The document discusses soil cultivation techniques including single digging, double digging, and rotavation. It describes the benefits and limitations of each approach. No-dig systems are also covered, noting their benefits of less work and not damaging soil structure, but also limitations like not remedying existing issues. The document also discusses how water moves through soil and is lost, symptoms of poor drainage, and techniques for maintaining appropriate soil moisture levels including irrigation practices and using organic matter.
2. Quiz
Tests last two week’s material.
15 minutes, test conditions.
3. Quiz Answers
Surface capping arises when the particles in the soil
(particularly in silty soils) bond together. This means that
water cannot soak into the soil and air cannot enter. This
prevents seedlings from breaking through the soil
surface. It also means that roots cannot get the oxygen
they need to respire.
Cultivation pan may either be made up of iron leached
from the top soil and bonded to clay particles, or of stones
that have settled out of the top soil during cultivation.
This prevents the roots of plants from penetrating into the
sub soil and may lead to poor establishment. Cultivation
pan may be rectified by double digging
4. Quiz answers continued
Question 2 – (a) and (c)
Question 3 – (c)
Question 4 – (a)
Question 5 – Sandy soil
Question 6 – 40% sand, 40% silt and 20% clay.
Question 7 – (b)
Better than 3 or 4 out of 7 is a good result at this
stage. Less than that you need to review your
notes again.
5. Learning Outcomes
2.5 Describe the benefits and limitations of basic cultivation techniques.
2.6 Describe the use of pedestrian operated soil cultivating machines
2.7 Describe the management of minimal cultivation systems e.g. no dig systems.
3.6 Describe two methods by which soil structure can be improved and two
practices which damage soil structure, to include: incorporation of organic
matter; addition of inorganic soil improvers; compaction; and cultivation
techniques.
3.7 State what is meant by ‘surface capping’; explain how it may happen and what
effects it can have on plant establishment and growth.
3.8 Describe how a cultivation pan can be formed, what effect it has on plant
growth, and how it can be rectified.
4.1 Describe the relationship between air and water content in the pore space of
soils and growing media.
4.2 Explain the importance of an appropriate balance between air and water for
the healthy growth of plants.
.4.4 Identify a range of management techniques for maintaining soil moisture at
appropriate levels
4.5 Identify the surface symptoms of poor drainage, to include: standing water,
surface run-off and indicator plant species.
6. Cultivation techniques
Single digging – used for previously
cultivated soil with good structure.
Double digging – for uncultivated soil or
to improve clay soils or those with
cultivation pan, poor drainage etc.
Rotavation – for larger areas. Safety
considerations – PPE, maintenance,
correct operation.
7. Benefits and limitations -
digging
Benefits Limitations
Improves the structure of the soil – Disturbs natural structure of the soil and
allows access for water and air may harm beneficial organisms
Exposes pests to predators and the Can damage soil structure if the texture
weather. Allows clay clods to be frosted. and wetness of the soil are not taken into
account.
Breaks up cultivation pans and improves Brings dormant weed seeds to the
drainage. surface where light will stimulate
germination
Incorporates organic matter and buries Leaves a bare surface which may lead to
crop residues and weeds leaching or capping
8. Benefits and Limitations -
Rotavation
Benefits Limitations
Less hard work than manual digging Expensive to buy or hire, safety
considerations.
Makes larger areas more manageable Can produce a very ‘fluffy’ tilth with large
air pockets – will need raking and
possibly firming before planting
Provides a good tilth in a short period of Will not effectively break up hard or stone
time pan and may cause a cultivation pan by
smearing wet clay soils.
Has most of the benefits of single Not ideal for incorporating organic matter
digging.
9. No Dig Systems
Benefits Limitations
Less work than traditional digging Will not remedy soil structure problems
approaches to soil management like hard pan or poor drainage
Does not damage soil structure where Large amounts of organic matter are
this is already good required
Weed seeds are not brought to the Some risk of long term soil acidification
surface – which reduces beneficial organisms
Soil organisms are not disturbed Pests may build up in the soil as the
larvae are not exposed by winter
digging
12. Drainage
Symptoms of poor drainage – standing
water; gleys; indicator plant species;
surface run off.
Cures – double digging; incorporate
coarse organic matter; install tile drains or
sub-soiling (clay soils) on large areas.
13. Water retention and irrigation
Irrigate to restore capillary water – so add enough to
do so when needed rather than water little and often.
Mulches and timing of irrigation can reduce
evaporation. Water at the roots – not on the leaves
and bare soil.
Organic matter acts like a sponge and creates
aggregates with both intermediate and macro pores.
14. Learning Outcomes
2.5 Describe the benefits and limitations of basic cultivation techniques.
2.6 Describe the use of pedestrian operated soil cultivating machines
2.7 Describe the management of minimal cultivation systems e.g. no dig systems.
3.6 Describe two methods by which soil structure can be improved and two practices
which damage soil structure, to include: incorporation of organic matter; addition of
inorganic soil improvers; compaction; and cultivation techniques.
3.7 State what is meant by ‘surface capping’; explain how it may happen and what
effects it can have on plant establishment and growth.
3.8 Describe how a cultivation pan can be formed, what effect it has on plant growth,
and how it can be rectified.
4.1 Describe the relationship between air and water content in the pore space of soils
and growing media.
4.2 Explain the importance of an appropriate balance between air and water for the
healthy growth of plants.
.4.4 Identify a range of management techniques for maintaining soil moisture at
appropriate levels
4.5 Identify the surface symptoms of poor drainage, to include: standing water, surface
run-off and indicator plant species.
