research

On sand putting greens, it is. The problem caused by sodium is a reduction in the downward movement of water in soils. This is caused by the deflocculation of clay in the soil.

There is a fine article by Karcher and Richardson in GCM about the effect of wetting agents. In the article, they point out something important: It is often stated that some wetting agents move water rapidly through the root zone while other products retain considerable moisture near the surface, but the data to substantiate such claims is limited.

When it comes to fearmongering in turfgrass, I’m not sure there is a bigger one than bicarbonate (HCO3-). One often hears of supposed problems associated with bicarbonate. I’m still waiting to see a soil or turfgrass problem associated with this ubiquitous anion.

I measured soil moisture and surface hardness on three fairways, approaches, and greens at a golf course in Thailand in September 2014. The fairways and approaches at this site are seashore paspalum on a sandcap.

In the Global Soil Survey (GSS), we looked at the soil nutrient levels in soil that was specially selected as being from areas where the grass is growing well. The first year of GSS data are available here.

This is no secret among turfgrass scientists—there isn’t a lot of good justification to support what we call conventional guidelines for soil nutrients in turfgrass. And by that, I mean the conventional guidelines are broken.

Fairy ring symptoms, 8 green, August 2013 In 2013, at the KBC Augusta golf tournament, there was some type 2 fairy ring on the 8th green of host Keya Golf Club.

Does adding more potassium improve drought resistance? This article by Rowland et al. takes an in-depth look at that important question. They looked at bermudagrass (Tifeagle and Tifdwarf), seashore paspalum (SeaDwarf), and zoysia (PristineFlora) grown in a USGA sand rootzone.

Doug Soldat reports on descreased pink snow mold associated with low soil potassium. First he describes the study: In 2011, we began a trial to attempt to identify the lowest level of soil potassium that would still provide high putting green quality.

Update: I’m adding a note here today (21 Nov 2017) to correct and clarify about these data. Mike Richardson pointed out to me that the “differences from plots irrigated to field capacity 2X or 6X / wk were small and not significant” in this experiment.