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Discussion Classes. Blue Course Green. Analysis. general deterioration of #4 green. shade from trees and tower. general deterioration of #4 green. shade from trees and tower. poor air circulation from trees and shrubs. general deterioration of #4 green. shade from trees and tower.

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Discussion classes

Discussion Classes

Blue Course Green




shade from trees and tower

general deterioration of #4 green


shade from trees and tower

poor air circulation from trees and shrubs

general deterioration of #4 green


shade from trees and tower

poor air circulation from trees and shrubs

general deterioration of #4 green

concentrated traffic between trap and green


shade from trees and tower

poor air circulation from trees and shrubs

general deterioration of #4 green

concentrated traffic between trap and green

poor internal and surface drainage


shade from trees and tower

poor air circulation from trees and shrubs

general deterioration of #4 green

concentrated traffic between trap and green

poor internal and surface drainage


shade from trees and tower

poor air circulation from trees and shrubs

delicate turfgrass

hot, humid microenvironment

general deterioration of #4 green

O2-deficient rootzone

concentrated traffic between trap and green

poor internal and surface drainage


Shade effects

QUANTITATIVE

reduced photosynthetically active radiation (PAR)

QUALITATIVE

photomorphogenetic response due to phytochrome

Shade Effects


Effect of reduced par on net photosynthesis
Effect of Reduced PAR on Net Photosynthesis

Light compensation point:

  • PAR intensity at which photosynthesis = respiration

  • No net exchange of CO2 & O2

  • Higher in C3 species

    Light saturation point:

  • PAR intensity at which additional light yields no increase in photosynthesis

  • Higher in C4 species


Red and blue light
Red and Blue Light

Photosynthetically active wavelengths include:

  • red light at 600-700 nm.

  • blue light at 400-500 nm.

    Other wavelengths are:

  • green light at 500-580 nm, which is reflected.

  • far-red light at 700-770 nm, which is transmitted.


Far red light
Far Red Light

  • PAR (red & blue light) intensity are reduced by shading.

  • Light transmitted through tree canopies comes through at longer wavelengths, including far red light.


Phytochrome
Phytochrome

Pr Pfr

Pr - blue pigment that absorbs red light, converting phytochrome from the inactive form (Pr) to the active form (Pfr).

Pfr - olive-green pigment that absorbs far-red light, converting phytochrome from the active form (Pfr) to the inactive form (Pr); this conversion also occurs slowly in the dark.


Phytochrome1

Active (Pfr)

Inhibits stem and leaf elongation

Promotes tillering

Inactive (Pr)

Promotes stem and leaf elongation

Inhibits tillering

Phytochrome


Other shade effects
Other Shade Effects

  • Thinner leaves and cuticles

  • Shallower rooting

  • Reduced carbohydrate reserves

    A “shade” turf is thus more delicate and less tolerant of wear, disease, and environmental stresses.


shade from trees and tower

reduced PAR and inactive phytochrome

delicate turfgrass

reduced tolerance to environmental stresses

general deterioration of #4 green


Poor air circulation
Poor Air Circulation

  • Closely planted trees and shrubs restrict air flow, resulting in a warmer, more humid microenvironment.

  • As a consequence, disease pressure is greater.


Wind effect
Wind Effect

Wind moves parcels of air from the turf and incorporates them into the larger volume of air above it.

Thus, the accumulation of heat and humidity are dissipated.


Moisture
Moisture

Moisture accumulation within a turfgrass canopy comes primarily from an evaporative process, called transpiration.


Transpiration
Transpiration

Water is absorbed by roots, translocates upward, and accumulates as films of moisture on internal leaf cells.

Water films evaporate and exist the leaf through pores, called stomates.


Boundary layer
Boundary Layer

Water vapor exiting the stomates accumulates in a layer of humid air immediately around the leaf.

With the development of boundary layers around all leaves, the environment of the turfgrass canopy can become quite humid.


Wind effect1
Wind Effect

With moderate air movement across the turf, however, the humidity of this environment can be substantially reduced.

And the potential for disease is proportionately reduced.


shade from trees and tower

poor air circulation from trees and shrubs

reduced PAR and inactive phytochrome

allows build-up of temperature and humidity

delicate turfgrass

hot, humid microenvironment

reduced tolerance to environmental stresses

increased disease potential

general deterioration of #4 green


Poor drainage

Surface Drainage

Reflects the ease with which water can move downslope.

Reflects access to catch basins through which surface water can be removed from a site.

Internal Drainage

Reflects the ease with which water can move through the soil matrix.

Reflects the presence or absence of obstacles (e.g., pans, layers) to internal soil water movement.

Poor Drainage


Surface drainage
Surface Drainage

To the extent that water falls at a rate in excess of a turf’s infiltration capacity, the excess will flow downslope and accumulate in depressions.

Catch basins situated in depressions can remove surface water and conduct it to drain lines or elsewhere.


Internal drainage
Internal Drainage

Water moves through the pores permeating the soil matrix.

The larger the pores, the faster the movement of water through the soil.


Soil water
Soil Water

Water movement from a saturated soil is from the macropores and is due to gravity; thus it is called gravitational water.

Water in the mesopores and micropores is called available and unavailable water, respectively.


Soil aeration
Soil Aeration

As water drains from the macropores, O2 is drawn in and CO2 and other gases are liberated from the soil.

A favorable relationship between O2 and CO2 in the turf rootzone is thus maintained.


