Mulching and other methods of weed control (3).ppt

MULCHING

1. Mulching & Other
Methods for Weed Control
Prepared by:
L. Robert Barber, Frank Cruz, & Ilene Iriarte
For:
Guam Cooperative Extension Service & Guam Department of
Agriculture
Funding provided by:
United States Department of Agriculture Natural Resources
Conservation Service, Western Region Sustainable Agriculture
Research and Education, Administration for Native Americans,, &
Sanctuary Incorporated

2. What is a weed?
•Plant growing out of place
•A plant can be desirable in one situation
and be a pest in another
–Can be fast growing
–Often produces a lot of seeds or has persistent
roots

3. How Weeds Harm Desirable Plants
•Competes for water, nutrients, light, and
space
•Harbors pests and diseases
•Can release toxins into the soil

4. Weed Management
•The best time to begin an effective weed
management program is before planting
•Proper site preparation can reduce weed
problems
•Monitor frequently for weeds
•Remove weeds while they’re seedlings
•Maintain a directed low volume irrigation
system
•Minimize disturbances in the soil
•Correctly maintain mulch

5. Weed Control Practices
•Mechanical
–Hoeing/Hand weeding
–Plowing, harrowing, cultivating, other tillage
•Fire/Propane Burner
•Mowing/Bush cutting
•Ground Cover –Living Mulches
•Chicken Tractor
•Mulching

6. Mechanical Weeding -Cultivation
•Labor, equipment and energy intensive
•Bare soil more susceptible to erosion
•Frequent tillage speeds organic matter
decomposition.
•Brings buried seeds to the surface
–Cultivate once germinated
•Plant spacing must allow for equipment

7. Fire
•Fire can be used to remove weeds in a big
area
–Burns the organic matter
–Leaves soil bear and high chance of erosion
•Propane Burner is used for spot
treatments
–Must be careful

8. Mowing & Bush cutting
•Benefits of maintaining a living cover and
mowing or bush cutting
–May reduce competition
–Can help prevent soil erosion
•Disadvantages:
–Often damages desired plants
–Physically harms plants –Bush cutter disease
(careless cuts girdle tree) kills huge numbers
of trees on Guam.

9. Ground Covers or Living Mulches
•Can be natural cover developed by frequent
mowing, or can be planned planting like sweet
potato or perennial peanut or other cover crop.
•Benefits
–Prevents germination of weed seeds
–Prevents soil erosion
–Insulates soil
–May add nitrogen to soil (ex. Perennial peanut)
–Attractive
•Disadvantages
–Can provide a habitat for pests
–Can compete for water & nutrients

10. Chicken Tractor
•Mobile Pens
•Weeding
•Pest Control
•Fertilizer
•Food

11. Types of Mulch
•Two types of mulch; Organic & Inorganic
•Inorganic Mulch (Plastic sheets):
–Does not decompose
–Non-living
–May prevent water loss, soil protection,
increase absorption
–Does not improve soil or add nutrients
–Good for walk ways, and paths

12. Benefits of Mulch
•Conserves water & reduces erosion
•Improves soil structure, & absorption
•Adds nutrients
•Suppress weed growth
•Prevents pathogens from splashing on foliage
•Insulates soil
•Increases microorganisms, earthworms, & insects
•Prevents trunk damage from bush cutter
–Limits weeds near plant so no need to cut close to plant
•Reduces landscape maintenance

13. Organic Mulch
•Organic Mulch:
–Living Materials
–Categorized by size; Fine or Coarse Material
–Fine Material:
•A lot of surface area
•Can suffocate plants
–Coarse Material:
•Doesn’t blow away as easily
•Water & air can penetrate through

14. Organic Mulch
•Examples of Organic Mulch:
–Grass clippings, small leaves*
–Wood chips**
–Pine needles (Gago Tree)**
–Banana leaves & Palm fronds**
–Coconut husks**
–Branches**
–Compost
–Shredded paper*
*Fine Material & ** Coarse Material

15. What is in a Mulch
•Decaying organic material
•Undecomposed compost
•Applied to surface of the soil over time blends
with the soil
•Consists of:
–Nutrients
–Leaves
–Branches
–Microorganisms
–Insects

16. Palm fronds around breadfruit tree

17. Now That You Have Mulch
•Apply in planting beds
•Around established trees, & newly
planted trees
•Mulch will eventually need replacing
•Fine material need to be replaced often
•Coarse material can be replaced either
once a year to every two years

18. Mulched Raised Bed
Bed mulched with pine
needles (Gago tree)

19. How To Apply Mulch
•Leave a 3-6” gap from the base of the plant
to mulch
•For individual trees:
–Make a circle that is 2’ in diameter for every
inch of trunk diameter
–Increase size as tree gets bigger
•For planting beds:
–Mulch entire bed

20. Undesirable -Mulch up Against Trunk

21. How Much to Apply
•Thickness depends on types of material
•Fine Material:
–No thicker than 2 –3 inches
–Can mat together & suffocate plants
•Coarse Material:
–At least 4 inches
–Thinner weeds can penetrate through if too
thin a layer.

22. Possible Problems
•Mulch can turn “sour”
–Air was not allowed to penetrate through
–Toxic substances are produced
–Plants drop leaves, turn yellow, and can die
–Smells like sulfur, vinegar, or ammonia

23. Wire Chicken Barrier

24. Possible Problems
•Chickens and Pigs love it too
–Can destroy plants, dig up roots
–Scatter mulch
–Where animals are a pest, create a barrier