a modern method for estimating turfgrass nutrient requirements
DESCRIPTION
This presentation is about nutrient availability, how we can ensure the grass is supplied with enough nutrients while at the same time ensuring that excess nutrients are not being applied. This involves an integrated look at plant use of nutrients, at fertilizer application, at soil nutrient levels, and leaf nutrient content.TRANSCRIPT
A Modern Method for Estimating Turfgrass Nutrient Requirements
Micah Woods, Ph.D.Chief Scientist | Asian Turfgrass Centerwww.asianturfgrass.com@asianturfgrass
2 April 2014Victoria Golf ClubVancouver Island Golf Superintendents Association
Penn G-2 creeping bentgrass Shanghai, ChinaWhat are we trying to do?
1. Ensure all essential elements are in adequate supply
perennial ryegrassChiba, Japan
2. Maximize nutrient use efficiency by applying the
minimum amount required
Penncross creeping bentgrassChiba, Japan
How do we accomplish 1) adequate supply &
2) maximum efficiency? Penn A-1 bentgrass, USA
Enough K No K
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?
Quantity 1 (amount present)obtained from soil test
Cornell University Nutrient Analysis Laboratory, New York
ReferenceNovember, 2012
Minimum Levels for Sustainable Nutrition
Soil Guidelines
Minimum Level for Sustainable Nutrition (MLSN) is a new, more sustainable approach 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 developed in a joint project between PACE Turf and the Asian Turfgrass Center. All soil analyses were conducted at Brookside Laboratories, New Knoxville, OH.
MLSN Soil Guideline
pH >5.5
Potassium (K ppm) 35
Phosphorus (P ppm); pH<7.5, Mehlich 3 18
Phosphorus (P ppm); pH<7.5, Bray 2 25
Phosphorus (P ppm); pH>7.5, Olsen 6
Calcium (Ca ppm) 360
Magnesium (Mg ppm) 54
Managing sodium and salts: In locations where poor quality irrigation
meet the guideline of <110 ppm sodium or <2 dS/m salts, MLSN guidelines and overall management practices may need to be
basis. For more informa
Quantity 2 (amount needed) obtained from MLSN guidelines
www.seminar.asianturfgrass.com/20140402_victoria.html
Quantity 3 (amount used) estimated based on applied nitrogen
Manilagrass (Zoysia matrella)Fukuoka, Japan
The amount of fertilizer ( F ) to apply is:
F = MLSN (g/m2) + Harvest (g/m2) - soil test (g/m2)
60
0 0
600
20
40
60
Soil Test AnnualPlant Uptake
FertilizerApplied
Remainingin Soil
K (p
pm)
60
−47.9 0
12.10
20
40
60
Soil Test AnnualPlant Uptake
FertilizerApplied
Remainingin Soil
K (p
pm)
60
−47.9 33.5
45.60
20
40
60
Soil Test AnnualPlant Uptake
FertilizerApplied
Remainingin Soil
K (p
pm)
8.96
−7.15 5
6.810.0
2.5
5.0
7.5
Soil Test AnnualPlant Uptake
FertilizerApplied
Remainingin Soil
K (g
m2 )
74.6
−1.6 0
730
20
40
60
Soil Test AnnualPlant Uptake
FertilizerApplied
Remainingin Soil
Ca (g
m2 )
The amount of fertilizer ( F ) to apply is:
F = MLSN (g/m2) + Harvest (g/m2) - soil test (g/m2)
“N supply was the primary determinant of turfgrass growth rate, plant nutrient demand, and nutrient uptake. Nitrogen uptake accounted for over 88% of uptake of all other nutrients. Uptake of P and K were strongly related to tissue N content irrespective of soil test levels.”
Kussow et al., 2012
ISRN Agronomy. Evidence, Regulation, and Consequences of Nitrogen-driven Nutrient Demand by Turfgrass.
Annual N estimates based on maximum monthly use of 3 g N/m2
14.3 g N/m2/year based on 30 year average temperatures (monthly)
16.1 g N/m2/year based on 2013 temperatures (monthly)
15.6 g N/m2/year based on 2013 temperatures (daily)
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www.seminar.asianturfgrass.com/20140402_victoria.html