What can your soil tell you

Hi, this is Skip with Father and Son Pest and Lawn Solutions, and today, we're going to talk about soil samples. We're going to talk about why you should take a soil sample and how to take a soil sample and then how to interpret the results when you take a soil sample. Normally, when we take soil samples, it's because the grass, the lawn is not responding to the treatments that we're putting on there, specifically the fertilizer. So, what we want to do is we want to find out exactly what nutrients are lacking in the yard and we also want to find out what the pH is in the soil because pH is very important and because if it's too low or too high, it inhibits the grass from actually absorbing the nutrients that are in the soil.

So, if you have a lawn that's just kind of anemic, that's not growing well, maybe it's not in decline but it's just kind of sitting there and you're only having to mow it every two or three weeks and maybe the weeds are growing faster than the grass, things like that, might be a good idea to go ahead and take a soil sample and just kind of see what nutrients are available in the soil and what the pH is and go from there. What we have here, we have a soil and plant informational sheet. This is the type of form that you would fill out in order to do a soil sample. Now, we happen to use this company here, Waters Agricultural Laboratories. We like them, we think they do a good job. There's a lot of different companies that will do soil samples for you but this is the one we use.

The University of Florida will also do soil samples for you. All the forms are basically the same, but I just want to go through the form briefly and talk about how you'd fill it out for just a basic soil sample. Over here, you would just put your information in here. That one thing I'll mention is, these forms are used for all agriculture. So, whether some farmers will send them in if they're growing specific crops, but what we're doing is we're using them for turf grass. That's why it has like grower information, like that would be for a farm, a commercial agricultural company. So, it's not necessary to fill that out. But we have our name, address, our email address and phone number on here so that they know where to send the results when they get them.

And then over here, it talks about the sample identification. That's only for your benefit. Say for instance, if you had a sample from two different addresses, or maybe front yard and backyard, or maybe garden and lawn or something like that, the sample identification is just for your benefit so that when you get the results back, they'll tag the results with the identification that you give to them. Then you have here planned crop. Like I said, these forms are used for all types of agriculture. So, what we have here is we specify the type of grass that we're getting a sample for, whether it's St. Augustine, or centipede, or zoysia or whatever type of grass that we're growing, we put under the crop. And here, these are the different types of services that you can request, down here is the routine number one soil sample.

So, we just want the basic information. Some of these others are for more sophisticated crops or farms that want to get in a little deeper into the soil analysis. We don't need to get that deep with just when we're dealing with turf grass so we just do just a basic routine sample. And then, there's a couple other micronutrients that you can choose to have analyzed and we'd like to see how much zinc and manganese are in the sample because those are important micronutrients. So, we check those as well as getting the macronutrients which are the phosphorus and potassium. We go ahead and fill this out and then we collect a sample of the soil in a baggy, which I'll show you how to do here in a moment, and we send it off with this form.

What we're going to do here now is we are going to take a soil sample and I'm going to show you how to do that. It's really simple. All you do is you want to take maybe about a half a handful of dirt from three or four different places in the yard. I use a simple hand trowel to do that with and a baggy. We'll go over here and it really doesn't matter where in the yard you take it, I try to find places that are easier to dig like this place. The grass is a little bit declined but so it's going to be easier to dig. And I'll take about that much dirt from this area and I'll put it in the bag and then I'll walk over about 20, 30 feet. And you want to get the dirt, you don't want to go too deep, you want to get the dirt about two or three inches. Only go down about two or three inches because that's where the root zone of the grass is. Here's a little bit more.

And you want to put it all in the same bag and kind of mix it around so you can get an average of the whole area. It's not important to do different samples for different areas unless there was an extreme difference in the soil. Maybe one was full of trees and another one was completely clear of trees maybe that might have, might make a difference as far as the soil nutrient analysis. But most lawns, you can go around and take three or four different samples of dirt from the front and the back, mix them together in the bag and that's [inaudible 00:07:48]. I'm going to go one more place over here. So, I'm just going to go down about two or three inches and pull up a little bit more soil. You can see how much soil we had there. That's enough to do a soil sample for the lab to take that soil and analyze it. And if you get it from three or four different places in the yard and send it off to them, then that's perfect for what they need to analyze that and send you back the results.

