Tuesday, 2 February 2016

Turfgrass fertilization is not that complicated.

I recent did a talk for the Western Washington GCSA about my experience using the MLSN (minimum level of sustainable nutrition) guidelines. I will be making a post about this soon. Today one of the attendees and speakers shared the following link about skipping granular fertilizer.

Kevin was right to assume that I would enjoy this article. I enjoyed it for probably the wrong reasons though, I find it baffling that there is still so much confusion when it comes to fertilizing grass on sand rootzones. I also find it interesting that they only talked with people who work for fertilizer companies and who's best interests are to sell more fertilizer. It's too bad they didn't include any independent turfgrass scientists in the discussion.

The main focus of my recent MLSN discussion was how simple the MLSN guidelines are and how they have helped me simplify my fertilizer use on my golf course. I talked for an hour about how I haven't applied much fertilizer but Micah Woods sums it up in one sentence.

"If your soil tests are above the MLSN guidelines, you can be confident that the grass is supplied with all of that element that it can use."
Of course it's not entirely that simple. A soil test gives you a snapshot of what is in the soil at that time. The grass will use the nutrients as it grows. Micah Woods describes it, "That's why I like to express the quantity of fertilizer to apply as a function of those three amounts: (a) the amount the grass will use, (b) the MLSN guideline, and (c) the soil test. Then a + b - c gives the amount of the nutrient to apply as fertilizer." Even then, it's way more simple than many will have you believe.

My talk discussed how there is a lot of fear when it comes to under-fertilizing but we are lucky in that we have the ability to take soil tests so that this doesn't happen. With a test we can confidently make decisions on what nutrient needs to be applied as fertilizer.

Here is my 2015 soil test results.

 Which I used to base my fertilizer applications on how much nitrogen I expected to apply.
As you can see there are a lot of zeros! Last year I only applied nitrogen and potassium as fertilizer on my greens and tees. On my fairways I have only applied nitrogen for the past 3 years but they are on native soil!

I was one of the first people to use the MLSN guidelines which I explained in my recent talk and will share in an upcoming post. Since then the experience has been 100% positive. If anything, applying hardly any fertilizer has made my golf course better and certainly hasn't made anything worse. We are always concerned about the consequences of under-fertilizing but I wonder what the consequences of over fertilizing are having?
Makes you think about the impacts of over-fertilization

I also haven't applied a granular fertilizer to my greens in over 3 years. I apply my fertilizer with my sprayer in very small quantities in a relatively high volume of water (2.5gal/1000 or 1000L/ha). I don't think that granular fertilizers are required and if anything they can result in you applying nutrients that aren't needed in your soil leading to waste because you can't change the nutrient ratio in a blended granular fertilizer.

The only time I've used my granular spreader in past 3 years.
The MLSN guidelines make it very easy to apply the right amount of fertilizer. Not too much, not too little. It's not complicated or risky. In the end it's all about results. You tell me if my lack of fertilizer use has made a negative impact on my golf course.