Saturday, 29 October 2016

Visualizing how the growth potential model changed the way I fertilize my golf course

In my last post I outlined how the amounts of fertilizer applied to my golf course has changed over the years due to adopting the MLSN guidelines. In this post I will show some cool animated charts that show how the way I fertilize has changed as I adopted the growth potential model. Special thanks for Micah Woods for making these cool animated charts with my data. Refresh the page if the animation doesn't repeat.

This first chart shows the monthly nitrogen applications to my greens side by side going back until 2008. As you can see, as time goes on  the rates get lower but they also get more consistent with less big spikes. Looking back 8 years I can't help but wonder what I was thinking! It is really too bad that I don't have growth rate data going back more than a few years.



You can see that in early 2012 I was on a similar track to what I would normally be on. That was until I came across this article about using growth potential to determine nitrogen rates based on temperature by Micah Woods from 2012. I started using growth potential in late 2012 but didn't get into a good groove until 2014. This was because in 2012 I was just starting out and in 2013 I had to add more fertilizer to help my greens recover from winter damage. Since then I have lost very little grass and fertilizing has been business as usual with no major variances from the growth potential model.

The next animation shows the same thing as the last one except the monthly amounts are transposed on top of each other so that you can more easily compare how the rates per month changed.


The chart below shows the cumulative amount of nitrogen applied to my greens over the years. As you can see, my total annual nitrogen rates are where I used to be at in May! This has had a big impact on thatch as well as the amount that we need to mow our greens in the spring. It has also helped us get a better quality of cut during the poa seed head flush each spring.


Thanks again to Micah for making these charts with my data. I find it interesting to look back at what I have done and to compare it like this.

Next up is to try and figure out what changes if any I plant to make for my fertilizer practices in 2017!

Tuesday, 25 October 2016

Visualizing how the MLSN guidelines changed the way I fertilize my golf course


In my last disease update I looked in depth at my nitrogen use on a month by month basis to analyze what I was doing to see if it was the cause of my disease issues. During this process I decided to compile all my fertilizer data going back until 2008. Sadly I cannot find any records from before then.

Greens

Looking at these charts it is clear that before 2012 and my adoption of the MLSN guidelines that I had no clue what I was doing as far as fertilizer goes. The rates of P and K are widely variable as I was undoubtedly trying to chase cations or something.... All I can do looking back is shake my head but at the time I didn't know any better. I was just following the fertilizer recommendations based on the faulty BCSR. What a waste. It's no wonder that MLSN made so much sense to me when it was released in 2012. Fertilizer didn't make any sense to me!

Since that time the rates of all nutrients applied to my greens has gone down. From a high in 2008 to a low in 2016 I have only seen conditions improve during this time.

Looking at the above chart it's very obvious when the MLSN guidelines came out. Instantly P and K were no longer needed to provide a "balanced" soil or push spring root growth or summer heat stress tolerance.

So what happened in 2013?


I had a rough winter where I lost a lot of grass on most of my greens. Shade, poor drainage and golfing on frosty turf all contributed to the disaster. Looking back it was this catastrophic event the allowed me to starting working to remove shade and improve drainage and make a big difference.

Regardless, I had to grow some grass and as this happened the first year after adopting the MLSN guidelines I had my doubts. My greens were mostly poa and the best way to grow poa is to fertilize the grass so that's what I did.

The past few years have been disaster free and I have never applied less fertilizer on my greens. Part of it is because of the MLSN and the rest is from adopting the growth potential model for timing fertilizer applications.

The physiological impact of making such a drastic change to the way you fertilize your grass is huge. Because I made such huge and drastic changes all at once I was a bit worried. If anyone in the future decides to make the change to the MLSN guidelines I would suggest comparing where the MLSN guidelines will take you and for the first year meet it half way. That way the changes are slow and you won't have a panic attack like I did.

As you can see, 2015 and 2016 have been almost identical as far as macro-nutrients are concerned. This is because the soil levels for K has fallen down to the guideline and I am now applying K to stay at or slightly above the guideline. The soil doesn't contain any excess K.

Soil P levels have gone up even though I have applied no P fertilizer. This is from the slow conversion of phosphite to phosphate as I understand it.

The following chart shows all the nitrogen applied per month per year. It's a mess of a chart but there is one clear odd one out. July 2010. Jeeze I never thought looking at fertilizer rates would bring up so many bad memories!

In June 2010 my best friend's dad passed away. I went away to his funeral and when I came back this is how my greens looked.


