Well we are nearly done with July and as the rain drops patter on my attic window I’m happy to hear it after missing the 10-12 mm everyone else got on Saturday 🙁
The times I’ve heard it said that the “rain just goes round us here ” in this or that location, but on Saturday, it did. Damn and blast.
It won’t be much today but every little helps at this time of year and it’ll keep the E.T down as well.
Mind you there’s an upside to every situation (well nearly every) and I enjoyed a reasonably dry session in the boat, got to see some beautiful cloudscapes and enjoy some cracking fly fishing as well, a tonic for the soul and a well-earned rest for my head I can tell you. This Covid thing rumbles on, economic necessity driving a relaxation of lock-down before we are really in a situation to go there. The consequences both here and abroad are plain to see and are worrying.
I think about this a lot as I’m sure we all do and a line from ‘The Stolen Child’, a poem by the great Irish poet, William Butler Yeats (a great favourite of mine and my dads) often comes into my head….
To and fro we leap
And chase the frothy bubbles,
While the world is full of troubles
And anxious in its sleep.
Think that’s me on my days off…chasing the trout in the frothy bubbles of wind lanes and quietly detached from a very troubled world till I pull my boat onto the mooring and check my phone. Ho hum….
I’ve posted this picture before when I marveled at the ability of Maize to establish in the driest of springs and then pile on the biomass through equally dry summers. Now I know why….
Reading an article from New Scientist recently answered the question of how Maize can be so good at growing in a dry climate. The article in the July 15th edition (I can always tell when my work-life balance is out of sync by how many editions of New Scientist I have yet to read !!!) discussed the phenomenal abilities of a plant called ‘Agave’ to grow in the driest and most arid of climates.
Never heard of it ? Well you’ve probably have experienced the effects of its main ingredients at some stage or another because it’s the plant that produces the main ingredient of Tequila ! (yuk!)
The article discussed the 3 photosynthetic pathways utilised by plants, C3, C4 and CAM and their relative merits. C3 plants include the cool season grass species we have in the U.K & Ireland, whereas species like Bemuda and Paspalum are C4 species and better able to utilise water and photosynthesise more efficiently. Agave goes one step further, as a CAM category photosynthesiser (Crassulacean acid metabolism) it only opens its stomatal pores at night to fix CO2 and keeps them closed during the day. This way is avoids water loss during the day and is more efficient at converting CO2 and conserving water. CAM photosynthetic plants include Agave, Aloe Vera, Cacti and many aquatic plants as well.
The first reason why I found this interesting is that I didn’t realise Maize was a C4 plant and that’s why it is able to grow so well during dry periods of weather. It also got me thinking that if climate change continues in the future will we see C4 grass species come to the fore in the U.K and Ireland or will we see genetically-modified plant species which have been converted to utilise C4 or even CAM photosynthetic pathways shape the future of agriculture and food production ?
Well that’s the way plant breeding is heading….taking one idea from nature and putting it into another plant species to improve it. Of course ‘the ignorants’ (and that includes the EU regulators by the way) will say this is a GMO plant and therefore ‘not fit for human consumption’…Ever heard of the Luddites ?….
I can’t recommend highly enough a subscription to New Scientist, it’s been a pillar of my life since my dad brought me it as a present for a spotty grunt of a teenager…It got me my first research job and thus set me on a path to where I am today…ahem….There is always something interesting in it for everyone, Techies, Scientists, even teenagers….treat your kids or your friends to a sub and watch them change 🙂
Click here for a link to the article, the whole content of which you won’t be able to read until you subscribe…
Onto the weather..
General Weather Situation
So as we can see from the GFS output above we have low pressure in charge and it’s pushing down a raft of heavy showers on a strong south westerly air stream which makes Monday cool, unsettled with plenty of rain for most areas. As I type this, the rain looks to have cleared most of Ireland but there’s some pretty heavy stuff over the north and heading into the west of Scotland. Similarly further south I’d see the first wave of heavy showers moving through this morning with more to come later. So an unsettled today for pretty much everyone, driest across Ireland and the east of England I’d say but maybe rain for the latter, later. With a south westerly air stream it will be mild so expect high teens to low twenties despite the cloud cover and rain, a recipe for disease I am afraid. Cooler over Scotland which I think will pick up some of the heaviest rain along with the north of England and North and Mid-Wales. It’ll be pretty windy today as well.
Onto Tuesday and that low pressure system is projected to be off the coast of Norway and will therefore exert less of an effect on our weather. I say less of an effect, but it will still pull down showers across the west and north west Scotland from the off on Tuesday and these showers will push into central Scotland and The Lakes through the morning. The departing edge of the low will also pull down some cooler north westerly winds on Tuesday so expect a slightly cooler day in those fresh to moderate winds. Through the day we will see a continuation of those showers across the north west of the U.K but further south it looks to be a reasonably dry and dull day with pleasant if not particularly high temperatures and some spells of sunshine between the clouds. Despite the north west wind direction I’d expect to see temperatures into the low twenties in the south of England. For Ireland and Scotland expect mid to high teens with a dry day for Ireland but on the cool side because of the strong north westerly winds there. Scotland lies closer to the low pressure system and here it’ll feel pretty cool with temperatures lucky to hit the mid-teens during the day with the ever-present cloud cover and rain showers.
