In my last column I was extolling the virtues of the ammonia fixing process which allowed the manufacture of nitrogen fertilisers – and argued that it was probably one of mankind’s most important inventions ever.

And, as there would probably be many, many millions starving today without it, I would stick by that assertion.

However, I’d admit that, as in many areas of life, you can sometimes have too much of a good thing – and just in the past week the Scottish Government announced that it was funding a project to look at ways of ensuring that fertilisers are used efficiently, with an apparent view to reducing emissions of greenhouse gases and the leaching of nitrates into the wider environment which can occur when the stuff is over-used.

Now there was a bit of a fuss when this was first revealed – and anyone reading between the lines would have been forgiven for viewing the announcement as a precursor to the introduction of targets and restrictions a short trip down the line.

NFU Scotland reacted by pointing out that research had shown that the use of synthetic fertilisers accounts for only a small share of total agricultural greenhouse gas (GHG) emissions – under 7%.

Even if the widely quoted 'fact' that agriculture is responsible for 30% of total GHG emissions is correct, that means that less than 2% of total GHG emissions come from synthetic fertilisers.

That said, the nitrous oxide which is perhaps more likely to be released from Scotland's cold damp soils than elsewhere is a pretty powerful GHG – in the order of 300 times more potent than carbon dioxide. And, of course, while these emissions are important, producing fertilisers also uses up vast quantities of fossil fuels, a process which accounts for another huge swadge of GHGs.

The union’s crops chairman said that while he was glad that the Scottish Government had recognised that nitrogen is a key component in crop nutrition and in raising crop yields, any findings or recommendations coming out of the study should be based on sound science – including economics.

A bit of digging put me in touch with the scientist who is leading what will be the initial phase of the work. She certainly made it sound a bit less insidious than the scenario which the more suspicious amongst us might have been imagining.

In fact, the mainstay of this phase of the research project is going to revolve around an evaluation of the tools, formulas and computer programmes which we use to draw up our nutrient management budgets.

For long gone are the days when we just chucked fertiliser about willy-nilly – both harsh economics and environmental conscience (and legislation in the form of Nitrate Vulnerable Zone directive!) now sees almost everyone draw up a pretty detailed nutrient plan and budget their fertiliser applications accordingly.

Now there’s quite a wide range of management tools and computer programmes out there from a number of sources – one of the better known being the PLANET software widely touted a few years ago for NVZ areas – but it would appear that there hasn’t really been much work done on deciding which of them are best suited to the conditions we have here in Scotland.

As different tools give different weightings to organic manure dressings and the residual nitrogen left form previous crops, they can give different recommendations for nitrogen applications – and they can’t all be right.

Of course, there’s also the issue of just how 'farmer friendly' these programmes are and this will have a considerable influence on just how well these they’re actually utilised by farmers on the ground. If they’re not properly understood, incorrectly used – or just plain awkward to get an answer from – then they’re not going to be giving the sort of results which they should be.

So, filling any gaps in the existing knowledge about these nutrient budget tools and enhancing any shortfalls is likely to provide the much sought after 'win-win' situation where wasted nitrogen can be avoided and costs, emissions and leaching can all be reduced.

But if this does lead to any notion of targets and restrictions down the line a bit, there will be plenty of room for argument – as the means of reducing any negative impacts of fertiliser fall under a fairly limited number of headings:

* Use less nitrogen fertiliser;

* Use split dressings; use legumes or grass in the rotation;

* Use min till for cropping;

* Avoid waterlogging;

* Use of nitrification inhibitors and so-called controlled release products, such as polymer-coated urea.

Other 'back to basic' issues such as keeping an eye on pH levels and making use of any available organic manures also have a key role to play.

So, on this front, it was good news to hear that there could soon be a solution to the current challenge facing arable growers supplying crops to anaerobic digestor (AD) plants who find themselves banned from using the resulting returned digestate on land which grows barley crops destined for malting and distilling.

Hats off to SQC for taking on the task of drawing together the new 'Green feedstock digestate assurance scheme' which is currently in the final throes of a consultation – and which is likely to be launched later in the spring.

Alistair Ewan, the executive director with SQC, said he hoped that the 'digestate passports' – which will guarantee that the useful fertiliser and soil conditioner left over after the AD process had been completed has come from farm feedstocks, rather than commercial waste – would convince the maltsters and distillers to accept crops grown using the product.

With estimates suggesting that upwards of 50,000 acres of arable land will be growing crops destined for AD plants by 2022, there is a real need to ensure that the resulting digestate can be used effectively and efficiently without threatening the ability of grain growers to meet the requirements of high quality markets such as malting.

However, to date, there has been a reluctance amongst distillers and maltsters to accept grain from crops grown using this useful source of plant nutrients. For while all digestate returned to farms must meet the BSI PAS 110 industry standard, there is currently no guarantee that it comes from farm sources, as other bio-wastes such as supermarket sandwiches can be used in some AD plants.

However, it looks like the 'simple but robust' scheme being proposed could ensure the provenance of the digestate being returned to farms – and hopefully make it acceptable to the whisky industry while at the same time allowing the nutrients and conditioning elements in the product to be returned to the land and effectively recycled in line with good farming and environmental practices.

The Scotch Whisky Association has given its support in principle to the idea, as has SEPA and AD operators have also been relatively positive towards the proposals – hopefully the hard work will pay off.

So, it just goes to show you that with a bit of hard work and a little bit of common sense, we might be able to look forward to a future which is both sustainable and profitable. Just don’t hold your breath.