Long story short while I was away the greens were watered for 4 hours during the afternoon with temperatures in the low 30C range. That's when I learned about how grass can boil to death. Needless to say I wanted to get them back in good shape ASAP as it was the middle of summer and this required a lot of fertilizer.

Wow, I've had a lot of grass die on me over the years.... But since the winter of 2012-2013 we haven't lost any grass and this is because we have put less reliance on adding more fertilizer to make the grass healthy and more reliance on providing adequate fertilizer, sun, and drainage.

Fairways

The fairways at my course comprise about 10x the area that my greens do. Therefore any savings that I can make on my fairways will save me 10x as much money or more. My fairways are on native soil.

In 2012 I actually applied more N that the previous 3 years but make a huge reduction in the amount of P and K applied. At this time I was still applying fertilizer in a granular slow release form as this was the only way my equipment would allow me to spread fertilizer. I wasn't gutsy enough to apply granular nitrogen to my fairways so had to settle with a blended fertilizer.

In 2013 I got a big sprayer and started using urea because other superintendents had shared that they noticed no measurable difference between urea and slow release N except price. Since then I have taken soil tests on my fairways and they still have plenty of nutrients. We have only applied liquid applied fertilizer on our fairways since 2013.

Tees

We don't collect clippings on our tees therefore nutrient removal from mowing is less of a thing even though they are on a sand root zone. Again, I have no clue what I was doing back in 2009-2010. Must have been applying K for divot recovery or some crazy thing. Maybe I read that grass needs K at a 1:1 ratio with N. No clue.
In the end, the only thing that matters is that the tees have never been better or had less weeds (no herbicides used in the time of this data collection) and I have never spent less on fertilizer. Why apply it if it won't make things better?

It is especially concerning to see how much excess fertilizer I was applying back then that wasn't having a meaningful impact on the quality of our grass. The extra nitrogen was definitely having an impact on the quantity of grass as I have had almost no excess clippings to deal with over the past few years. We had one day in late August when growth rates spiked a bit due to heavy rains and most likely some soil mineralization. That was it and to think of all the effort we used to spend to try and reduce clippings with special mower attachments and endless mowing and blowing.

If you want to learn more about the MLSN I will be doing a talk with Larry Stowell from PACE Turf at this year's GIS in Orlando. https://www.golfindustryshow.com/gcsaa-education-conference/seminars/2017/mlsn-guidelines-and-growth-potential

Saturday, 22 October 2016

1 fungicide app per year. Is there more to wood ash than we think?

It's no secret that I try pretty hard to reduce the amount of pesticide required on my golf course. I've tried a lot of things and over the years have refined my IPM strategy to only do what makes a real difference. They cost a lot, the public perception of pesticide use is negative, and it is a fun challenge to try and work towards reducing the use of pesticides on my golf course.

Things that didn't make a significant impact have been removed from my program. This past summer I went longer than ever between traditional broadcast fungicide applications or about 192 days. In previous years I would consider 60 days something to be proud of. Even so, I still required spot applications of traditional fungicides to stop disease spread and track the disease pressure of dollar spot on my greens.

Recently I came across this tweet.
Holy Smoke! Rob is making my efforts look like a joke.

I know Rob, he's the superintendent at the golf course in Terrace, B.C. They have a similar climate as here except they have a true winter with regular snow which requires a winter snow mold fungicide. In the past 2 years Rob has only had to apply his snow mold fungicide applications, and nothing else as far as traditional fungicides go. This is despite having as little as one month of snow cover in the winter.

I have heard of others doing the same or similar things but they are in much more arid climates where they have more control of moisture on their grass. On the West Coast of Canada we are inundated with rain for most of the year which makes disease management a huge issue to deal with (if my blog hasn't made that obvious already).

This is why Rob's tweet above got my attention. It's no joke maintaining good grass in this climate without traditional fungicides.

So what is Rob doing that I'm not? Well, a lot of things but this is what he thinks makes the difference.

Oh boy, here we go. I've had run ins in the past with compost tea users. Those who use it haven't been able to show me in a meaningful way that it works and this post isn't here to debate compost tea. My biggest issue with it has always been that it costs so damn much and doesn't make a significant dent in fungicide or fertilizer budgets. This is especially evident for someone like myself who already has an extremely low budget for both fertilizer and fungicide on greens. A 25% savings in fertilizer on greens will only save me ~$60 a year.

I guess if it wasn't for compost tea, Rob wouldn't have stumbled across this discovery....so there's 1 benefit haha!

Another issue I have with Organic is that it usually comes with a compromise in quality. Not with Rob.
But Rob's approach is almost free. Now we are talking the same language!

