Everything you need to know about turfgrass nutrition in 1 lectureMicah Woods, Ph.D.Chief Scientist | Asian Turfgrass Center@asianturfgrassseminar.asianturfgrass.com/2014_osu.html

10 October 2014HORT 314: Principles of Turfgrass MaintenanceOregon State University

The 1 minute version

• Apply the right amount of nitrogen

• Ensure soil pH is more than 5.5 and less than 8.3

• Ensure soil potassium is above 37 ppm (Mehlich 3)

• Ensure soil phosphorus is above 21 ppm (Mehlich 3)

1. If the grass is supplied with enough of an element, adding more of that element will provide no benefit.

The 1 lecture version

2. Don’t worry about the function of each element. Just make sure enough of each is available to the grass, and nature will take care of the rest.

3. The exception is nitrogen, which controls the growth rate and consequently the demand for other elements.

4. How does one find out if there is enough?

We need to know 3 quantities

L-93 creeping bentgrassIthaca, New York

1. How much of an element is

present in the soil?

2. How much of an element is

needed in the soil?

3. How much of an element does the grass use?

As the grass grows, and as it is mowed, nutrients are removed Kyushu, Japan

January GCM: www.gcsaa.org

http://www.paceturf.org/journal/new_and_improved_climate_appraisal_form

Element C3 grass

N 4%

K 2%

P 0.5%

Ca 0.5%

Mg 0.2%

S 0.2%

Macro and secondary nutrient content in grass leaves

bent & Poa annua may use 0.6 lbs N/1000 ft2/month in good weather Oregon, USA

3.1

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N K P Ca Mg SElement

Pred

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We need to know 3 quantities

L-93 creeping bentgrassIthaca, New York

1. How much of an element is

present in the soil?

2. How much of an element is

needed in the soil?

3. How much of an element does the grass use?

ReferenceMinimum Levels for Sustainable Nutrition

Soil Guidelines

The Minimum Level for Sustainable Nutrition (MLSN) Guideline is a new, more sustainable ap-proach to managing soil nutrient levels that can help you to decrease fertilizer inputs and costs, while still maintaining desired turf quality and playability levels. The MLSN guidelines were devel-oped in a joint project between PACE Turf and the Asian Turfgrass Center. All soil analyses were conducted at Brookside Laboratories, New Bremen, OH.

Nitrogen requirements are best determined based on turf growth potential, which incorporates

Course Management, p. 108-113, March, 2005).

September, 2014

MLSN Soil

Guideline

pH >5.5

Potassium (K ppm) 37

Phosphorus (P ppm) 21

Calcium (Ca ppm) 331

Magnesium (Mg ppm) 47

Sulfur as sulfate (S ppm) 7

http://www.paceturf.org/journal/global_soil_survey

The amount of fertilizer to apply is:

The amount we need

minus

The amount we have

The amount we need is:

the amount the grass will use (harvest)

plus

the amount we need to retain in the soil (MLSN)

The amount we have is:

the amount in the soil (soil test result)

Expressed as an equation, the amount of fertilizer (F) to apply is:

MLSN (lbs/1000 ft2) + Harvest (lbs/1000 ft2)

- soil test (lbs/1000 ft2) = F

Reference

©2014 PACE Turf, LLC 1267 Diamond Street, San Diego CA 92109 www.paceturf.org

Minimum Levels for Sustainable Nutrition

Soil Guidelines

The Minimum Level for Sustainable Nutrition (MLSN) Guideline is a new, more sustainable ap-proach to managing soil nutrient levels that can help you to decrease fertilizer inputs and costs, while still maintaining desired turf quality and playability levels. The MLSN guidelines were devel-oped in a joint project between PACE Turf and the Asian Turfgrass Center. All soil analyses were conducted at Brookside Laboratories, New Bremen, OH.

How the guidelines were developed

not poor performing turfgrasspH 5.5 - 8.5 to avoid aluminum toxicitytotal exchange capacity <6 cmol/kg

-tion (in ppm) of each nutrient that 10% of the soil samples fell below, but were still performing well. This 10th percentile value is the MLSN soil guideline shown above.

For more information, see the Facebook MLSN page at: www.facebook.com/mlsnturf

version 14091801

Nitrogen requirements are best determined based on turf growth potential, which incorporates

Course Management, p. 108-113, March, 2005).

September, 2014

MLSN Soil

Guideline

pH >5.5

Potassium (K ppm) 37

Phosphorus (P ppm) 21

Calcium (Ca ppm) 331

Magnesium (Mg ppm) 47

Sulfur as sulfate (S ppm) 7

How to convert between ppm and lbs/1000 ft2?

Adding an element as fertilizer:

1 lb/1000 ft2 will increase the top 4 inches by 34 ppm

0.1 lb/1000 ft2 will increase the top 4 inches by 3.4 ppm

As the plant harvests elements:

1 lb/1000 ft2 will decrease the top 4 inches by 34 ppm

0.1 lb/1000 ft2 will decrease the top 4 inches by 3.4 ppm

MLSN (lbs/1000 ft2) + Harvest (lbs/1000 ft2)

- soil test (lbs/1000 ft2) = F

let’s say we harvest 1.6 lbs K and

soil test K is 50 ppm

MLSN (37 ppm) + 1.6 lbs/1000 ft2

- soil test (50 ppm) = F

1.1 lbs/1000 ft2 + 1.6 lbs/1000 ft2

- 1.5 lbs/1000 ft2 = F

1.1 lbs/1000 ft2 + 1.6 lbs/1000 ft2

- 1.5 lbs/1000 ft2 = 1.2 lbs/1000 ft2

3.1

1.6

0.39 0.390.16 0.16

0

1

2

3

4

N K P Ca Mg SElement

Pred

icte

d U

se p

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000 (ft

2 )

seminar.asianturfgrass.com/2014_osu.html