Park Grass photos

Have you heard about the Park Grass experiment? The one that started in 1856 with different fertilizer treatments applied to a hay meadow in England, with those fertilizer treatments applied year after year to see what happened to hay yields? The experiment that immediately produced an unexpected result of different species composition on the plots treated with the different fertilizers?

A long time ago—prior to the Civil War in the United States—Lawes and Gilbert¹ noticed that “the experimental ground looked almost as much as if it were devoted to trials with different seeds as with different manures [fertilizers].”

Now there is an interactive photo gallery by Sarah Perryman and Nathalie Castells-Brooke² showing each of the Park grass sub-plots in May 2022. I looked at this on my phone and on a laptop screen. The larger the screen the better.

Frank Rossi and I wrote The Park Grass experiment and the fight against dogma describing some of the key results from this experiment.

Some general conclusions are that nitrogen application reduces species diversity and favors the growth of grasses. That is, adding nitrogen reduces what turf managers would consider weeds. Rossi and I wrote that “another striking ecological observation is that adding lime, phosphorus, or potassium will increase the abundance of non-grass species.”

When you think about many of the general recommendations for turfgrass—to keep the soil pH neutral (close to 7) by adding lime, to apply complete fertilizers, to keep the soil well-supplied with P and K—these all cause an increase in weeds in a turfgrass stand.

If you are at all interested in this, I expect you’ll enjoy looking at the Park Grass photo gallery.