I thought it would be a good idea this week to sync my blog with the weather and since the spring is so bloody late coming, so is my blog… , but seriously, apologies for the delay.
I did say last week that the weather over the weekend just gone was looking pretty grim, but nothing prepared me for Sunday morning on Ravensthorpe reservoir, Northampton. I was trout fishing with my long-suffering boat companion, when she commented that it was drizzling (9.30), “Just a bit of low cloud I said”, “it looks like it’s turning to sleet” (9.45), “Stop being negative, nothing is forecast today, “it’s fair chucking it down with snow now” (9.50), “At least it won’t settle” says I, safe in the knowledge we’re in the middle of a reservoir. To my amazement, with the water being so cold and the flakes of snow, so big, it actually settled on the surface like an ice floe, “Fek this for a game of horses” said I (10.30) and retired home to bitch about the weather over Nespresso and Rundstykker (Proper Danish Brekkie)…..So you all have my sympathies for yet another trashed weekend leading to lots of course and I guess, grounds closures and I can assure you, what isn’t good for your business, isn’t good for the one I work in either. Most of you got a mix of rain, sleet and / or snow, around here we were about 26mm combined, but I know others got more…….so how are we looking for the week ahead ?
General Weather Situation
As predicted last week, this week we have a cold low in charge and that’s going to make life pretty grim when you consider the fact we’re only a couple of days away from the official start date for spring, i.e The Spring Equinox. (7.02 a.m on March 20th apparently). This is supposed to mark the day when day length and night length are approximately equal (hence the term Equinox meaning “Equal Night” in Latin), but it won’t feel like spring I’m afraid this week, but it will be relatively dry till the end of the week.
For Tuesday, we have a cold, dull start for many, though down in the west and south-west, you may see the sun early doors. From early morning we have a ridge of moisture moving into north-east Scotland and this will fall as snow across The Highlands throughout the day, particularly along the north-east coast down to Newcastle. There’s also a risk of wintry showers across The Irish Sea tracking along the Leinster coast and high ground of Wicklow during the morning and extending west to Connacht later in the morning and through the day and if anything intensifying to snow. For the south, I think they’ll be a risk of showers, some falling wintry in nature through the day, but particularly in the afternoon. Overnight into Wednesday, there’s again a risk of snow along the east coast, early doors, falling further south this time and pushing into The Midlands in the early morning and moving south down into Wales by lunchtime. Again there’s also a risk of snow in north Leinster / Connacht, tracking south through the day. Elsewhere it looks to be a dull, cool day with little sunshine as that cloud cover is pushed in off The North Sea on a cold, easterly wind. For Thursday, the wind swings round to the south-east / south and that’ll pick up temperatures a little, but unfortunately with that wind change comes moisture, and at this stage it looks like rain will push into the south-west of England / Ireland early doors and then move slowly and diagonally (\) up country through the morning to reach The Midlands by close of play Thursday. There’s a risk that this rain will turn to snow initially as it hits the cold, easterly air and if so, this will be later on Thursday night as temperatures drop. This rain front intensifies overnight and so Friday looks like being a very wet day at this stage for most areas of the U.K and Ireland, with heavy rain, falling as snow over the high ground and temperatures in the mid-single figures. Another feature will be the strong winds, southerly I think in nature, pushing that rain through the day to end the week very sodden indeed and possibly with heavy snow further north for Scotland as well. For Saturday, that rain should have cleared most areas, maybe hanging around over Ireland , the south-west of England and still falling as snow, particularly across the north-east of Scotland. As the winds drop through Saturday, so will the temperature, so Sunday looks cool / cold with possible overnight frost and still a risk of some isolated snow showers, so in a word, bad…
After yet another grim week, this week, are there any signs that spring is around the corner ?….well yes and no, but it’s not going to be a light switch transition this year…
Next week starts cool / cold with an easterly wind I think and frost likely for Monday. By Tuesday, that wind is swinging round to the south and pushing milder air up, so I think we’ll see a lift in temperature and a milder feel to the weather. But again, there’s a price to pay for mildness and this means more rain is likely, particularly on Tuesday p.m / Wednesday for Ireland with potentially heavy rain on the cards and rain for the rest of the U.K mid-week, before drying off for Thursday on the run up to Easter. Although we will have rain, I do think the temperatures will be a little better for this period and whilst there won’t be a sudden up turn (and actually we don’t want one really from a maintenance perspective with 2 x 4-day weeks on the bounce), it will feel more spring-like, with westerly winds. So that means we will start to get some drying as well as moisture, because loss of moisture by evaporation has been negligible this year. (See below)
Are we out of the woods yet ?, not really, as that trough pattern still remains, but the signal from the jet-stream is for a more westerly air-flow and this has to be better than what we’ve had of late…At this stage I think Easter will be sunshine and blustery showers, but that’s 12 days away and this may change….
