Cymraeg

Crop Production
Session 3 - Preparing and Cultivating Land for Planting

This resource is suitable to support Level 2 Agriculture courses.

Content

This unit on preparing and cultivating land for planting will contain information on the following:

  • Session 1 - Cultivation equipment
  • Session 2 - Land preparation for different crops
    • red tractor with cultivation equipment on front

    Section 1 - Cultivation Equipment

    Preparing and Cultivating Land for Planting

    Cultivation equipment

    Soils need to be in a condition suitable for establishing a crop. The main objectives of soil cultivation are:

  • Burying trash (previous crop remains).
  • Reducing compaction.
  • Producing a suitable seedbed.
  • Shaping the soil for the next crop (e.g. furrowing for potatoes).
  • Improving harvesting conditions.
    • image of cultivation equipment shaping the soil

    Primary and Secondary Cultivation

    The cultivation process is split into the primary and secondary cultivation.

  • Primary cultivations break up the soil while secondary cultivations refine the topsoil to produce the required soil particle size, firmness and surface shape for seed germination and plant growth.
  • Particular equipment is used for particular cultivation.
    • image of equipment breaking up soil

    Subsoiler

    Why is there a need to subsoil?

  • Repetitive passes of tractors and equipment can increase soil density beyond the topsoil layer. Cultivation ‘pans’, which are dense soil layers can also be created by the smearing of soil by wheels or tines. Both of these occurrences result in poor drainage and root penetration.
    • subsoiler

    Subsoiler

    A subsoiler is used to loosen the soil that is deeper than can be reached by routine cultivations. The subsoiler consists of one or more tines, reaching to a depth of up to 60cm, the foot of the subsoiler is fitted with horizontal wings, loosening the soil beneath the ploughing depth.

  • A pair of shallow leading tines, placed either side of the main tine is designed to loosen the upper soil layer.
  • Subsoiling is a slow process and requires a high power input.
    • subsoiler

    The Plough

    Ploughing is the first process in seedbed preparation in most cases. It’s an excellent method of:

  • Separating soil particles.
  • Disintegrating large colds.
  • Inverting the topsoil to bury weeds, crop remains and potential diseases.
  • Setting up the soil for frost penetration.
    • plough

    Mouldboard Plough

    The most common implement used to plough is the mouldboard plough. The general components and function are:

  • ‘Disk coulter’ to vertically cut into the ground.
  • Forward-raked point to aid penetration into the ground.
  • ‘Mouldboards’ which turn over the furrows.
  • ‘Tailpiece’ to help position the furrow.
  • Vertical plate ‘landside’ to resist the horizontal thrust of the turning furrow.
    • mouldboard plough

    Types of Mouldboard Ploughs

    There are two main types of mouldboard ploughs:

  • The conventional or ‘one way’ plough.
  • The reversible plough.

    • The main difference is that the reversible plough carries two sets of mouldboards unlike the conventional plough that carries one set, one set of mouldboards on the reversible turns the soil to the left and the other set to the right, when one side of the field has been reached the plough can be rotated 180º and the other set of mouldboards used so that there is no need to travel back to the original position of the field to begin a new run.

    Single Plough / Reversible Plough

    plough
    plough

    Reversible Plough

    The advantages of the reversible plough are:

  • Less field marking needed.
  • Avoids excessive headland travel which adds to soil compaction.
  • Less time consuming.
  • Lower fuel consumption.
    • reversible plough

    Mouldboard Plough Characteristics

    Mouldboards can produce a range of effects on the soil depending on their length and degree of curvature, the effect produced by different boards can be modified by operating at different speeds.

  • Standard furrow width is 35cm and there can be as many as 12 mouldboard on one plough. It’s possible to vary the ploughing depth of a plough, this is advisable to avoid creating pans when ploughing year after year at the same depth.
    • closeup of mouldboard plough

    Deep Ploughing

    Deep ploughing is needed for some crops e.g. root crops and potatoes but care should be taken that poorly weathered subsoil isn’t bought up.

  • Ploughing depth should not exceed two third of the width of the furrow otherwise the furrow slice will not turn satisfactory.
    • image of soil after deep ploughing

    Cultivators

    There are different types of cultivators, tined cultivators are simply dragged behind the tractor while more complex rotary cultivators are driven by the tractors’ ‘power take off’ (PTO) shaft.

