The issue is important, not least because of the impact of chemical fertilisers on climate change. I read in last weeks’ Farmers Weekly about a farmer who had recently undertaken a carbon audit which concluded that 80% of his emission footprint came from the use of nitrogen fertiliser. Whether or not that is accurate, what is beyond question is that agriculture’s umbilical dependence on nitrogen fertiliser is now being questioned as never before.

After I finished milking and was moving the electric fence for our cows’ daily parcel of mob grazed herbal ley, I was quietly marvelling at the extraordinarily productive capacity of their 12 and a 1/2 acre field. This field has not only produced three excellent cuts of silage but over the last week has fed 80 cows who have produced around 7,000 litres of milk which will convert into around 3/4 of a ton of cheese! All this from the field which has now been around our seven year rotation four times and is more productive than ever.

Marvelling at this productivity, which has been achieved with few external inputs, just crop rotation, herbal leys and recycling of animal manures, I realised that I am in an unusual and  interesting position, having been farming without any nitrogen mineral fertiliser for nearly 50 years and observing the impact of my farming practices on yield outcomes. Not many farmers in the developed world can claim to be part of this cohort, since the overwhelming majority of food producers have been nitrogen fertiliser dependent since the post-war period.

…click on the above link to read the rest of the article…