A lot to speak about this week and that’s another reason why I didn’t want to rush my blog yesterday, because I know a lot of you, whether you’re greenkeepers or groundsman have some important decisions to make regarding maintenance work and with the weather not playing ball, it’s going to make life tricky, so let’s chat it through…
Spring Maintenance – The Pro’s and Cons
The issue with a lot of people is that scheduled maintenance week is sometime in March and with the hit of rainfall / snow and the lack of soil temperature, the discussion is whether it’s now going to be possible to do this or whether the type of aeration can be altered. I’ll start with golf, but I will touch on grounds maintenance to a degree as well. To support the discussion that follows, I’ve prepared some data to show a comparison of soil temperature, rainfall vs. E.T and growth potential in degree days, for 2013 y.t.d vs. the same period in 2012. As usual the data is from The Oxfordshire, so thanks again to Sean for sorting, much appreciated mate…
The Cause of the Problem 1 – Organic Matter Accumulation
The issue or cause of the issue goes way back to nearly a year ago now with the change to a wet weather pattern (April 8th, 2012). Last year as you’ll all remember we had frequent heavy rain that saturated the rootzone for long periods, this led to a lower oxygen status in the rootzone and coupled with lower than normal soil temperatures.(March – September 2012 average soil temp was -1.5°C lower than the previous year and the lowest for the same period since 2005) The end result of lowered oxygen status and lower temperatures was less microbial activity and ultimately less breakdown of organic matter, so a higher rate of accumulation. Dovetail into that, 2012 was a very hard year to topdress, i.e dilute surface organic matter and with a permanently wet surface, many clubs I know changed from hollow coring to solid tining, so they didn’t directly remove fibre, but of course if they top dressed after, they did dilute the fibre level with sand and decompact the rootzone to a degree. This also allowed gases built up by anaerobic bacteria (Hydrogen sulphide, methane, etc) to ‘vent’ and ultimately allowed the grass plant to breathe. There was also definitely less verticutting and scarifying carried out last year, so the net effect of reduced microbial activity, reduced organic matter removal and reduced topdressing was definitely increased organic matter levels in amenity turf.
Leap forward to now and we’ve already had less microbial activity this year so far, and although growth and hence organic matter production has been limited as well, we’re definitely carrying more surface fibre into the spring. Below is a recent soil sample comparison of 6 greens taken at 6″ sampling depth so the organic matter quoted isn’t just in the surface, it’s in the whole profile. The trend clearly shows an increase on 5 of the 6 greens tested in terms of rootzone organic matter and I’ve seen plenty like this..
The Cause of the Problem 2 – The weather so far this year…
Looking at the stats below, you can see why things have been hard so far this year in terms of maintaining grass, whatever the weather. Firstly, we have had very little growth potential in terms of leaf / shoot growth. As you can see from the graph below, grass hasn’t been able to produce top growth for more than 5 days since the start of January.
If we look at the growth potential closer in terms of growth-degree-days (GDD) greater than 6°C soil temperature, we can see that since January the 1st, 2013, grass has had only 30% of the GDD in 2013 than it had in 2012, for the same time period. So if you have thinning areas of turf, particularly those that are growth-limited anyway (shaded surfaces) due to poor light maybe, this is why.
Lastly, we can see that when we have rainfall at the moment, the surfaces wet up super -quick and of course, this is because the soil is saturated, but there’s another reason. Together with the lack of temperature and high rainfall / snow, we haven’t had drying days either, so the amount of moisture evaporated out of the soil into the air this year has been far less than 2012. How much less you ask ?, well last year at this time, we’d received 81mm of rainfall y.t.d, lost 54mm to evapo-transpiration (E.T), leaving a net surplus of moisture in the soil of 27mm. This year, we’ve received 138mm, lost 40mm to E.T, leaving a net surplus in the soil of 98mm. In other words, the soil contains 4 times the moisture level it did on the same day last year and even if it didn’t rain again and we lost 3mm a day to E.T, it would take a month to totally dry out, so that’s why we’re wet Mr Golfer / Player !
