chapter 15 tillage: working the soil to provide a good environment for seed placement, germination,...
TRANSCRIPT
Chapter 15
• Tillage: working the soil to provide a good environment for seed placement, germination, and crop growth
3 goals for Tillage
• 1. Weed Control
–Before Planting
•Kill weeds
•weakens perennials–After Planting
•destroys weeds
•covers seedlings
2. Alteration of Physical Soil Conditions
• Structure, Moisture, and Temperature
–Stirs and loosens soil
– improves aeration
–creates suitable medium for growth
–may breakup soil compaction
2. Alteration of Physical Soil Conditions
• Causes long term decline in Structure
– loss of organic matter
–crushes soil aggregates• Moisture and Temperature
– tilled warms earlier, causes earlier seeding and better germination
Crop Residue Management
• amount depends on crop
–8500 lbs/acre off of 150 bu corn
–5600lbs/acre off of 100 bu corn
Crop Residue Management
• amount depends on type of tillage
–Plowing 5%
–Field Cultivator 80%
–Chisel 80%
–Disc 6” 25%, 3” 50%
–Harrow 65%
Seedbed Preparation
• Culmination of all 3 aspects
• Meets requirements for seed to grow
–moisture, temperature
–aerated, yet compacted
– free of clods• Type of seed determines how smooth you
need seedbed
Conventional Tillage
• Primary Tillage
–Breaks up soil and buries crop residue– inverting equipment
•Plowing, time consuming, no residue•Discing
Conventional Tillage
• Secondary Tillage
–Produces fine seedbed that breaks up into smaller chunks
–mixing implements
Conservation Tillage
• Leaves 30% of residue
–reduces erosion by 40-50%
–reduced tillage
– fewer trips, compaction less
Conservation Tillage
• Mulch Till
–Chisel, Secondary, 30-50% residue• Strip Till
–No Primary tillage
–planter tills band of soil and plants
–bares 1/3 of soil
–50% residue
Conservation Tillage
• Ridge Till
–plants cleaned strip
– seed planted on ridge
–2/3 residue
Conservation Tillage
• No Till
– specialized planters
–90% untouched ground
–Herbicides used to control weeds rather than tillage
Differences between Conservation and
Conventional
• Yields
– slightly lower in Conservation• Equipment
–conservation needs specialized, but fewer• Fertility
–Conservation remains moist longer,
–N needs to be deeper incorporated in Conservation
–PH may be higher
Drawbacks to Conservation
• Management
• Adapted for select soils
• Perennials can be a problem
• Compaction in No Till can be a problem
• PH lowers
• Use of herbicides
Cropping Systems
• 3 Different ways to decide what to plant
Plant the Market
• Plant what the market wants you to, highest price
Suit to Operation
• Plant what you will use in ag operation
Crop Rotation
• 1.Continuous Cropping
–grows same crop every year
–yields decline after several years
Crop Rotation
• Disadvantages
– planting less profitable crops
– do not use crops that you need to plant
Crop Rotation
• Advantages
–Control disease and insects
–Control weeds
• allelopathy: chemical emitted by a crop that kills weeds in next crop
– supplies N
– Improves O.M.
–Reduces erosion
Dryland Farming
• No irrigation
• Summer Fallow
– left fallow for 1 crop season
– control weeds and crop on field
– 25% of rain will be stored in ground
Dryland Farming
• 3 Problems
• 1. Wind erosion
• 2. Decline in O.M.
• 3. Saline Seeps
Dryland Farming
• Saline Seeps:
–Deep rock layer stops water and pushes it downhill
–water carries salt with it
– comes out at low spots of hill
–water evaporates leaving salt behind
Dryland Farming
• Avoid saline seeps by moving the water before it can evaporate
Rangeland
• Four SCS ranks
– 1. Excellent
– 2. Good
– 3. Fair
– 4. Poor
Rangeland
• Things to do to make rangeland more productive
• 1. Control grazing
• 2. Fertilize
• 3. Seed out new plants
Organic Farming
• No inorganic fertilizers or synthetic pesticides are used
• Usually use rotation w/legumes to supply N
• Rely on tillage and cultivation
– rotary hoe
Organic Farming
• Results of O.F.
– better bean and oats yield
– erosion is reduced
– use 1/3 of energy
– sell to regular markets
– some utilize only part organic
LISA
• Low Input Sustainable Agriculture
–Maximizes profits by reducing costs
–Minimizes off farm inputs