No sooner than one low pressure departs than another tips our way as Wednesday sees a new Atlantic low pressure push rain towards Ireland whilst the U.K basks in transitional high pressure. So Wednesday looks to start dry for everyone but by the time we get to morning rush hour in Fanore, Co. Clare, the rain will be approaching the west of Ireland. By lunchtime that rain is into Co. Kerry but it’ll make slow progress thereafter and principally affect the south west, west and north west of Ireland through the course of the day. The reason for this slow progress is that the low pressure is butting up against high pressure sitting over the U.K and that’s what will give a pleasant day for the east of Ireland, England, Wales and Scotland for Wednesday. So calm and settled with temperatures in the mid-high teens (Ireland, Scotland) to low twenties (Wales and England), still with moderate winds from the north west pegging back the temperature, but otherwise pleasant 🙂
Thursday sees that rain across the west of Ireland push inland into the middle of Ireland and consolidate to bring heavier rain to some areas first thing on Thursday. This rain will track north and east, pushed along on strong south westerly winds due to the interface of the low and high sitting over the west of Ireland. Eventually reaching the west of Scotland by lunchtime. Away from the strong winds, cloud cover and rain, Wales and England will bask under high pressure from the continent which means light winds and rising temperatures pushing up into the low twenties during the day. The leading edge of that high will kiss the east coast of Ireland so you’ll pick up some nice warm temperatures across Leinster and down the coast to Cork. By tea time that rain has cleared most of Scotland but will still be washing the ears of Spring Barley on The Black Isle 🙂 So a dry, warm and settled end of the day on Thursday for everyone.
Closing out the week on Friday and we see that high pressure continue to push against the Atlantic low. This will force a peak of warm air up from The Med into the southern half of the U.K and Ireland pushing temperatures up into the mid-high twenties. Ireland will be a real east-west split with low pressure pushing cloud and rain across the west coast and then somewhere across The Midlands it’ll change to high pressure, less cloud and much warmer. For the U.K, it looks warm, dry, sunny and settled for the last day of July with long spells of unbroken sunshine. During the day the cloud cover will push eastwards across Ireland and into the west of England pushing some showers inland across Ireland. Now watching this weather dynamic through the course of the last week has been interesting. First off the low pressure was due to dominate the end of this week, then the pendulum swang to high pressure and hot conditions. Now we see it swing back the other way a little.
So the outlook for the weekend is mixed with that rain over Ireland pushing eastwards overnight across the U.K. I’d have thought that introducing moisture into a high temperature environment would be likely to trigger some thunderstorms along the way as well. So Saturday looks like starting off dry for Ireland save for some showers along the west coast, wet for the eastern half of England and Scotland but dry elsewhere. As we go through the day, the rain will move off east and it’ll brighten up from the west so a sunshine and cloud day for most on Saturday. Cooler as well with north westerly winds pulling down temperatures to the low twenties for England and Wales, with a return to mid-high teens for Ireland and Scotland. Sunday sees low pressure exert itself so a cooler, fresher day with north west winds continuing and a raft of showers forecast for Ireland. Some of these showers will push across The Irish Sea into Wales, England and Scotland. So a sunshine and showers start to August with high teens temperatures for all of us and some rain on Sunday. Some areas may miss these showers completely. Winds will remain on the fresh to moderate side and north westerly.
As you can probably see from the GFS output above, next week is currently projected to start unsettled with two low pressures calling the shots. With a southerly bias to the low pressure position we should expect to see rain across Ireland on Monday and this will push into Wales and the southern half of the U.K during the course of the day. This low pressure will be slow-moving so expect to see more rain across the southern half of the U.K on Tuesday., some of it possibly heavy. Wednesday sees that low pressure move away and leave behind some showers but its departure leaves the way open for a new Atlantic low to push in more rain on south westerly winds across Ireland during the course of Wednesday. This low will push heavier rain across all areas for Thursday before spinning round and doing it all again on Friday. In short, the start of August looks unsettled and on the cool side though I’d expect high teens and possibly low twenties between the lows.
So carrying on the theme from previous blogs comparing 2018 and 2020 from a soil moisture deficit perspective you can see the curves edge ever closer. As predicted by early August I’m pretty sure we will see 2018 move past 2020 from this perspective and it can only be welcomed. OK you might disagree if you’re on a holiday in the U.K or have one planned but for me a sunshine and showers summer is what we need this year to make up for the ludicrously dry spring. It does however change how we approach fertility or at least it should maybe ?
