Satisfying the appetite of a 3.5MW anaerobic digester requires a serious amount of forage and an equally serious forager to deal with it.

So when faced with the prospect of having to gather in a couple of thousand acres worth of wholecrop rye and maize, Mark Bates decided to give Fendt’s flagship Katana 85 a try.

Famers Weekly paid him a visit just after it had chewed through its first 5,000t.

See also: Bigger Fendt forager breaks cover

Why the Katana 85?

We had a Claas Jaguar 950 last year, which we used to chop the first 4,500t of maize. It went well, but we just couldn’t get it to give a consistent enough chop length.

We’d heard good things about the Katana and liked the set-up with three pairs of sprung feed rollers.

Our local dealer Chandlers also promised there would be a backup Katana 65 if anything went wrong.

As we have so much to get through we can’t afford any downtime, so that gave us the confidence to give it a try.

Is the chop length consistent?

In the rye it has been fantastic and there is very little variation in chop length.

We need to get an 8-9mm chop for maximum efficiency and it has been giving pretty reliable results so far.

It also seems to feed very evenly and there are rarely any lumps coming out of the spout.

What is it like to drive?

From the seat it is a seriously quiet and smooth machine to operate. The pulse-operated hydrostatic joystick is lovely to use and the interior finish is top-notch.

I also like the fact you can sharpen the blades and put the shearbar in and out without getting off the seat. You can’t do that with the 65, which was one of the clinchers for us going to the bigger model.

My only real complaint is that the work lights are rubbish.

How’s the power?

Power is pretty impressive, too. In heavy rye crops we have been able to go about 9kph with our 6.2m wholecrop header, but in the lighter stuff we have pushed that up to about 14kph.

We used eco mode to start with and it went pretty well, but when you press the power button it’s like you have had a second engine bolted on the back.

So nearly all the rye got cut with that switched on. We might use eco mode more a bit more in the maize.

Is it good on fuel?

It is hard to compare it to the Claas as we haven’t used them in the same crop yet. But as a guide, if we started with the 1,200-litre tank brimmed at 7am and drove it in power mode all day it would need a top-up at about 10pm.

Due to the power it doesn’t have to have an AdBlue tank, which is one less thing to have to do each day.

Which headers did you go for?

For wholecrop we bought a 6.2m Zurn Profi Cut. It has done a good job so far and seems to be a decent match for the forager.

We have been averaging between 270t/hour and 300t/hour, which we are happy with.

The only teething problem we had was getting the driveshafts to line up, but Chandlers sorted it pretty quickly.

We opted for a 12-row Kemper maize header and that’s due to arrive in the next week or so.

I’m hoping it’ll get on with it better than the Orbis header we had on the Claas – that seemed to block all the time.

How easy is it to get the corn cracker out?

Very. For short periods you can swing it out of work by pressing a button in the cab. To take it out completely is five minutes’ work – you just undo four bolts and lift it out.

What did you pick from the options list?

The only extra we specified was a 1m spout extension as it gives a bit more room for the trailer driver when we are cutting maize.

We also got a spout camera in the deal, which is pretty useful, particularly when the trailer is a metre further away.

How long is the warranty?

We got a three-year unlimited warranty and service agreement in the deal. That way we know our costs and don’t have to fork out for any nasty surprises.

We’ll look to trade the forager in before that deal runs out.

How much did it cost?

For the forager, wholecrop header, maize header, warranty and service package, we paid £550,000.

Any dislikes?

Other than the work lights there’s not much to dislike. We have only put 95 hours on the clock, though, so other things might pop up when we have spent a bit more time with it.

One thing that’s a bit behind some of the competition is that you can’t swing the front of the feeder housing out. But it’s not really a problem for us.

Holdingham Biogas

Mark Bates (pictured) and his business partner Robert Beck are in the middle of a project to establish a 3.5-megawatt anaerobic digester near Holdingham, Lincolnshire.

The plant is due to fire up in September 2015 and will be fed using a combination of energy beet, maize and wholecrop rye, all grown within a 10-mile radius of the site.

Total cropping area is about 1,400ha, which is a combination of rented ground farmed in hand and contracts with neighbouring farmers.

Feedstocks are building up and so far Mr Bates has got 4,500t of maize and 5,000t of rye clamped. The first crop of energy beet is also in the ground.

The farming side of the business is growing steadily and most frontline duties are carried out using a Fendt 939. This has duals fitted all round for drilling duties and is teamed up with a buck rake and extra balasting for clamp work.

A neighbouring contractor also drafts in a JCB 435 to help deal with the large quantities of crop and Mr Bates has got a Volvo wheel loader on order, too.

Most of the rye crops have been established using a Horsch Terrano drill and the maize has been put in with an 9m Amazone Edx.

Next on the wish list is a second tractor, which will either be a Fendt 724, or something a bit simpler that anyone can hope on and drive. He’s also keen to try the new 1000-series when it eventually goes on sale.

Building phase

At the time of writing the AD site was in the first construction phase with bases for the twin 32m-diameter tanks going in as well as access roads and connection to the grid.

The gas produced by these tanks will initially drive a brace of CHP (combined heat and power units). Electricity will flow straight back into the grid, but the plans to deal with the heat generated are still up in the air.

Originally it was destined to heat a series of poultry houses, but planners turned this down.

Now he hopes to use it for growing either tomatoes or soft fruit. And there’s another potential plan in the pipeline to dry soggy straw bales before they go into the nearby Eco2 power station.

A gas main passes close to the site, so eventually the plant might be modified to pump gas directly into that.