After we have sent the soil sample off and they've had a chance to analyze it, they email us this form. I just want to go over this with you, give you an idea of what to look for when you get this form back. First of all, on the form that was sent in, there was the sample ID that you filled out. On this one, we just put in the address where we were sampling the soil or whatever it could, whatever you put in there then they'll put in this line here the sample ID whether it might be front yard, backyard, garden, whatever. Just, this is for your benefit so that you can identify what sample it is that they're sending you the results for.

So, the grower would be you and any identification that you put in here for yourself. This is the main body of the soil analysis. This is the biggest thing we want to look at. And it first starts out with the two macronutrients, phosphorus and potassium. As you can see, it's laid out in a bar graph and at first it shows you how much phosphorus is in there. And as you can see in this sample, it's very low. That's common for this area because we have sandy soil. The sandy soil is almost inert, it has very little macronutrients in it. And this is what this soil sample is displaying here, very, very little macronutrients. So, phosphorous is very low. That just gives you a general idea on the scale of how much phosphorus is in there. Then potassium, you can see potassium is just barely in the medium range and it's not up here is adequate. So, it still is low on potassium.

The two macronutrients that it was tested are low and medium but neither one of them are adequate. I also want to add in here the other, the third macronutrient that the turf grass uses is nitrogen. Now, nitrogen is not on this form because nitrogen is a water-soluble nutrient and it doesn't bind to the soil and it doesn't persist in the soil. So, anytime that nitrogen is added to the soil, say with fertilizer, that nitrogen just, it's either quickly absorbed by the turf grass or it filters on down through the soil and it doesn't remain there. So, they don't test for nitrogen in a soil analysis, they just test for the two macronutrients that stay in the soil which are phosphorus and potassium. Now, we have the micronutrients that we asked to be tested.

Now, they are well in the range. There's no problem with them being very high like this, it just means that there's a lot available but none of it is going to hurt the grass if it's high or very high. We notice over here that's magnesium, calcium, zinc, we also notice over here, manganese is very low. So, we just want to take that into consideration and when we go to choose our fertilizer, choose a fertilizer that has the micronutrient manganese, a significant amount in it, so that we can bring this number up too because that's an important nutrient for the grass. Now, the other thing that we want to look at here is the soil pH because that's very important when it comes to the grass, actually grabbing a hold of and utilizing these nutrients down here. The soil pH here is 6.2. Now, that's not too bad.

The target pH for turf grass is usually between 6.5 and seven. So, 6.2 isn't too far off. It does recommend down here that we apply a little bit of a lime to the yard just to bring it up slightly. You want to look at the soil pH and see if it's below 6.5, you might need to add a little bit of lime to the yard to bring that pH up. Now, down here are the recommendations for the nutrients and all the recommendations are put in pounds per thousand square feet, pounds of product or pounds of nutrients per thousand square feet. So, it's recommending 18.4 pounds of lime per thousand square feet which really isn't a whole lot of lime. Sometimes we see recommendations of lime up into 50, 60, 70 pounds of lime per thousand square feet. That's when the pH is really low.

18 is really not too bad. It's recommending nitrogen be applied at 4.6 pounds per thousand square feet, phosphorus at 1.8, potassium at 2.3 pounds per thousand square feet. And then the micronutrients here, remember we said manganese was really low, so it's recommending just about a quarter pound of manganese per thousand square feet be applied to the lawn. So, when you choose your fertilizer, you want to compare it, the formulation of the fertilizer with these numbers here that it's recommending and choose it accordingly. And then if you choose to put out lime, put it out at that rate.

The rest of this is it just kind of shows the breakdown of the different quantities of fertilizer. And there's some other information in here that, again, if you want to go really deep into the scientific chemistry of the soil, you can. We don't do that for our purpose is because we just want to look at the nutrients and we want to look at how much is there and then basically how available those nutrients are based on the pH. That's mainly what we look for and if you send off a soil sample, you'll get something like this back and that's how you interpret it.