The ethical debate is always difficult when it comes to food. Our blossoming population will continue to grow, we will have to find a way to feed everyone and fertiliser will be required to do this. While organic farming is better, the International Fertiliser Development Centre says that if the world's 1.5 billion hectares of farm land were farmed organically, there would only be enough food for 2.4 billion people, about one in three of those in the world today.
To support population growth since the 1960s, human use of synthetic nitrogen has increased nine-fold globally, while phosphorus use has tripled and a further increase will be required over the next forty years too.
One has to ask though - how much food to we really need?
The lead authors of the United Nations-backed Global Partnership on Nutrient Management say in their report Our Nutrient World that 80% of the harvested nitrogen in the world ends up feeding livestock rather than people and that Europeans eat 70% more protein than needed, while sub-Saharan African farmers are desperately low in nutrients and thus undernourished.
So the question becomes one of food luxury, rather than food security. The biggest impact that we as individuals can have is to eat less meat. This doesn't mean everyone has to be a vegetarian, it just means we need to reduce how much is consumed.
At an industry level, there are some major gains to be made by improving nutrient use efficiency, which makes immediate sense. On average over 80% of nitrogen and 25-75% of phosphorus consumed end up lost to the environment, wasting the energy used to prepare them (which collectively makes up 2% of global energy use) and causing pollution through emissions of the greenhouse gas nitrous oxide and ammonia to the atmosphere, while nitrate, phosphate and organic compounds are also lost into the water.
The United Nations has a goal of a 20% relative improvement in full-chain nutrient use efficiency by 2020 that would save about 20 million tonnes of nitrogen per year. It would also deliver an estimated improvement in human health, climate and biodiversity worth around $170 billion per year.
To do this farmers need to think about the four 'R's of efficient nutrient use, while basing their applications on real science (rather than from a soil consultant with a vested interest in selling fertiliser). These are using the right source, the right rate, at the right time in the right place.
When these factors come together, you get a farm that requires less work, less spending and produces a higher yield with lower impact on the environment.