He also shared these pictures of clear lines of suppression similar to what you would see with a traditional fungicide application. This really got my attention.
Or this on his tees.
So Rob has virtually eliminated the need for traditional fungicides while his turf is actively growing which is a big deal. And he hasn't just done it for one year, he has done it for two years. This suggests that it's not just good luck that is the result of his success. Further prodding Rob with questions revealed that he thinks that it is the ash and not so much the compost that is the reason for his disease management success.

I decided to do some internet research about wood ash.

Most of what I found had to do with the chemical properties of wood ash. It has varying amounts of plant nutrients and is used as a fertilizer in low pH soils as it has a very high pH. It seemed that everything that I could find had to do with either the nutrient content or the pH of the ash.

Then I came across some people who reported using ash to kill algae in their ponds. In some instances people report using 1 tablespoon of ash to treat a half acre pond! Wow that is a low rate for such a big impact. Surely this small concentration of nutrients and pH has no impact on that amount of water. It must be something else that is killing the algae or these reports are total BS.

Wood ash can also be used to make Lye or potassium hydroxide, a highly caustic product used to make soaps, drain cleaners and can be used to dissolve tissue. Yes it can be used to dissolve your flesh off your bones. Maybe this property is having some impact on the fungi? Hmmmm

Making Lye involves leaching ashes in water...exactly what could be happening when you put ash into a compost tea brewer. Maybe the combination of compost and wood ash has something to do with it?

Either way, it's worth taking precautions if this is the byproduct of putting wood ash in a compost tea brewer for a few days. Bottom line, be careful.

So with nothing to lose I have decided to give wood ash a try on my tees this winter. It's free, I have a ton of it (wood heating in shop), and it gives me something new to try and learn from. But in order to build off Rob's success I needed to know more so I decided to interview him to get all the goods. Big thanks to Rob for sharing so openly about what he is doing, this kind of attitude is what helps our profession grow and move forward.

Jason: What exactly are you applying to your greens?
Rob: We started with 8 cups (compost) and 8 cups (ash) and saw some improvement, went to 12 and 12 and have since backed to 10 & 10 (I measure out 10 cups of ash and it weighed 1.5kg (3.3 lbs)

Jason: How do you make it?
Jason: How big are your greens?
Rob: 122K sq ft of poa/bent

Jason: How often do you apply it?
Rob: Once a week with fert apps or less in the spring and fall when I don't apply much fert.

Jason: What spray volume do you spray it at?
Rob: 125 gallons does all greens and collars. (about 1 gallon per 1000sq ft or 3.8L per 100m2)

So he's applying about 12g ash in 3.8L water/100m2 every week. (0.4 ounces in 1 gallon per 1000 sq ft) With that rate I could apply it to fairways!

Jason: How did you come across this?
Rob: I just noticed that grass grows well after a spring burn so I tried it.

Jason: Do you think it is the biological aspect of the ash and compost combined or just the ash?
Rob: I've got our mix tested and very little biological benefits as I see it.

Jason: Do you apply it with other products?
Rob: I mix it with most ferts including Urea. Don't mix it with chelated calcium.

Jason: Do you think it's just the ash or other IPM practices as well?
Rob: I think the ash compost is the ticket. Our soil science has been worsening as my budget decreases. Greens pH as low as 5.3, low in many micros and high in hydrogen. Irrigation water that is so clean it strips nutrients

So there you have it. I will be playing with this on my tees this winter and will include control plots. I have already applied a heavy iron application 3 weeks ago which has knocked the fusarium back quite a bit. I will stop the iron and switch to the ash applications to see what happens. I will also do some applications on a few of my troublesome greens this winter along with control plots.
low tech compost tea brewer in action

Most of Rob's experience has come during the growing season as his course is covered in snow all winter. It will be interesting to see if it works at all during the cold winter months on my course. As he and I don't think it's the biological aspect of the ash or compost that is the reason for the control I think it could work even in the cold winter where the soil biology is slowed.

I am skeptical at this point but am open to the idea especially since it is free and will give me something to do this winter and maybe it will kill some grass! Something this easy and free just seems too good to be true. We all know that disease management involves a lot of factors and I am sure that Rob does a whole host of other things that result in his success. Will ash prove to be a viable disease management option for me? Stay tuned to find out!

