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