Interesting article about phosphorus, fertility and biodiversity
Ever wondered why that wildflower meadow you tried to make turned out such a mess? The answer almost certainly has something to do with soil nutrients. Not just any old nutrient either, but one in particular: phosphorus.
Fifteen years ago, a consortium of European ecologists looked at the relationship between soil nutrients and floristic diversity in 281 European meadows, and found a striking result: diversity was totally controlled by soil phosphorus (P). In areas with less than 5mg of P per 100g of soil, there were up to 60 different plants species in 100 square metres of meadow. Above that figure (up to 35mg), no meadow contained more than 20 species.
Not only that, the 20 species that were present were pretty dull; rare and interesting wildflowers were confined to low-P soils.
We can still identify soils that were last cultivated by the Romans because they have more phosphorus than soils that have never been cultivated.