Tuesday, 18 October 2016

Disease Update, You win some you lose some (mostly winning)


On the West Coast of Canada we are now well into the time of year where fusarium is the dominant disease on turf. Reflecting on the summer of 2016 I can't help but feel somewhat defeated by turf disease. I required a traditional fungicide for dollar spot for the first time in 4 years on my greens. While this has left me feeling down about my disease management plan this year a closer reflection shows that while I lost the battle to dollar spot, I won the battle with every other turf disease on my course this summer. Looking back at the data, the battles I have had in previous years, what other courses in my area were dealing with I can feel really good about my disease management this past year.

To recap the requirement of traditional fungicide on my course this year so far is rather easy. The last fungicide application of the winter was on Feb 22. From that time I was able to keep disease levels at acceptable levels until Sept 4 when I needed to take action against dollar spot. That is 192 days between fungicide applications. That is the longest interval I have ever had between traditional pesticide applications on my course so that is something for me to be proud of. Looking back at what happened I learned a lot of things that I think I can use to extend that interval further in the future.

During that long stretch I used products containing phosphite, silica, spot applications of traditional fungicide (about 10m2 worth) and selective fertilizer applications and cultural practices to successfully manage disease.

Dollar spot

As mentioned earlier I have successfully managed this disease without the need for traditional fungicides in the past few years. This year I was completely surprised to see it show up on my greens. I talked a lot about why I thought I had it this year in my previous disease update post but would like to add some further thoughts to why I think I got destroyed this year.
yikes!
This year I went through March-June without a traditional fungicide application for fusarium for the first time in my career. In previous years the need for fungicides during this time could have possibly knocked down the dollar spot inoculum to a point where it was easier to control with cultural practices later on in the summer.
sprayed on the left, not sprayed on right (obviously)

I first noticed the dollar spot in early June of this year but was able to manage it until early September. This is still pretty good in my opinion so I shouldn't get too beat up about it.

I came across this interesting tweet this summer.

It got me thinking about my nitrogen reductions over the past 2 years. Was I too low this summer? I talked about how I have been able to reduce my N rates without any detrimental impacts in this post but I wonder now if I am too low or my timing was off? One of the biggest impacts that using growth potential to schedule nitrogen rates has been disease management as described in this post. As can be seen in the above tweet, it appears that there is a sharp cutoff for nitrogen rates and their impacts on dollar spot in the summer.

the worst of dollar spot on putting greens
I decided to look at my N rates closer to see if they were the driving reason. As you can see below the amount of N I have applied (kg/100m2) in the month of August (blue line) has slightly risen over the years while my overall N applied until the end of August (red line) each year has gone down. So I am applying more N than ever during the time when dollar spot is active but less overall during the season.In Paul's tweet above he showed that rates of 0.27kg N/100m2 every two weeks had a significant impact on dollar spot. In August I applied 0.3 Kg N/100m2 or about half of what he showed to have a meaningful impact on dollar spot. Why then did I have success in the past?

Maybe I was right about the impacts of manganese on soil microbes as I mentioned in my previous disease update post? I also didn't apply any iron this summer which has been shown in some studies (another one here) to reduce the impacts of dollar spot. As can be seen in the following chart I have applied less and less iron to my greens over the years. hmmmm
I had stopped applying so much iron because of fear of iron cemented layers and the fact that it had a high EIQ which is a flawed method to determine the impacts of products used for pest control and something I no longer use. I have since brought iron back into my program and will keep a close eye on things to see if it is a viable option going forward. I started using iron on my hard hit tees and approaches this September and so far it looks to have slowed the disease progression.

Culturally speaking we rolled more this year than ever before but still not as much as I would like. We lost most of our staff in mid August so had to make big reductions in maintenance and this could have been a contributing factor why the disease finally got unmanageable.

Looking back on my year with dollar spot management I cant' help but feel defeated but I learned a lot and careful analysis of what I did will have me more prepared than ever next year. It was easy to get complacent over the past 4 years with my dollar spot management success and this year I learned more than ever when it comes to managing this disease without traditional pesticides.

Fusarium

This year was a beast for fusarium, or so I'm told. While I have never had so much success managing this disease, others near me had an epic battle on their hands with active disease almost constant this year with little to no reprieve in disease pressure.

I won't share the pictures that were shared with me here but trust me, it was not an easy year and this is why I am very happy with how little fusarium I had on my course this year. I came out of the easiest winter ever for managing fusarium and continued that success right up until Sept.

A quick recap of what I am doing where more can be found in previous posts linked in the post and elsewhere.

Chemically I spot sprayed to limit disease spread by mowers, and used regular phosphite and silica applications through the summer. I only mention silica because it could have impacts on fusarium but the scientific evidence at this time isn't that strong so use at your own risk eh.

