Pounds of Limestone to Add

per 1000 sf to Raise Soil pH to 6.5


Original pH                       Sand                       Loam                     Clay

Pounds of Elemental Sulfur to Add

per 1000 sf* to Reduce Soil pH to 6.5


Original pH               Sandy Soil                Clay Soil 

With the chart above, it is easy to see how improper pH levels can effect soil nutrient uptake by the grass plant.  The old saying among farmers is if you don’t have a proper pH, don’t waste your money on fertilizer.


Although the chart shows optimum soil pH around 6.4, research has shown that turf does the best around 6.0. 

Pounds of Gypsum to Add per 1000 sf

to Reduce Soluble Salts to Recommended Levels


Original Salt Levels                             Pounds of Gypsum

                 in Parts Per Million                                   per 1000 sf 

2,500

1,800

1,250

700

550

320

230

160

80

40

7.5

8.0

8.5

10-15

25-35

35-50

20-25

35-50

40-50

4.8

5.0

5.2

5.4

5.6

5.8

6.0

6.2

6.4

85

75

65

55

45

35

25

15

5

140

125

110

95

80

65

50

35

15

200

175

150

125

100

80

60

40

20

Click here for printable version of the charts above.

*The recommended rates for sulfur are only for bare ground application.

If applying on existing turf, rates should not exceed 2-3 lbs./1000 sf

If you are confused by all the different slow-release nitrogen sources that are available, you aren’t alone.  Below I have provided some information on 5 common sources of slow-release nitrogen.


MESA


Meth-Ex & IBDU


Urea-Formaldehyde (UF)


Sulfur-Coated Urea (SCU)

Probably the most frequent question I get is about the application rates.  A customer will call and tell me they need to apply 1 lb. of nitrogen per 1000 sf.  Because they don’t do it often enough, they forget how to figure it out.  Below are some examples that will hopefully help.  However, you are always free to call and ask.


It also important to know conversion information or have that information handy.  Click here to view a printable version of Conversion Information.


1st number of the analysis -  Nitrogen

2nd number of the analysis - Phosphorous

3rd number of the analysis -  Potash


Remember that a fertilizer analysis is given in percentages.  Take 10-10-10 for example.  If you have a 50 lb. bag of 10-10-10, you will have 5 lbs. of nitrogen, 5 lbs. of phosphorus and 5 lbs. of potash in the bag.  50 lbs. times 10% (.10) = 5 lbs.


Using 18-18-18, take 50 lbs. times 18% (.18) = 9 lbs. each, nitrogen, phosphorus and potash in the bag.

Square Feet per acre:  43,560 sf or 43.56 thousands (43,560 divided by 1000)

Pounds needed:

1 pound of nitrogen per 1000 sf needed.

1 lb. times 43.56 = 43.56 lbs. of actual nitrogen needed per acre.

Fertilizer being used:

Let’s say you are using 18-24-12.  The first number is the % nitrogen in the blend - 18% (.18).  Take your nitrogen needs from above (43.56 lbs.) and divide by 18% (.18) = 242 lbs./acre 18-24-12  needed to get 1 lb. nitrogen per 1000 sf.

2nd example:

Now try an example using 26-4-18 and apply 1-1/2 lbs. of nitrogen per 1000 ft.  Take 43.56 times 1.5 lbs = 65.34 lbs. of actual nitrogen per acre needed.

65.34 lbs. divided by 26% (.26) = 251.30 lbs./acre

26-4-18 needed to get 1 lb. nitrogen per 1000 sf.

3rd example:

What if a soil test result shows that you need to apply 2 lbs. of phosphorus per 1000 sf.  The second number in a fertilizer analysis is the phosphorus level.  The third number is the potash level.  You are using 18-24-12 as your fertilizer source.

In this example, the phosphorus level in the blend is 24% (.24).

First, take 43.56 and multiply by 2 lbs. = 87.12 lbs./acre of actual phosphorus needed.

Divide 87.12 lbs. by 24% (.24) = 363 lbs./acre needed of 18-24-12.

4th example:

When you apply 363 lbs. of 18-24-12, how much nitrogen and potash are you applying?  We already know you are applying 2 lbs./1000 sf of phosphorus from example 3 above.


363 lbs./acre of 18-24-12

363 times 18% (.18) = 65.34 lbs. of nitrogen per acre or 1.5 lbs per 1000 sf.

                           

363 times 24% (.24) = 87.12 lbs. of phosphorus per acre or 2.0 lbs

per 1000 sf.