Soil water movement
Soil Water Movement

Therefore, the rate at which water moves through the soil reflects its porosity and pore-size distribution.

Soils with a high proportion of macropores (i.e., coarse textured soils) conduct water more rapidly than finer textured soils.

As the surface dries from ET, water moves up from lower regions of the soil.


Water potential y w
Water Potential (Yw)

YW is a measure of the energy status of water; as free standing water has no energy, its YW = 0.

Soil water potential is symbolized by YSW

The components of water potential are: matric potential (YM), osmotic potential (YO), and pressure potential (YP).

YSW is measured in units of pressure, including bars and Pascals; 1 bar = 100 kP or 1 cb = 1 kP.


Matric potential y m
Matric Potential (YM)

This reflects the amount of water retained by the soil matrix.

As this amount declines, the water films surrounding soil particles become thinner and are held more tightly, and YW decreases correspondingly.

  • At saturation, YM is near 0.

  • At field capacity, YM = -0.1 to -0.33 bar (-10 to -33 kPa).

  • At the permanent wilting point, YM = -15 bar (-1500 kPa).


Osmotic potential y o
Osmotic Potential (YO)

This reflects the concentration of solutes in the soil water.

As this concentration increases, YO decreases.

In pure water (containing no solutes), YO = 0.

In saline soils, the combination of YO and YM can reduce YSW dramatically, especially as the soil dries (e.g., where YO = -216 kP and YM = -200 kP, YSW = -416 kP, which indicates a major reduction in soil water availability).


Pressure potential y p
Pressure Potential (YP)

This reflects the positive pressure to which water may be subjected in some environments.

In a glass of water, the water at the top of the glass would have a YP of 0; however, the YP of the water at the bottom would have a positive number.

Where a perched water table exists above the base of a soil or sand layer, the YO may be positive as well; however, YO = 0 in most soils.


Textural layers
Textural Layers

Textural layers within the soil profile can seriously disrupt water movement.

Where a fine textured layer occurs above a coarse textured layer, a perched water table can form.

Conversely, where a coarse textured layer occurs above a fine textured layer, a temporary water table can form.


Soil structure
Soil Structure

As a soil becomes more compacted:

  • bulk density increases

  • porosity (especially macroporosity) decreases

  • water movement through the soil is restricted


Water potential gradient
Water Potential Gradient

Water moves from a region of higher YW to a region of lower YW in the soil.

This difference in YW is called the water potential gradient.

As plant roots absorb water, the YW around the roots decreases, creating a water potential gradient.


shade from trees and tower

poor air circulation from trees and shrubs

reduced PAR and inactive phytochrome

allows build-up of temperature and humidity

delicate turfgrass

hot, humid microenvironment

reduced tolerance to environmental stresses

increased disease potential

general deterioration of #4 green

poor soil aeration

O2-deficient rootzone

poor growth, increased compaction

poor internal and surface drainage


Traffic
Traffic

Depending on the nature, intensity, and duration of traffic, affected turfs are susceptible to increased:

  • turfgrass wear

  • soil compaction

  • rutting and soil displacement

  • divots and ball marks


Traffic threshold
Traffic Threshold

The traffic threshold (TT) is the traffic intensity above which a measurable deterioration in turf quality is likely to occur.

Factors that can decrease TT include unfavorable cultural practices and environmental conditions, and poorly adapted turfgrasses.


shade from trees and tower

poor air circulation from trees and shrubs

reduced PAR and inactive phytochrome

allows build-up of temperature and humidity

delicate turfgrass

hot, humid microenvironment

reduced tolerance to environmental stresses

increased disease potential

general deterioration of #4 green

induces severe wear and compaction

poor soil aeration

O2-deficient rootzone

poor growth, increased compaction

concentrated traffic between trap and green

poor internal and surface drainage



Advantages

Solution #1

Disadvantages

Advantages

Problem Statement

Solution #2

Decision

Disadvantages

Advantages

Solution #3

Disadvantages


Shade strategies

Tree Pruning/Removal

Inexpensive alternative

Enables addressing air circulation problem

Ownership concern

Green Relocation

Expensive alternative

Enables addressing other problems (air circulation, drainage, traffic)

Shade Strategies


Air circulation strategies

Tree Pruning/Removal

Inexpensive alternative

Enables addressing shade problem

Ownership concern

Green Relocation

Expensive alternative

Enables addressing other problems (shade, drainage, traffic)

Fan Installation

Works where other (tree removal, green relocation) strategies are not practical

Cost of running power to fan locations

Noise

Installation

Reliability

Air Circulation Strategies


Surface drainage strategies

Green Reconstruction

Expensive alternative

Enables addressing other problems (shade, air circulation, internal drainage, traffic)

Improve Sloping

Inexpensive alternative

Reduces internal drainage problem by lessening hydraulic loading

Surface Drainage Strategies


Internal drainage strategies

Green Reconstruction

Expensive alternative

Enables addressing other problems (shade, air circulation, surface drainage, traffic)

Cultivation/Topdressing

Inexpensive alternative

Increases volume of suitable rootzone

Drill & Fill

Provides water access to more-permeable soil

Internal Drainage Strategies


Traffic strategies

Reduce Traffic Intensity

Increase green size

Increase access to/from green

Move sand bunkers further away from green

Increase TT

Reduce shade

Improve air circulation and drainage

Replace annual bluegrass with creeping bentgrass

Traffic Strategies


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