Farming and Fertilizer

Fr Donal Dorr

As we all know, nearly 80% of the air we breathe is nitrogen. Most of us also know that plants, in order to grow, need nitrogen. But the nitrogen in the air has to be chemically transformed before plants can use it. For thousands of years farmers had to rely on natural processes to bring about this transformation. Farmers used “natural” fertilizers such as cow-dung or sea-weed; and they mixed and rotated their crops to preserve the fertility of the soil. The process of turning nitrogen into usable fertilizer took place only quite slowly, so there were limits to the amount of food that could be produced on a particular plot of land.


Just a hundred years ago scientists discovered, almost by accident, a way to turn nitrogen into nitrate fertilizer. Nowadays farmers almost everywhere use manufactured nitrate fertilizer to increase agricultural production. The use of this nitrate fertilizer, combined with the use of pesticides, has brought about a four-fold increase in the productivity of agricultural soil.


All this seemed to be a good thing—and in the short-term it undoubtedly enabled farmers to produce more food and become more wealthy. But we are now beginning to experience the long-term effects which are very serious indeed. The repeated use of nitrate fertilizer allows such a large increase in productivity that the fertility of the soil itself gets exhausted quite quickly. Furthermore, farmers have increasingly adopted a practice of monoculture (planting the same crop year after year), instead of rotating crops as was done in the past. This further hastens the depletion of the soil.


Responsible scientists in Sheffield University and elsewhere have done research on this issue. It is estimated that, after another fifty or sixty crops, up to half of the arable ground of our world will be so depleted that it will no longer be able to produce vegetation. Even in the temperate climate of countries like Ireland and Britain it looks as though another hundred crops will exhaust much of our soil. Furthermore, there is a huge run-off of the fertilizer into streams and rivers; this causes eutrophication, depleting the amount of oxygen in the water and killing off the fish and other water creatures.



It is clear from this example that we all face a serious challenge of a kind  that no previous generation had to confront. We need now to take account of the long- and medium-term effects of the present style of farming. We have to think of what kind of world we are leaving to those who came after us. 

The challenge has to be met at two levels. First of all individual farmers need to recover the best aspects of the wisdom of farmers in the past. They need to learn from the relatively small number of people in almost every country in the world who are showing that it is quite possible to farm in a way which respects the natural ability of the soil to regenerate itself—and that it can even be quite profitable to do so. When some brave pioneers do this, the word can get around, the scepticism of others can be overcome, and the new approach can be adopted more widely.


Secondly, government action is required. Laws and regulations need to be put in place in order to encourage and support those who are willing to do their farming in a way that preserves the fertility of the soil for future generations.