Summer granular fertiliser
When we have these cooler, wetter summers often characterised by spikes of rainfall, it can be tempting to just continue the way we normally do with liquid fertilisers, PGR’s and the like but we should remember there are consequences. Liquid feeding is a relatively inefficient process and particularly when we have cooler, wetter conditions with higher levels of leaching and slower plant uptake. Plant species like Poa annua will prolong their seeding process when they are ‘sitting’ at a low N leaf status and inadvertently sometimes we may be aiding this process by liquid feeding inefficiently. Cooler, wetter summers also tend to increase disease activity and this year we have seen an increased incidence of Waitea Patch, Fairy Rings, Take All, Microdochium and Anthracnose. Now nobody wants to generate silage by over-applying N, it is a intuitively counter-productive process with slow green speeds, increased water uptake and a thinner, more succulent leaf, prone to disease and less able to withstand wear, but there’s a middle ground here. A low N granular fertiliser with slower N-available forms mixed with some faster start materials will pick up weak greens quickly and grow out damage. If next week’s unsettled forecast turns out to be accurate, it would be a good time to get a product like this down if your sward is struggling a tad that is…I’m not in any way discounting the merits of liquid fertilisation, it is great at inputting low levels of N accurately and of course you have the facility to tankmix but there’s a time and a place for both liquids and granulars. In a cooler, wetter summer I think a mix of the two is best…
Surface organic matter trends…
An unwanted consequence of the lockdown period earlier this year has undoubtedly been an increase in surface organic matter (SOM) caused by a reduction in maintenance, an increase in mains water usage (as opposed to the more usual split between mains and hand-watering) and a lack of play. Going forward towards what normally would be summer aeration time for golf clubs, it is for sure not going to be an easy task to redress the balance particularly when you look at the loss of revenue clubs experienced earlier in the spring and are still experiencing today in some parts of our industry. Carrying out less intrusive but still effective aeration is probably going to be the name of the game this summer / autumn and I would strongly make the case for verticutting and topdressing to target any apparent accumulation combined with vertidraining to relieve compaction and to give the greens a chance to ‘vent’. Now not everyone is a fan of this approach and for sure, one size hat doesn’t fit all but I think Covid and the lockdown period gives us an opportunity to re-appraise our aeration process, Not least also because of the continuing issue numerous clubs are facing in relation to Leatherjackets and / or Chafers. Punching holes in the ground at a time of year grubs are moving to the surface to feed (spring) or adults are laying eggs (autumn) maybe isn’t going to be a way forward for us in the future unless we manage to get the situation under control with Acelepryn.
OK, you may say, so I’m carrying a little more surface organic matter (SOM) into the summer, so what, no big shakes….
Well to me it’s likely that the extra SOM will be costing you more in water, wetting agents and biostimulants as you are effectively managing a higher plant stress environment.
Recently I started doing some work comparing actual air temperature measured by a Davis Vantage Pro2 weather station (with a temperature – humidity sensor positioned at 2 m above ground) with soil moisture and temperature probes buried just under the surface organic matter layer at 25 mm.
The initial results are interesting but what really surprised me was how much warmer the soil temperature was at the hottest part of the day vs. the air temperature. Now, it has always been said that SOM heats up faster than the rootzone but I’ve never seen much published data on by just how much. It is worth pointing out that these results are from a high sand rootzone and that different soils will behave differently, dependent on the level of SOM and the air and water-filled porosity characteristics of the rootzone.
Here’s the data from a pretty warm day in July last week…..
The above graph shows soil and air temperature vs. E.T on a mm per hour basis.
Now we can see that during the early hours of the morning, the soil temperature was lower than the air temperature, at most 1 °C lower at 3:30 a.m. By 06:00 a.m the air temperature and soil temperature are equal and thereafter the soil temperature increased faster than the air temperature to a point where at 14:30 p.m the soil temperature was 28.5 °C vs. the air temperature at 24.2°C , some 4.3 °C higher !
Soil temperature continues to track higher than air temperature until around 22: 00 p.m when they reach parity again, so that’s 16 hours of a summers day when the soil temperature tracked higher than the air temperature. Quite an eye opener I think…..
Now at that temperature we know a plant species like Poa annua would be going under stress but if we just judged the situation on air temperature, we would still think we had some margin to go before this point and particularly if we calculated stress as a function of a decreasing Growth Potential reading as calculated by air temperature maximum and minimum.
So that makes me think that SOM is playing a more significant role in plant stress, maybe more than we perhaps thought in terms of its ability to increase temperature in the top 25 mm of the profile. Now we also know that SOM impacts on soil moisture availability but if we measure using a standard moisture meter we are actually measuring deeper than this at 50-60 mm. So all may seem hunky dory at 50 mm but in the top 25 mm we are heating up very rapidly and most likely undergoing hydrophobic conditions sooner than the zone below it.
Food for thought maybe ?
All the best