All this info is here
So let’s look at our options going forward…….
Why doing nothing ultimately costs money….
Building fibre in the surface and / or rootzone ultimately leads to a number of negative consequences and their effect is far reaching, here are some, but not all of the issues related to organic matter accumulation….
- Excess surface fibre leads to the plants root system being concentrated in the surface of the sward (Bridged Rooting). As such it is susceptible to environmental stress from water-logging or droughting out, so the grass cover suffers leading to a poor playing surface. These roots are also inefficient at nutrient uptake and so fertiliser longevity is compromised once the nutrient has moved past the surface roots. This leads to ‘light switch’ tendencies, i.e one minute the surfaces look fine, the next, they are yellowing off / thinning.
- Excess surface fibre will swell when wet and effectively ‘cap’ the surface reducing water movement from the surface to the rootzone below. This manifests itself as a soft surface, prone to foot-printing and also puddling / flooding after low amounts of rainfall, so more course / ground closures due to reduced playability.
- Increased pathogen activity – This costs money plain and simple, as a wetter, more stress-susceptible surface, is a calling card for Fusarium, Dollar Spot, Anthracnose Foliar Blight, Anthracnose Basal Rot, Fairy Ring, Thatch Collapse, Plant Pathogenic Nematodes to name but a few. All of these require treatment with expensive fungicides that cost upwards of £600 per hectare per application.
- Stress is also increased due to a decrease in the actual mowing height because the mower sits down in the thatch surface and so instead of cutting at a bench-set 4mm say, you may actually be cutting at <2mm. This puts the plant under more stress and heightens issues on the turf related to stress.
What’s to be done ?
Firstly, and I want you to understand I’m well aware of this one, as we move out of the scheduled aeration window during March, there are commercial implications associated with aeration. Clubs don’t want to see poor surfaces when the weather eventually obliges people to come out and play, they don’t want to suffer decreased revenue, especially on the back of what has been a very lean past 5 months and a lean 7 months prior to that. This I can totally understand, but doing nothing will ultimately cost money, when, depends on how bad the issue is, if it’s already reached unacceptable accumulation, you will be spending more money already keeping the surface clean from disease and ultimately you will be closing more than you should have to after rainfall.
For me, the first choice is to try and re-schedule the aeration so organic matter is removed and topdressing is incorporated, this is key. Even before that though, get some benchmarks established so you know the extent of the problem you have or may not have. That way you can also assess progress. Looking at the forecast, I can’t see that re-scheduling being this side of Easter, so personally I’d look to w/c 8th April onwards and let’s see what the weather is like then.
Next up is to look at changing the type of aeration to lessen the time the surface is affected. Two choices here, the first is to decrease your tine size if you are hollow coring and if practically feasible, tighten your block spacings so you still impact the same % of the surface as with a larger tine, but the tine holes are smaller and so the effect on play is diminished and heal time is quicker, that’s a fact. On my previous blog I posted a link to surface displacement with hollow coring / vertidraining / Graden work published by the ISTRC, but here it is again just in case you need it – ISTRC
The drawback is that smaller tines don’t eject as well, particularly when wet and the holes close up quicker and so getting topdressing into them effectively to fill the holes is harder, but those new contra-rotating brushes (see here) are smart bits of gear if you can afford to run to them (or hire them in)
The next option is to solid tine and topdress, so even if you aren’t removing organic matter, you are diluting it and most importantly you are providing channels for anaerobic gases to be vented. You’ll still need to tackle surface fibre and to do this you’ll need to wait for temperatures / active growth to commence and then scarify / verticut on a regular basis, ideally followed up by topdressing and brushing / drag-matting in, to work the dressing into the surface fibre and thereby provide channels for air and water movement.
For some of you groundsman out there that follow this blog, the job for some at present is to convert winter season pitches into cricket playing areas and I think here the weather will oblige, provided of course, your pitches are well drained. As we move into a southerly / south-westerly airstream, we will increase soil temperatures and that’ll allow the plant to generate new leaf after the cutting height has been reduced. I’d be targeting an application of low-temperature available fertiliser this week or early next week to stimulate growth and allow the transition to take place.
I’d just like to sign off by saying that I fully appreciate that all of your situations aren’t necessarily the same as the ones I’ve described, most likely they are even more challenging in terms of playing conditions, revenue streams, etc, but all I’m seeking to do is to chat through some options, simply that….good luck and all the best…