"We do all kinds of tillage operations from ploughing right through to cutting, baling and even drawing in the straw if needed. We also make baled silage, pit silage, spread dung, slurry and fertiliser," Nicholas says. "But we don't get involved with maize, beet or hedgecutting. Hedgecutting wouldn't suit us as most of it is done at the backend of the year when we are very busy and it would tie up a man and a tractor."
The Brennans' tillage operation is sizeable, ploughing and sowing around 3,500ac of spring and winter cereals, including wheat, barley, oats, oilseed rape and some beans.
Nicholas says that it's been a good few years since they have sown beans.
"They seem to come and go," says Nicholas. "Oilseed rape comes and goes quite a bit as well, depending on the price. Last year was a very good year for it but lads need to be lucky with it. Farmers around here were fierce unlucky with spring oilseed rape last year. The week before it was due to be harvested it got windy and most were lucky if they got a tonne to the acre."
Nicholas feels that beans and oilseed rape are a gamble.
"You can make a lot of money one year but maybe next year lose it all," he says.
About the steadier wheat, oats and barley crops, Nicholas says: "Nine times out of 10, you will come out on top."
While located in Co Carlow, the Brennans are in the heart of the south-east close to the Laois and Wexford borders and even closer to the Kilkenny border.
"Land is heavier further west in Kilkenny and we sow a lot of winter wheat over there," he says. "In Carlow, we sow more spring crops but in Tullow it's back to winter-sown crops again."
The lads harvest around 2,800ac and run three combine harvesters to keep big and small customers alike satisfied. All are Claas harvesters, two Lexions and a Tucano.
Up to 2007, the lads ran two Lexion combines but, as Nicholas says, they ended up hiring an extra combine for 90pc of each harvest during the bad weather harvests of 2008 and 2009.
"So for the 2010 harvest, we traded back in the Lexion 580 and bought a Lexion 570 and a Tucano 440," he says.
"You could probably cut 2,000ac with one Lexion 580, but our biggest problem is that most of our cutting is winter wheat and spring barley and it all ripens together. When the customers want their corn cut, they want it cut and you can't be in two fields at the same time with one combine.
"It's the weather that's probably the biggest challenge for us because when it's bad there is downtime with men and machines, then we have to hire extra machines to cope," says Nicholas. "If it is a good year then we have spare capacity to take on extra work. But, at the end of the day, providing a service is number one for us. You can't let customers down at the last hurdle. It's all about customer service and providing that service when the customer needs it."
To provide this level of service, the Brennans, like everyone else, have to get paid.
"We do expect a fair price for work done and fair payment. When we need to get paid, we get paid," says Nicholas.
The Brennans have used the same fuel firm since 1978, Dobbs Oil, in Tullow, Co Carlow. While not necessarily the cheapest, Dobbs treat the Brennans fairly with supply and the brothers reciprocate by keeping on top of the bill.
Rising fuel prices, though, are a problem and have to be reflected in the price of work done.
"We have to get enough money for the work done without over-charging the customer," Nicholas says. "Last year, we had to put up a lot of the prices because of the cost of the diesel.
"There are cheaper contractors out there but customers have gone away from screwing the contractor down to the last.
"They are now happier to pay a little more and have the work done when they want it done."
The Brennans are acutely aware of the latest round of exhaust emission controls and the problems that low-sulphur diesel brings. Their 2008 Fendt 820 is in the process of being changed but instead of going for another 800 series, they have opted for the smaller and cheaper 700 series, buying a new Fendt 724. Engine power is increased but it is a smaller tractor.
Also new for this season is a John Deere 6170R but Nicholas claims that each tractor has cost them €10,000 more than the deals they did in 2008.
"Manufacturers say it's down to emission control but ultimately it's the last man, us, that pays the piper," says Nicholas.
Diesel prices are the other big issue.
"Diesel is already expensive but this new low-sulphur diesel is even more expensive, especially with some of the tractor manufacturers recommending that you put an additive in the diesel, a biocide, which costs another 3c/l," he adds.
The Brennans recently spent €1,200 getting their main fuel tank and two bowsers cleaned out to ensure they were up to spec to avoid any downtime in breakdowns.
The Brennans kit is all fresh and is purposely kept that way.
"We tend to change our machines regularly, as soon as they are paid for," says Nicholas.
"This is to do away with the extra cost repairs and breakdowns. Fewer breakdowns mean less downtime away from work."
Again, this comes back to the focus on service.
"If you don't keep up (with good kit), you'll fall behind very, quickly with breakdowns and downtime. Before you know it, your service has slipped."
Nicholas also believes that changing machines regularly is important from a finance point of view.
"You are making use of the equity built up in the machine by trading it in while it is still fresh, which is an important thing from the finance point of view," adds Nicholas. "No-one is giving 100pc finance anymore. The trade-in is your deposit, so the bigger the value of your trade-in, the bigger the deposit."
With the times that are in it, the cost of finance has gone up but there are now more options according to Nicholas.
"Finance has become expensive but own-brand finance is a big help with Claas, AGCO and John Deere all offering packages," he says. "The problem with that though is that these are subsidised finance packages from the manufacturer so the cost of the tractor goes up."