I forgot this one too

Figure 4 from Drew’s classic article on localized nutrient supply to roots.

When I put together a list of articles that are not about greenkeeping, I forgot a couple that I really should have put on that initial list. One of those is Grime’s article about three primary strategies in plants.

Another is Drew’s Comparison of the effects of a localised supply of phosphate, nitrate, ammonium, and potassium on the growth of the seminal root system, and the shoot, in barley. Roots proliferated in zones with higher concentrations of nitrogen and phosphorus. Figure 4 is especially clear in showing these dramatic results.

This root response to nutrients has some relevance to turfgrass establishment, and to turfgrass maintenance.

As I was reading Drew’s article about localised nutrient supply again, I came across a sentence that struck me as relevant to another topic. That’s the complete lack of response to K fertilizer, even when soil test levels suggest the grass should require K, in some sands. The mechanism is K supply from minerals in the sand itself, obviating any requirement for potassium fertilizer. Bier et al. explained this in A long term evaluation of differential potassium fertilization of a creeping bentgrass green.

What’s the relevant sentence from Drew? This one.

“Potassium deficiency had the least effect on shoot growth and tissue concentration, and the total amounts of potassium per plant were greatly in excess of seed content, possibly reflecting the uptake of traces of potassium released from the sand.”

That didn’t stand out to me when I was studying Drew’s article in graduate school, but it does now.