Culturally I mowed as little as possible which entailed applying low amounts of N when fusarium was active, regular PGR (primo maxx) applications and rolled as much as possible to keep conditions good for putting. We did not verticut or groom at all and used solid front rollers on the greens mowers.

I kept N rates low and only applied Ca and K in July and August to limit the impacts that these nutrients can have on fusarium.

Image Credit: Doug Soldat, Turfgrass soil, nutrition and water specialist at the University of Wisconsin-Madison turf.wisc.edu Twitter: @djsoldat
Going forward this winter I will take a similar approach to managing fusarium but I will also be bringing iron back into my management strategy on approaches and tees as discussed in this post.

The grass is already growing very slowly and I have resumed regular spot spraying to prevent disease spread on the limited days that we do mow.
Growth rates are slowing down big time with only 2 required mowings in Oct.
I put out a traditional fungicide spray in late September as I had an important tournament and was pushing the greens more than I normally would. Since that time I have aerated the greens and have only required 1 spot spray to get the 100 or so spots on my 0.4ha of greens. September continues to be the most challenging month for fusarium as it is when I transition from high summer nitrogen to low winter nitrogen. This transition is when I ALWAYS see disease pressure act up. Maybe some timely iron applications in the future will help be get over this hump?

So far everything looks to be going as planned and I hope to repeat last winter's success to prove to myself that maybe this approach is worth looking into further.

Anthracnose

For the most part I didn't see much anthracnose on my greens this year until mid September. I had learned in previous years with managing the disease that it would only kill the poa in my mixed-stand poa/bentgrass greens giving a huge advantage to the actively growing bentgrass in the summer months.

I also learned that low K could make anthracnose worse so I applied all my K during the summer months to lessen the impact of anthracnose and fusarium which isn't' typically active at the same time as anthracnose (this summer was the exception see above!)
anthracnose thinning out the poa while the bentgrass quickly fills in the voids, nature's poacure
This strategy worked great and I didn't see the disease show up until I started limiting K applications in preparation for the fusarium activity in September.
the worst patch of anthracnose this Fall. I sprinkled in some bentgrass seed :)
I bought a fungicide for anthracnose just in case but didn't need to use it as I was able to put off any corrective action long enough until the weather became too cold for this disease to cause any more damage.

The best thing about the anthracnose this year is that most of the damage was on my 2 greens with almost no bentgrass. This afforded me the opportunity to sow seed into the thinned poa stand and I hope to have a good mixed stand of poa/bent next summer and consequently no need for corrective fungicides for anthracnose on my course. You have got to love mixed stands for disease management and pesticide reduction efforts.

Cyanobacteria

Not an issue. Despite the wet weather this disease didn't show up as I kept ammonium sulfate as a regular part of my fertilizer program and this seems to have helped out big time.


Silvery Thread Moss and the Moss Disease

Unfortunately I did not have a successful year culturing the disease that kills the silvery thread moss on my putting greens and my cultural efforts were not enough on their own to keep the moss to acceptable levels. Despite this I have taken no action for moss this year and will give it another shot next year before taking action with a herbicide.
Thatch collapse

I guess that is the problem with using naturally occurring beneficial fungi to do the dirty work for you. Sometimes the environmental conditions just aren't favorable for that disease's development. I saw some minor outbreaks this year but nothing significant as in previous years.

This is a similar issue that scientists have had when trying to develop this beneficial fungi into a product that super's can use to control moss. Sometimes it works, others it doesn't and this inconsistency is one of the biggest problems with bio-pesticides.

Thatch Collapse

I had this disease show up on my greens this summer but as of yet it has not caused any damage. With regular topdressing I seem to be able to keep the greens smooth and it is just a visual problem at this point as in the turf is a bit greener on the spots where this disease is active.


Total pest management cost

In previous years I used costs and EIQ to set goals for pesticide use. As EIQ is flawed I no longer use it so at this time I just have cost to compare vs previous years.

Last year I made a 30% reduction in the cost required to manage disease on my course. This year I am on track for a repeat of last year or a total yearly cost of about $3000 for disease management products for 0.4 ha (1 acre) of greens. We still do not manage disease anywhere else on the course except with the addition this fall of tees and approaches with iron sulfate. I am within 1% of my year-to-date allotment for traditional fungicides and phosphite and silica. As I have mentioned in previous posts, phosphite has fit into my disease management program without costing any additional funds. It basically replaces dollar for dollar traditional fungicides.

In closing I hope to build on what I have learned in previous years and build on the success to push the boundaries with pesticide reduction. Here's to a disease free winter! (knock on wood)