  • Cultivators can be used as primary or secondary cultivators depending on the tilth required and the soil type and condition.
    • image of cultivator being attached

    Tine Cultivator

    This is a tined implement predominantly used on ploughed ground to loosen and break up soil clods up to ploughing depth. They can be fitted with either rigid or spring tines.

  • Rigid tined cultivators can be used as primary cultivators instead of ploughing, two passes of the field at different angles are needed to obtain sufficient soil disturbance.
    • stock image of tine cultivator

    Spring Tined Cultivators

    Spring tines that are used on ploughed ground vibrate as the machine moves forward effectively shattering clods.

  • Trash and stronger clods are bought to the surface, crumbler rollers or light harrows are available as extras to fit on the rear to produce a level finish.
    • spring tined cultivator

    Rotary Cultivator (Rotavator)

    This is a horizontal rotor carrying either L shaped blades or spikes with power applied to it via the tractor’s PTO shaft, they rotate to produce either a coarse or fine tilth depending on the tractor’s speed or engine revolutions.

  • A working depth of 20cm is controlled by a land wheel or rear crumbler roller.
    • rotavator

    Harrows

    There are many types of harrow but the main objective of all is to break down the soil to create an effective seedbed.

    harrows on field

    Disk Harrow

    This type of harrow consists two or four adjustable axles, each having a number of saucer-shaped discs, between 30 and 60cm in diameter mounted along its length. The action of the harrow on the soil depends on the angle of the axle.

  • When set at right angle to direction of travel discs cut into the soil and break down the clods with a minimal degree of soil throw and mixing. Increasing axle angle results in greater degree of soil loosening and mixing.

    • Disk Harrow

    Disc harrows are widely used as secondary cultivators to prepare many types of seedbeds but can be used as a primary cultivator on old grassland before ploughing to allow the plough to bury the turf better or to initiate the breakdown of straw stubble by mixing it with soil.

    disk harrow

    Tine Harrows

    This consists of small vertical tines or spikes carried on a rigid or flexible (chain) frame, often dragged over cultivated land to finish breaking up the soil into fine tilth. It can also be used after drilling to ensure that the seeds are covered or the chain harrow can be used on grassland to remove dead, matted grass or spread cow pats after grazing.

    tine harrows

    Tine Harrow and Seed Drill Combination

    Tine harrows are often pulled behind other machines e.g. cultivator or seed drills to achieve two operations at once.

    Power Harrow

    As with the rotovator, the power harrow is driven by the PTO shaft of the tractor. It consists of pairs of spiked tines rotating on vertical axes with neighbouring sets of tines contra-rotating at high speeds to produce a shattering effect.

  • This causes a lot of soil movement in one pass. The action of the tines also levels and compacts the seedbed without raking up buried trash or subsoil.
    • closeup of power harrow

    Power Harrow Seed Drill Combination

    They are most valuable on heavy soil when preparing fine seedbeds for crops such as potatoes and sugarbeet.

  • Seed drills are often used in conjunction with the power harrow to combine the operations of seedbed preparation and drilling.

    • Rollers

    These range from the flat roller to crumbler roller and the Cambridge roller.

  • The effect of the roller depends on its weight, soil contact area, roller diameter and forward speed.
    • image of rollers on field

    Flat Roller

    Light flat rollers are used to consolidate the top few centimetres of the soil so that plant seeds can contact with soil particles and so that the soil can hold more moisture.

  • Heavier flat rollers are used to crush clods and break surface crusts. Rollers should not be used on wet surfaces, especially on heavy soils.
    • image of flat roller

    Cambridge Roller

    This type of roller has a ribbed surface and consists of a number of heavy cast iron wheels on an axle, each wheel is about 7cm wide with a ridge of about 4cm high, the wheels move independently.

  • They are used in seedbed preparation to crush clods and compact the soil to provide a smooth finish, they have a greater crushing and compacting effect than the flat roller.
    • cambridge rollers

    Crumbler Roller

    This is an open cage roller with a surface of spaced straight steel rods effective at crushing clods.

  • Some secondary cultivation machines may be fitted with a crumbler roller at the rear.
    • crumble rollers on exposed soil

    Session 2 - Land Preparation for Different Crops.

    Land Preparation

    Preparing a site for sowing a crop depends on factors that include:

  • Climate
  • Weather
  • Ground condition
  • Previous treatment
    • far away image of a tractor on exposed soil

    What Factors Influence Seedbed Preparation?

    One of the biggest factors that influences preparation of the seedbed is the intended crop.

    tractor, half on grass half on soil

    Winter Cereal

    Cereals generally perform better in the eastern parts of the UK due to drier harvest and more flexible drilling conditions.

