Check test

1
Check test

• Seeding rate Seed released in 100 x 43560
• 100 x drill width
• Run drill until seed are dropping
• Cover seed drop holes with sack
• Run drill over 100 feet (this is good time to
  make sure all seed holes are working)
• Weigh the amount of seed dropped

2
Seeding example

• Seeding rate Seed released in 100 x 43560
• 100 x drill width
• Seeding rate 0.5 lb x 43560
  
• 100 x 12
• Seeding rate 21780
  18.15
• 1200
• This example answer 18.15 lbs of seed per acre

3
Forage Physiology and Forage Ecology (Chapters
13-14)

• Forage Crops 4310

4
Physiology

• Processes and activities associated with the
  functioning of living organisms
• Understanding these basic concepts assures
  appreciation for the complex world of forages
• Helps explain differences between annuals and
  perennials warm seasons and cool seasons
  legumes and grasses

5
Light - Photosynthesis

• Photosynthesis is the conversion of light energy
  into chemical energy by living organisms. The raw
  materials are carbon dioxide and water, the
  energy source is sunlight, and the end-products
  include glucose and oxygen.
• - Wikapedia

6
Photosynthesis

• Low efficiency
• 3 of cool season grasses
• 5 6 for warm season grasses
• C3 Plants Fix energy in 3 carbon units -Cool
  season, less efficient - Tall fescue, ryegrass
  and all legumes
• C4 Plants 4 carbon units Warm season, more
  efficient
• bermuda, pearl millet and corn

7
C4 Plants are more efficient than C3 Plants
because

• C4 plants can utilize near full sunlight while C3
  plants become light-saturated at 25 50
  sunlight
• C3 Plants have photo-respiration an older and
  less efficient photosynthetic mechanism but
  C3s need less energy input, so do better in cool
  weather

8
Photosynthesis

• Occurs in structures in plant leaves, called
  chloroplasts
• Chlorophyll pigment is required
• Temperature, water and light affect photosynthesis

9
Individual Leaf photosynthesis

• Slows Photosynthesis
• Nitrogen deficiency
• Water stress
• Shade (very important!)
• Old leaves are slow photosynthesizers

• Spurs photosynthesis
• Good fertility
• Irrigation
• Sunlight
• Young leaves

10
Light relationships in pasture

• Related to total photosynthesis of stand
• Growth results in stand shading itself
• As sward increases, efficiency decreases, mostly
  due to shading
• Point harvest before shading wrecks efficiency

11
Effects of shading

• Shading reduces photosynthesis so plants figure
  ways to reduce this effect
• Branching, leaf length and width affected by
  shading
• Tall growing legumes like alfalfa allow more
  light into canopy can be harvested less
  frequently
• Warm season grasses like corn, sorghum-sudan, and
  pearl millet (C4s) grow tall and have leaf angle
  that makes high yield over fairly short growing
  season

12
Light (continued)-Practical Implications

• Forage removal needs to be frequent enough to
  prevent leaf loss from shading.
• In general, enough leaf needs to be taken (grazed
  or cut) to prevent shading but enough should be
  left for photosynthesis to assure efficient
  regrowth
• Take more with C4 plants (bermudagrass) and less
  with C3s (fescue)

13
Temperature

• Optimum growth ranges
• Cool season grasses 60 to 80 degrees
• Warm season grasses 85 to 95 degrees
• Clovers 65 to 75 degrees
• Alfalfa 78 degrees

14
Temperature effects on root growth

• Roots often grow at cooler temperatures than
  leaves.
• As temp falls, leaf growth slows and root growth
  may increase
• Opt. root growth temperatures about 10 degrees
  lower than opt leaf growth temps.
• Allows root growth in early spring, but may
  inhibit some leaf development

15
Fescue and bermudagrass together

• Often found in the same pasture / hay field
• The further north the more likely fescue
  dominates
• Warm, dry weather favors bermudagrass
• Wet weather favors fescue
• N-fertilizer in Fall and late winter favors
  fescue
• May July N-fertilizer favors bermuda

16
Water

• Needed for photosynthesis, but less than 1 of
  water uptake goes for this
• Most is transpired or lost by diffusion through
  leaf stomata (pores)
• Water cools the plant and transports nutrients
• C4 species more water efficient than C3s
  (bermuda does better without water than fescue)

