1. Off-Road Equipment Management TSM 262: Spring 2016
LECTURE 15: Hay and Forage Harvesting I
Off-Road Equipment Engineering
Dept of Agricultural and Biological Engineering

2. Homework, Lab and Technical Sessions

3. Hay & Forage Harvesting: Objectives
Students should be able to:
Understand the differences between silage and hay making
Identify and explain the processes involved in hay and forage harvesting
Understand what type of equipment can be used for this type of harvesting

4. Hay & Forage Harvesting
Silage - forage converted into livestock feed through fermentation
Cut forage at 70-80% moisture
Allow to field dry to 50-60% moisture
Cut into short lengths for compact storage
Preserve by fermentation in an airtight chamber

5. Haylage
Low-moisture (40-50%) hay silage normally stored in oxygen limiting storage unit
Chopped fine so that it will pack down and exclude air
Hay also converted into livestock feed through fermentation

6. Hay & Forage harvesting
Hay - green forage crop harvested for livestock feed
Stored at low moisture levels (15-23%)
One of least expensive sources of protein
Low bulk density: does not flow readily

7. Forage Classification
Source: Hunt-Farm Power & Machinery Management, p168

8. Functional Processes Chop FORAGE Windrow Wilt Transport Store CUT
Condition
Deflect
HAY
Swath
Wilt
Rake
Dry
Bale
Tran.
Store

9. Terminology - Forage
Deflect – bend crop forward and away from cutter to help align the plant stem horizontally after cut
Cut - cut forage either with a rotary cutter or a sickle bar
Condition - crush, crack or abrade stems so they dry at the same rate as leaves
Windrow - place cut forage in narrow strip for slower drying rate
Wilt - allow to dry in field
Chop - cut into short lengths
Transport - convey forage into wagon for transport to silo and then dump or blow into silo
Store

10. Pull-type Forage Harvesters

11. Pull-type Forage Harvesters

12. Self-Propelled Forage Harvesters

13. Terminology - Hay
Typically completed in two/three passes through the field
Deflect – bend crop forward and away from cutter to help align the plant stem horizontally after cut
Cut - cut hay with a rotary cutter or a sickle bar
Condition - crush, crack or abrade stems so they dry at the same rate as leaves
Swath - spread cut hay over a wider strip than a windrow to accelerate drying
Wilt - allow hay to dry to required moisture level
Rake - turn hay over
Dry - allow hay to continue to dry
Bale - concentrate hay in rectangular or round bales
Transport - transfer bales out of baling unit to wagon or leave on field
Store

14. Hay Equipment-Cut and Condition
Pull-type mower-conditioner
Two cutting modes
Sickle bar (reciprocating)
Disc (rotary)

15. Hay Equipment-Cut and Condition
Self-propelled mower-conditioner
Cutting heads
Sickle bar (reciprocating)
Disc (rotary)

16. Hay Equipment – Rake

17. Hay Equipment - Balers

18. Functional Processes Chop FORAGE Windrow Wilt Transport Store Cut
Condition
HAY
Swath
Wilt
Rake
Dry
Bale
Tran.
Store

19. Cutting Mechanisms Sickle bar/cutting with countershear
Knife sections and ledger plate replaceable
Knife edges smooth or serrated
Cutterbar floats over ground

20. Cutting Mechanisms (cont.)
Cutterbar and associated reel mounted on separate framework connected to machine by spring-loaded four-bar linkage
Reel

21. Cutterbar should have proper tilt, register, and alignment
tilt = rotate cutterbar to raise or lower guard points
register = cutterbar symmetry to guard spacing
alignment = cutterbar p/2 to travel direction

22. Sickle mechanism Convert rotary motion into reciprocating motion
Slider-crank
Spatial-crank
Commonly used, compact size and easy to integrate to drive train

23. Pickup Reels
Purpose - push crop over cutterbar for cleaner and more efficient cutting
In down or tangled crops, reel can lift forage before cutting
Used on mower-conditioners, forage harvesters and combines

24. Pickup Reel Mechanisms
Three main types of control for reel teeth
Concentric spider control
Planetary gear control
Cam control

25. Pickup Reel with Cam Control

26. Impact cutting (horizontal axis)
Lacerating effect of knives provides conditioning
Upright crops-flail mower recovers 5-10% less of crop than sickle bar mower
Flail mower good at recovering severely lodged crop

27. Impact cutting (vertical axis)
Drum type - drive above cutting blades
Disk type - drive below cutting blades
Blades can be counter-rotating or rotating in same direction
Blades designed to overlap
Blade tip follows cycloidal path over ground

28. Functional Processes Chop FORAGE Windrow Wilt Transport Store Cut
Condition
HAY
Swath
Wilt
Rake
Dry
Bale
Tran.
Store

29. Conditioning Cross-section of alfalfa stem Roll Conditioning
Conditioned
Flail Conditioning
Unconditioned