                           

363 times 12% (.12) = 43.56 lbs. of potash per acre or 1.0 lb. per 1000 sf.


Click here for printable version of examples above


Fertilizer Analysis

Pounds of Product

per 1,000 sf (1)

per acre (2)

10-6-4

14-1-11

16-4-8

18-24-12 w/SCU

19-0-19 w/MESA

20-0-5 w/MESA

21-0-0

24-4-6 w/MESA

26-4-18 w/SCU

29-3-5 w/SCU

32-0-6 w/Meth-X

34-3-11 w/SCU

39-0-0 (SCU)

46-0-0 (urea)

10.00

7.15

6.25

5.55

5.25

5.00

4.80

4.20

3.85

3.45

3.15

2.95

2.60

2.20

435

311

272

242

230

218

208

182

168

150

136

128

112

95

(1) Amount of product needed to apply 1 pound of nitrogen per thousand square feet. 


(2) Amount of product needed to apply 43.5 pounds of nitrogen per acre. To determine the amount of product needed to deliver 1 pound of nitrogen per thousand square feet, divide 100 by the first number in the fertilizer ratio. For example, for 16-4-8 fertilizer, divide 100 by 16. The result is 6.25 pounds of product per thousand square feet.

Several times a year, I get the question asking what texture makes the best soil.  The answer isn’t as easy as one would think.  It all depends on what the soil is being used for.  In this case though, let’s assume that it is going to be used to establish turf for a home lawn or commercial property, not necessarily an athletic field.


The relative proportion of various grain sizes in a soil is called texture.  To describe texture, names such as loamy sand, silt loam, clay loam and silty clay are used.  You can see these categories in the soil texture triangle above. 


The best soils are generally those that contain 10-20% clay, with silt & sand in approximately equal amounts, and a fair amount of organic matter.  Therefore, a “loam” soil is considered a very good soil. 


What is a fair amount of “organic matter”?  For establishing and maintaining turf, I prefer soils with 3.0-4.0% organic matter.  Levels below 3.0% tend become more compacted, holding less moisture and making it more difficult to maintain a healthy turf, particularly during stress periods.


Below I talk about how to raise the organic matter in soils with low levels.  It can get a little complicated, depending on the compost being used and the depth that the compost is being worked into the soil.

Adding compost to existing soil or to soil being applied to an existing site is very common.  Many of the soils that we are working with in the Mid-Atlantic region are low in organics and need to be amended.  The question is, how much do you need to add.


Let’s say that you having and existing soil with an organic matter of 1.0%.  The spec calls for you to bring the organic matter level to 4.0% in the top 4” of soil.  How do you figure out how much compost to add per acre? 


Below I have given some amounts of compost needed to bring soil up to 4.0% organic matter.  At some point, I will attach an Excel file that will allow you to plug in your parameters and get your answer immediately. 

In many situations, it is impossible to incorporate compost into the existing soil.  Most frequently you have an existing stand of turf and do not want to destroy it.  However, soil test results show that the organic matter is low and needs amending.  You can accomplish this by top-dressing compost over the top.  Depending on how low the organic matter is, you may need to top-dress a 1-2 times per year for several years to get the desired results.


Below are compost requirements for various depths of application.  Keep in mind that you should not apply more than 1/2” on existing turf.

Depth of Compost Desired

Amount of Compost Needed Per Acre

1/4”

3/8”

1/5”

3/4”

1.0”

1.5”

2.0”

34/yds

52/yds

68/yds

102/yds

136/yds

205/yds

270/yds

% Organic Matter

in Existing Soil

Depth of Soil

to Amend

Amount of

Compost Needed

2”

3”

4”


2”

3”

4”


2”

3”

4”


2”

3”

4”


2”

3”

4”

62 yds/acre

92 yds/acre

124 yds/acre


52 yds/acre

79 yds/acre

105 yds/acre


44 yds/acre

66 yds/acre

88 yds/acre


35 yds/acre

52 yds/acre

70 yds/acre


27 yds/acre

40 yds/acre

53 yds/acre

% Organic Matter

Required by Spec

4.0%

4.0%

4.0%


4.0%

4.0%

4.0%


4.0%

4.0%

4.0%


4.0%

4.0%

4.0%


4.0%

4.0%

4.0%

0.5%

0.5%

0.5%


1.0%

1.0%

1.0%


1.5%

1.5%

1.5%


2.0%

2.0%

2.0%


2.5%

2.5%

2.5%

Below is a lot of information about fertilizers, compost, lime requirements and more.