17
Drought effects

• Leaf and tiller growth slows stops
• Some minerals, like K, accumulate
• Nitrate accumulates
• Root growth may be stimulated, at least
  temporarily
• Leaf rolling in grass species and leaf folding in
  legumes

18
Deeper rooted plants are more drought tolerant

• Bermudagrass 78 inch root depth
• Bahiagrass 61 inches
• Fescue - 48 inches
• Orchardgrass 38 inches

19
Flood / poor drainage tolerant species

• Reed canarygrass
• Johnsongrass
• Dallisgrass
• Annual ryegrass
• Fescue
• Bahiagrass

20
Carbohydrate Reserves

• Roots Alfalfa, red clover, Sericea
• Rhizomes bermudagrass, johnsongrass,
  switchgrass
• Stolons white clover
• Stem bases Fescue, dallisgrass, orchardgrass

21
Carb. Reserves are Important

• This energy is needed to recover after stress,
  such as drought, or after extended dormancy, such
  as in spring following a long, hard winter

22
Understanding Carb storage affects management

• Johnsongrass and switchgrass grow tall with lots
  of energy in leaves continuous close grazing
  depletes reserves
• Bermudagrass puts a lot of energy in rhizomes and
  low running vegetation, so can take low cutting,
  and close grazing

23
Seed Physiology

• Three essential components Embryo, store of
  energy, protective seed coat
• Can withstand drying lt 10 moisture

24
Seed physiology

• Seed storage affects germination
• Each 1 reduction is seed moisture doubles seed
  longevity
• Each 9 reduction in seed storage temp. doubles
  seed longevity
• Point store seeds in cool, dry location

25
Seeds are tough and can live for some period of
years

• Short life (1 to 3 years in storage) bermuda,
  dallisgrass, orchardgrass
• Medium (3 to 5 years) Fescue, bahiagrass,
  Timothy, Sericea, Crimson, red clover
• Long life (hard seeded 5 to 10 years) Alfalfa,
  Arrowleaf, and white clover

26
Forage Ecology 4 components

• Non-living components water, soil, aire and
  sunlight
• Plants that capture solar energy
• Herbivore consumers cattle, sheep goats,
  horses, wildlife, insects and carnivores that eat
  the herbivores
• Decomposers fungi, bacteria, earthworms

27
The Pasture Environment

• Atmosphere temp and rainfall
• Site Elevation, soil type, drainage, slope and
  exposure

28
Consumer Organisms in the Pasture Environment (p.
129)

• Consumer organisms Cattle, horses, deer, sheep,
  goats, insects, nemotodes
• Carnivores
• Grazing animals have profound effects on the
  pasture environment. Effects include
• Timing and intensity of defoliation
• Treading
• Excretion of feces and urine

29
Defoliation

• Most important influence on pasture environment
• Characteristics of plants affect consumption
  thorns, spikes, alkaloids, tannins
• Young, growing plants are generally more
  appealing to grazing livestock
• Fescue stands defoliation Johnsongrass does not
  like continuous defoliation, therefore disappears
  under close grazing

30
Broomsedge

• Native grass
• Old saying Broomsedge is a sign of lime
  deficiency
• Cattle will consume at early stage of growth, but
  it rapidly matures into a very undesirable forage
• Good management favors other species (fescue,
  bermuda)
• Good fertilization and managed grazing will
  supress broomsedge, making it disappear

31
Treading

• Good on seeds
• Terrible on crops
• Horses are worst

32
Excretion

• Grazing animals consume forage and deposit
  nutrients in concentrated areas of feces and
  urine
• Concentrates N, P and K, but esp. P
• Grazers dont typically graze near their own
  deposits
• Why?

33
Spreading seed

• Some seeds cling to hair and are transported
• Some are transported by being eaten then excreted
  (sericea, clover, even fescue)

34
Decomposers

• Goal is more organic matter
• Fungi
• Bacteria (lower picture is close-up of
  bacteria-rich legume nodule. Reddish color is
  from leghaemoglobin)
• Earthworms turn over up to 25 of soil per year

35
Challenges

• Persistence of Eco-friendly forages perennials
  like fungus-infected fescue, bermuda and the
  annual, crabgrass, dominate. Can we get more
  legumes to persist? Sericea?
• Wasted pasture and hay?
• Nutrient recyclying