This document discusses land preparation and tillage practices. It covers the aims of land preparation such as loosening soil, improving aeration and water infiltration. It describes different tillage operations including primary tillage using implements like moldboard plows and disc plows, and secondary tillage using cultivators and harrows. Conservation tillage systems are introduced, including no-tillage, mulch tillage, and ridge tillage. The advantages and disadvantages of animal, human, and machine power for tillage are presented. The document stresses that tillage can impact soil fertility positively or negatively, and should aim for minimum soil disturbance.

1. Land Preparation
Crop Science 2
Alminda M. Fernandez, Ph.D.
University of Southeastern Philippines
Tagum – Mabini Campus

2. Land preparation
• is a combination of tillage practices that
places the soil in the best physical condition
for plant establishment and crop growth.
• covers a range of soil disturbances from zero-
tillage, which minimizes soil disturbance
through to a totally ‘puddled’ soil, which
actually destroys soil structure.

3. Aims of Land preparation
• Loosen the soil to facilitate the penetration of
plant roots
• Improve aeration (N, O)
• Increase infiltration of water
• Reduce evaporation
• Destroy or control weeds and soil pests
• Incorporate crop residues and manures into
the soil

4. Aims of Land preparation
• Prepare the site for seeds and seedlings
• Repair soil compaction caused by previous
activities
• Decrease ped or clod size
• Reduce wind and water erosion by leaving a
rough surface
• Stimulate microbial activity

5. What is the appropriate tillage system,
pattern and equipment for your field?
Dry and level field Wet and level field

6. Dry tillage – manual, animal, mechanical?

7. Wet tillage – manual, animal, mechanical?

8. Types of Tillage Operations
• Primary tillage
• Secondary tillage
• Seedbed preparation
• Inter tillage

9. Primary tillage
• the most aggressive tillage operation
• undertaken when the soil is wet enough to allow
the field to be ploughed and strong enough to
give reasonable levels of traction
• after the crop harvest or at the beginning of the
next wet season
• includes the ploughing operation which is
opening of the compacted soil with the help of
different ploughs

10. Ploughing

11. objectives of primary tillage
• Open the hard soil
• Separate the top soil from lower layers
• Invert the soil whenever necessary
• Till the soil to attain a reasonable depth (10-
15cm ) with varying clod sizes
• Kill weeds by burying or cutting and exposing
the roots
• Soil aeration and water accumulation
• Chop and incorporate crop residues

12. Primary Tillage Implements
• Moldboard plough
• one-way disc plough
• Tine disc plough
• Offset disc plough

13. Moldboard plough
• causes total inversion of the
soil sod and relies on the
digging point for penetration
• throws the soil in one
direction
• least damage to soil structure
• works well in very hard soil
conditions but no built stump
or obstacle protection

14. One-way disc used
with 4-wheel tractor
• causes total inversion of the soil sod and relies
on the ploughs in built weight for penetration
• throws the soil in one direction
• works well in hard soil and heavy trash
conditions and can ride over stumps or
obstacle in the soil
• Power requirement is less than a moldboard

15. Offset disc for 4-wheel
tractor
• capable of operating offset
from the tractor
• throws the soil in different
direction
• very versatile and can be
operated in any ploughing
pattern
• widely used in upland situations

16. Tine plough
• most versatile
• used in secondary tillage
• modified to be used as a seed drill
• dry working situations
• cut the soil rather than invert the soil
• kill weeds by cutting and lifting the weeds to
the surface
• lower power requirements

17. Secondary Tillage
• any working completed
after primary tillage
• shallower and less
aggressive
• includes the operations
performed after ploughing
such as leveling, discing,
harrowing etc.

18. Secondary Tillage Implements
• peg tooth harrow
• disc harrow
• tined cultivator
• rotary tiller
• inter row cultivator

19. Peg tooth harrow
• used in animal and 2-
wheel tractor powered
systems
• for second workings,
soil puddling and land
leveling

20. Disc cultivator
• used in dry fields and
upland situations
• very aggressive action
of the plough gives
good weed control and
cuts and buries crop
residues

21. Tined cultivator
• used for secondary tillage
and as a seed drill
• dry working situations
• cut the soil rather than
invert the soil
• kill weeds by cutting and
lifting the weeds to the
surface

22. Rotovator
• for secondary workings
and especially seedbed
preparation
• Upland and flooded fields
• very aggressive action,
which pulverizes the soil
and buries weeds and
crop residues

23. Upland Tillage
• aerobic soil conditions
• non-puddled soils
• no freestanding water in the fields
• too dry soils will not till easily, in clay soils large
clods may be formed
• very wet, near soil saturation, smearing and
soil sealing can become problems
• water erosion can be a problem and ploughing
on the contour is recommended

24. Seedbed Preparation
• for germination of seeds
& growth of crops, called as SEEDBED
• includes harrowing, leveling, compacting the
soil, preparing irrigation layouts such as
basins, borders, rides & furrows etc.
• carried out by using hand tools or implements
like harrow, rollers plank, rider etc.

25. Inter tillage
• carried out in the standing crop
• after sowing or planting and prior to the
harvesting of crop plants
• includes gap filling , thinning , weeding ,
mulching, top dressing of fertilizers, hoeing,
earthling up etc.

