Fertilising what?

Grime on Lisbon stone - arguably including sulphur dioxide deposits

On Thursday I came across a fascinating article in Science Daily (see link below) about the possibility that the use of potassium fertilisers in flower-beds on top of a Belgrade fortress had contributed to a dark crust on the limestone of the structure itself.  Previously this effect has been thought to be more to do with the effects of sulphur dioxide pollution from coal-based industry and heating activities.  It is also an effect that occurs widely in the UK and the rest of the world and this research gives much-needed pause for thought on the very use of high levels of fertiliser in horticulture and also in agriculture.  It ties in with other effects on biodiversity and landscape that I have noticed in myriad locations.

This blog post is more complicated than some, so instead of weaving the point through the text as I often do, this time I am being very up-front about what it is about:
Economics – why use more than is absolutely necessary, surely having it leach away is throwing money literally down the drain?
Aesthetics – why make what we want to look good look anything but?
Practical common sense – why use too much and at the wrong time for it to benefit the intended recipient?

Guano buildup in Chile is a key source of fertiliser

What is fertiliser? Traditional farming methods have used all manner of extra nutrients to augment the soil in order to improve crop yield and give a better return on investment, of both time and money.  Horticulture is similarly interested in promoting growth and vibrant foliage with the aim of making plants grow for longer, flower for longer and, with some but not all, to help them live for longer. Manure, potash, lime dug from lime pits, all have been used widely but have been finite in their availability.  In recent decades far greater emphasis has been laid on the use of inorganic fertilisers, many of which are heavy with nitrogen and create ammonia as a by-product. These inorganic fertilisers are ready to be taken up by the plants immediately, which means very speedy results, but the risks of leaching loss are magnified as a result.