Many years ago, when we were at Rawburn, we had a client from the South of England who bought 100 Mule ewe lambs privately every year.

On one occasion, I showed him a 110, hoping that he would take them all. No, he just wanted 100 and it took him hours to make up his mind which ones he didn’t want.

When I told an elderly shepherd who was helping me to dress the sale tups, he replied that my grandfather – who had employed him in his youth – advised him in similar circumstances, that he should always put some in for the buyer to take out.

I have just signed up to do a carbon audit at Roxburgh Mains. Although I absolutely agree that we all must do our bit to mitigate climate change, I suspect that the carbon audit will be a tedious affair and, so far, have always found something more important to do.

I have read many articles on the subject and so am well briefed. Apparently, we will only gain credit from those paying our single farm payment on improvements made after the carbon audit, so we mustn’t start work too soon.

We must start with our farms looking as environmentally hostile as we can, which will leave plenty things for them to take out.

Questions remain in just what we measure and how we measure it. The list looks ominous and I don’t look forward to providing the data required.

I hope that, if I do it conscientiously, the farm and our bank balance will improve as well as satisfying our paymasters. Some of the information is easy to find. We know how much diesel and electricity we used. How we split it up between the crop, cattle and sheep is not so easy.

We know how many cattle and sheep we have. Going through the movement records to find when they were on Roxburgh Mains and when they were on rented grazing will take time.

It shouldn’t be difficult to get information about fertiliser use and whether it was spread on crops or grass. We know how much feed we bought and how much was grown on farm.

Allocating time spent by ourselves and our farm staff, particularly when we sometimes have two vehicles on the road delivering cattle from Orkney to Devon for months on end, nears impossibility. We must do our best and hope that it benefits the environment by highlighting key areas we can focus on to reduce our carbon footprint without affecting profitability.

I read that, on an arable farm, 60% of its carbon footprint comes from nitrogen, 20% from power, 10% from seed and 10% from phosphate, potash and other nutrients, so nitrogen is obviously a starting point.

It appears that the experience of others doing a carbon audit exercise indicates that we can use a little less without losing too much yield in our spring grain crops.

Grass nitrogen will be more difficult to cut back as the stock carried relates directly to how much we spread. We don’t buy much phosphate as we have a high stocking rate and plenty dung. The only potash we spread is on silage ground, so cuts there, too, are limited.

The carbon footprint from seed seems very high. We don’t keep any of our own, so that will make no difference to us.

Reducing power requirements and carbon emissions on arable farms means, for many, replacing the plough with direct drilling or min till.

When I took Roxburgh Mains in 1993, my experience at that time had been as a hill and upland farmer. We did grow crop and renewed the grass on the hill farms, but our techniques were basic compared with those lower down.

I relied heavily on advice from John Forrest, my predecessor in the farm. Due to the stony nature of the soil, he sowed the autumn crop of wheat, barley and oilseed rape after heavy discs. It was quick, kept the stones down and saved diesel, although that wasn’t so much an issue at the time.

Yields weren’t compromised. John advised that it didn’t work with the spring crops, so the plough was used and the stones hand gathered, which was a time consuming task which no-one enjoyed.

Calculating the carbon footprint of our livestock will be more difficult. Farming magazines haven’t provided much information about how other livestock farmers are reducing their carbon footprint, so we will have to find out the key areas and the location of our hot spots for ourselves.

Much has been written about the benefit of cover crops and, even better, grazing them. We have been doing that for years, so won’t count as an improvement by the government.

In tandem with the reduction in our carbon footprint, I hope that our programme to reduce the methane footprint of our cattle will gain some kudos with government.

When we installed the equipment to measure feed efficiency in our young bulls, methane reduction – although secondary – was nevertheless important to us. The cost of the operation dictates that we can only afford to test the bulls, so at present we are identifying the best converters and associated genetic trends.

When we find the bulls that are most feed efficient, excel in other traits which we already measure and are also eye appealing, we will use them heavily.

Feed efficiency is highly heritable, with no downside, so improvement will accelerate after that with a reduction in feed costs and methane production in the whole herd.

Genetic improvement, coupled with new feed additives which reduce methane emission, provide a strong counter to those who contend that the only way to make beef cattle more environmentally friendly is to reduce the nations cow herd.

Indeed, it demonstrates that grass grown in Britain and the animals which graze it not only maintain the environment but also enhance it.