significantly.
Miscanthus in Meath
However, this was not the case on the Co. Meath farm of the O’Keeffe family, who identified that the crop can be put to use as a ‘super’ bedding material for livestock of all kinds.
As it turns out, miscanthus has absorbency powers that are far superior to either straw or peat. And when finely chopped, it can be used as a bedding material without comparison in stables, poultry units, traditionally bedded livestock courts, and dairy cubicle systems.
The production of miscanthus perfectly complements a tillage operation; not from the point of view of adding to a specific rotation, but rather from the perspective that the crop requires good land in order to meet its full growth potential.
In addition, the crop requires ‘active drying’ under Irish growing conditions. This entails the use of handling and storage facilities that are most commonly found on tillage farms.
What is miscanthus?
It is a tall perennial woody grass of east Asian origin, which has a high biomass yield potential. The crop has been evaluated at Teagasc Oak Park since 1993.
This work has confirmed that miscanthus grows best in areas that have relatively high temperatures and are predisposed to high solar radiation. The conditions required for growth are not unlike those for maize.
However, miscanthus has a lower threshold temperature in comparison to maize. The results from the Oak Park trials confirm that annual yields in the range 10-15t/ha of dry matter can be achieved under Irish conditions.
James O’Keeffe farms at Creevagh, near Crossakiel in Co. Meath. He currently grows 56ac of miscanthus. The family had previously established an initial 24ac of the crop as a set-aside commitment back in 2006.
Organic cereals and beans, grown to the highest possible standards, make up the rest of James’ farming operation.
Red clover is also grown as an integral part of the crop rotation followed across his 180ac of crops.
“The original miscanthus area was planted out with the support of a 50% set-aside grant back in 2006,” he explained to Agriland. “And it has been fully retained since then.
“The plan is to further expand the area of miscanthus grown on the farm. But this will be undertaken at our own expense; grant aid is no longer available.”
The crop
According to James, miscanthus is a hard crop to establish. It requires good ground and a soil pH of 6.8, in order to maximise production levels.
The crop is planted out in the form of sterilised rhizomes, which are sourced from the UK. The sterilisation process ensures that the subsequent crop will not enter its flowering and seed production stages
“The rhizomes are physically placed in the ground by operators sitting on a machine that resembles an old potato planter,” James explained.
“It’s a pretty slow and man-power-intensive operation.”
Rhizomes are planted out a density of about 16,000/ha. An initial establishment rate of around 90% can be expected.
Sites that are fully exposed to sunlight throughout the year are required to maximise crop performance.
“Newly established crops are left untouched for two years. After that, they can be harvested on an annual basis,” James continued.
“Individual plants will reach 10ft in height. Miscanthus is a perennial crop. Within our own farming operation we are still regularly harvesting the sites that were established almost 20 years ago.”
The harvesting of miscanthus gets underway around the middle of March. The leaves produced by the previous year’s growth would have fallen off the plant stems towards the end of the previous November.
“The stems are cut down to almost ground level and allowed to air dry for a month,” James said.
“The plan is to get the crop as close to a 15% moisture content in the field as possible. Depending on the weather and ground conditions, the miscanthus is harvested around the middle of April.
“It’s important to get the crop off the ground before the rhizomes start to put up new shoots.
“The period directly after harvesting is critically important. In terms of a fertiliser requirement, a generous application of cow or pig slurry is all that’s required,” he added.
Fertiliser and weed control
There are cattle sheds on the O’Keefe farm, which are rented out to local livestock farmers. The slurry from their cattle provides the fertiliser nutrients required by the miscanthus.
“If required, additional slurry is available from local pig producers,” James continued.
Weed control in newly established miscanthus crops is important. Grass weeds can out-compete the newly planted rhizomes and the appropriate management steps must be taken.
In more mature crops, weed control becomes less of a challenge. As soon as a crop gets up and running, the amount of light getting through to ground levels falls off dramatically.
In addition, the leaves that fall from the stems during the autumn period form a thick mat at ground level. This prevents the germination of new weeds during the subsequent spring period.
“Some perennial weeds, such as scotch, can be a problem,” James further explained.
“However, they can be treated effectively with a suitable herbicide prior to the emergence of new shoots directly after harvest.
“Miscanthus is not prone to any diseases that we know about under Irish conditions. So there is a zero requirement for fungicides and chemicals of this nature. In many ways, this complements the organic grain business.”
Directly prior to the harvest, the miscanthus is rowed up, as would be the case with any crop of grass.
The crop is then lifted by a local contractor with a precision chop harvester, set for a chop length in the range 1-2.5cm.
“This is a pretty heavy duty operation,” James explained. “The miscanthus is very woody in nature and it takes machines in the 800 to 900hp capacity to get through it,” James explained.
The chopped miscanthus is then taken to the main yard in trailers, where it is placed in sheds with floor drying facilities.
“This year, the crops coming off the fields have a moisture content of around 20%,” James commented.
“We need to get that figure down to around 15%. So active drying will be required. In terms of output, we are looking at an average yield of around 5t/ha in dry matter terms.”
Usage
All of the miscanthus produced by James is sold for bedding.
“We are working with equine businesses and livestock farmers from as far way as Co. Galway,” he confirmed.
“The bedding material is sold on a cubic metre basis at a guaranteed moisture content of 15%.
“Driving all of this is the fact that the chopped miscanthus has very high levels of absorbency. This means, it can soak up large volumes of effluent while keeping stock dry.
“Another advantage is the fact that miscanthus is an inherently sterile material. This is of critical importance when used as a bedding material for broilers and laying hens.
“Specifically, where poultry clients are concerned, we will also test the material for pathogens prior to delivery.”
Looking to the future, James is also seeking to develop greater numbers of customer outlets for his miscanthus within the dairy sector.
“We are involved in on-farm trials at the present time,” he explained.
“The miscanthus bedding can be used directly by the likes of Bobman cubicle cleaners without the need for any alteration to the specification on the machine.
“And on that basis, the material should be very attractive to dairy farmers. We will coordinate delivery of the miscanthus to customers on a countrywide basis.”
“From a production point of view, miscanthus is a perfect complement for any traditional or organic tillage operation.
“In our own case, we are trying to deliver added value across all the crops that we grow,” James added.
“It’s all about developing a closer relationship with the end consumer. This approach is the only way that I can see of securing the premium prices required to deliver sustainability for all farming businesses.”