PL SC352 Study Guide - Final Guide: Plastic Mulch, Crop Residue, Mulch
30 Apr 2018
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Cultural Control Methods
A vigorous crop/community is the most effective weed control practice
- good ranch, pasture or community management practices supplements and
can replace other control measures
- practices include
o crop rotation
o time of seeding/early seeding
o increased seeding rates
o decreased row spacing
o choice of competitive crop varieties
o field selection for less competitive crops
o fertilizer placement
o drainage
- also includes
o use of mulches
▪ organic
▪ inorganic
o cover crops
o sequential cropping
Inorganic Mulches
- For high value crops, reduction of crop density (spacing plants out) can increase
value
o but leaves open space for weeds
- Use of plastic mulch blocks weed emergence while increasing available soil
moisture and temperature
- decreases time to maturity
- often done in combination with drip irrigation or trenching
- HOWEVER, plastic gets ripped off and blown around, not environmentally sound.
Organic Mulches
- include straw, compost, wood chips
- blocks weed emergence and success
- reduces moisture loss and soil temperature (more sun reflected)
- can have allelopathy effects (usually viewed as +)
- more environmentally sound BUT:
Mulch + crop residue effects on available N
- C:N ratio is the mass of C compared to the mass of N in the residue (C/N)
- soil microorganisms require about 24:1 to break down residue
- if crop residue is higher, it will extract N from soil to allow breakdown
(immobilization)
- mulch/crop residue can cause short term reductions on available N
o wood chips C/N ratio: 100-500:1, breaks down slowly
- use of wood mulch on reclamation site – N deficient need to supplement N.
Smother crops/green mulch/green manure
Reclamation heavy barley seed, crimp it down, seed it into green mulch
- C:N ratio not the same as straw, more moist
- N advantage legumes in smother crops!!
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
A vigorous crop/community is the most effective weed control practice. Good ranch, pasture or community management practices supplements and can replace other control measures. Practices include: crop rotation time of seeding/early seeding increased seeding rates, decreased row spacing, choice of competitive crop varieties, drainage field selection for less competitive crops fertilizer placement. Also includes: use of mulches, organic inorganic, cover crops, sequential cropping. For high value crops, reduction of crop density (spacing plants out) can increase value: but leaves open space for weeds. Use of plastic mulch blocks weed emergence while increasing available soil moisture and temperature. Often done in combination with drip irrigation or trenching. However, plastic gets ripped off and blown around, not environmentally sound. Can have allelopathy effects (usually viewed as +) More environmentally sound but: reduces moisture loss and soil temperature (more sun reflected) Mulch + crop residue effects on available n.