26. Tillage Patterns
• reduces the time spent in non-productive
work
• minimize the number of turns and maximize
the length of the tillage runs
• circuitous, up and back or headland and
working in lands

27. Circuitous pattern
• used with moldboards,
discs and offset discs
• most animals are
accustomed to working
• ends up with a large cut
out furrow in the center –
difficult to drain and get an
even depth of cultivation

28. Up and back or headland pattern
• runs parallel to each other
• used for tined implements,
rotovators, harrows and
reversible ploughs
• most field efficient system
and if equipment is correctly
set up and operated should
not leave furrows in the field.

29. Land system
• ploughing to begin in the
center of the field and
works out to the edges
• Requires measurement of
the field to establish the
center point
• used with all types of
ploughs

30. The use of animals
The advantages of using animals include:
• cheap to maintain
• multi-purpose use for meat and milk,
• self-replacement and
• manure production

31. The use of animals
Disadvantage of using animals include:
• have limited daily working hours
• need feeding
• need protection against pests and disease.
• slow
• high person to power ratio
• limited range of working conditions
• require training

32. The use of human power
Tasks undertaken include:
• land preparation including ploughing, soil
leveling and constructing levees and drains
• plant establishment
• pest control
• crop harvesting and transporting
• grain processing

33. Human Power

34. The use of Machines
The advantages
• multi-purpose vehicle
• operate in harder
conditions than animals
or humans
• operate in both wet and
dry conditions
• fairly simple mechanical
design
The disadvantages
• cost of owning
and operating
• operator fatigue,
although ride-on
versions are now
available.

35. Use of Machines

36. CONSERVATION VERSUS CONVENTIONAL TILLAGE
Conventional tillage:
• Mechanized
systems
• Traditional tillage
Conservation tillage:
• no-tillage (slot planting),
• mulch tillage,
• strip or zonal tillage,
• ridge till (including no-till
on ridges)
• reduced or minimum
tillage.

37. Conventional tillage system
Mechanized system
• mechanical soil
manipulation of an
entire field,
• by ploughing
followed by one or
more harrowings
Traditional tillage
• manual labour, using
native tools (cutlass
and hoe )
• clearing is non-
exhaustive, leaving
cover on the soil and
the root system

38. No tillage
• one-pass planting and fertilizer operation
• soil and the surface residues are minimally
disturbed (Parr et al. 1990)
• eliminate all preplanting mechanical seedbed
preparation
• only opening of a narrow (2-3 cm wide) strip or
small hole in the ground for seed placement to
ensure adequate seed/soil contact

39. No tillage
• Weed control thru herbicides and crop
rotation
• soil surface is covered by crop residue mulch
or killed sod
• appropriate for Luvisols in the humid tropics
• Wheat, coffee, others in some parts of USA
• Slow adoption

40. No tillage
Advantage
• more effective control
of soil erosion
• increased water
storage
• lower energy costs per
unit of production
• higher grain yields
Disadvantage
• chemical fallow
• heavy use of
herbicides for weed
control

41. Mulch tillage
• causing least soil disturbance
• leaving the maximum of crop residue on the
soil surface
• obtaining a quick germination, adequate stand
and a satisfactory yield (Lal 1975, 1986)
• chisel plough can be used in the previously
shredded crop residue to break open any hard
crust or hard pan in the soil
• Coffee, banana, wheat, barley in USA

42. Strip or zonal tillage
• seedbed is divided into a seedling zone and a
soil management zone (Lal, 1973, 1983)
• the seedling zone (5 to 10 cm wide) is
mechanically tilled to optimize the soil for
germination and seedling establishment
• interrow zone is left undisturbed and
protected by mulch
• also achieved by chiselling in the row zone to
assist water infiltration and root proliferation.

43. Ridge till
• soil is left undisturbed prior to planting
• one-third of the soil surface is tilled at planting
with sweeps or row cleaners
• planting of row crops is done on preformed
cultivated ridges
• weeds are controlled by herbicides
• maize and soybean production in the USA
(Parr et al. 1990)

44. Reduced or minimum tillage
• tillage and cultivation systems not covered
above but meets the 30% residue requirement
(Laryea et al. 1991)
• Africa

45. Till or not to Till?
Tillage
• Improves aeration
• Incorporates crop
residues
• Facilitates root
penetration
• Suppresses weeds
Zero-tillage
• Improves soil
structure
• Maintains soil organic
matter
• Supports soil
organism
• Prevents soil erosion

46. Lesson to be learnt
• Soil cultivation can have positive or negative
impact on soil fertility
• Frequent tillage can lead to decrease of soil
organic matter, nutrient losses, and soil
erosion
• Soil cultivation should aim on a minimum
disturbance on soil life…….

48. How to control Soil Erosion?
1. COVER methods
– Mulching
– Green manure
– Mixed cropping and intercropping
– Early planting
– Crop residues
– Agroforestry
– Minimum cultivation

49. How to control Soil Erosion?
2. BARRIER methods
– Man-made terraces
– Contour ploughing
– Contour barriers
– Natural terraces
– Medias lunas

50. Medias lunas
• This is a helpful system for reclaiming badly
eroded land which has been used successfully
in Bolivia.
• Medias lunas or crescent shaped depressions
are built on sloping land.
• The crescent shapes are built at the end of the
rainy season so the ridges made can be
compacted well.

51. Medias lunas
• The crescent collects the rainwater and soil.
• Trees - usually legumes - are planted when the
next rainy season begins and protected by
thorn branches from grazing animals.
• After 3 or 4 years each media luna will be
covered with vegetation.
• Later, as the soil continues to improve, crops
may be grown in the medias lunas.