  • In terms of yield and quality, wheat is favoured in heavier soils and barley does relatively better on light soils.
    • image of winter cereals with hill in background

    Seedbed for Wheat

    The objective of cereal seedbed preparation is to create a tilth (seedbed condition) consisting of fine material and egg-sized lumps. These conditions should allow the seeds to be drilled and easily covered with the surface remaining rough after planting.

    image showing field that has been prepared for wheat

    Surface Lumps

    The advantages of the lumps on the surface are:

  • Preventing siltier soils from ‘capping’ in wet winters.
  • Protecting base of cereal from the effects of cold winds.
  • Larger clods of soil make it easier for slugs to move through the soil and damage seeds and seedlings.
    • lumps on surface of soil

    Conventional Seedbed Preparation

    The conventional process for seedbed preparation is:

    Primary cultivation:

  • Subsoiling (if soil is compacted).
  • Ploughing.

    • Secondary cultivation:

  • Spring tined cultivation.
  • Power harrow.
    • equipment churning up soil

    Minimal Cultivation

    If conditions are favourable, minimal cultivation is possible i.e. surface cultivation without ploughing. In some cases no preparation may be needed where seeds can be directly drilled into stubble of previous crop.

    tractor in field with equipment attached

    Spring Cereal

    The climate and soil type requirements of spring cereals are the same as winter cereals.

  • The main difference is seedbed preparation as the tilth needs to be finer (very fine if grass and clovers are to be undersown). As the growing season is short this makes rapid crop establishment easier.
    • tractor on soil with equipment attached to rear

    Root Crops

    Root crops are predominantly grown in the arable areas along the east coast of the UK where lower rainfall allows for late autumn harvest.

  • As plant species which are physiologically different from cereals, they are used as break crops in predominantly cereal rotations. They can be grown in a variety of soil types, all with different advantages and disadvantages.
    • image of root crop begin to come to surface from soil

    How Should Root Crops Seeds be Sown?

    Root crops such as sugar beet, swedes and carrots have small seeds that often have to be placed in a pellet for sowing.

  • The ideal seedbed conditions for these crops are fine, level, firm and moist seed beds that give good seed contact for rapid germination. This is especially important when direct drilling or when low seed rates are used. Good early ploughing with uniform, well packed furrows will reduce secondary cultivation work in spring.
  • Deep cultivations should be avoided to keep frost mould on top and leaving the unweathered soil beneath the surface.
  • There should be no soil compaction below the seeds so that root can penetrate easily to exploit the soils’ potential and so that water can drain easily.

    • Potatoes

    An ideal climate in which to grow potatoes will provide:

  • Dry spring for good seedbed preparation.
  • Enough sunshine and moisture during the growing season.
    • potato crops

    Potatoes

    Potatoes are usually grown in ridges or beds therefore deep cultivation is needed but care should be taken not to bring unweathered soil and clods to the surface. The aim is to produce a tilth free from clods and stones.

  • The presence of clods and stones in the ridge slows down harvesting through having to manually separate the stones from the crop, it can also cause the potatoes (tubers) to be misshaped, decreasing the marketable yield.
    • ridges in field with tractor

    Destoner

    destoner on tractor in field

    Oil Seeds

    Both oilseed rape and linseed need fine soil particle size to ensure good soil contact with the small seeds for rapid germination since successful establishment is key to a high yielding crop.

  • A fine tilth also improves the efficiency of soil acting herbicides.
    • close up of rapeseed crop

    Winter Oilseed

    Winter oilseed rape is sown in late August and moisture conservation at this dry hot period is of essential, a firm seedbed will aid in conserving moisture.

  • Care should be taken to avoid soil compaction that reduces yields by limiting root development and subsequent water and nutrients uptake.
  • Minimum cultivations are usually carried out. The tilth also needs to be free from trash which would interfere with drilling operations.
    • tractor working the land

    Spring Oilseed

    A fine tilth can be achieved in seedbeds for spring oilseed rape and linseed by ploughing in the Autumn to produce maximum weathering effect through frost mould. The conventional process for seedbed preparation is:

    Primary cultivation:

  • Subsoiling (if necessary) 45cm deep to avoid compaction.
  • Plough.

    • Secondary cultivation:

  • Spring cultivation x 2.
  • Roll (Cambridge roller), this will consolidate to conserve moisture.
    • equipment cultivating land
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