Arable
In 2005 approximately 15% of agricultural land in
Scotland was designated as arable. The majority of arable
farming takes place in the east of Scotland where the most fertile
land tends to be and where the climate is more suitable.
Barley is the most common arable crop grown in Scotland,
although other crops such as wheat, oats, oilseed rape and potatoes
are also commonplace. Most cereal crops such as wheat and barley
are planted in either spring or autumn.
In Scotland the majority of the barley crop is planted in spring
and usually harvested from mid August weather permitting. The
remainder, winter barley, is planted in the autumn and harvested
the following year, usually from July.
Issues which affect arable farming include:
Nitrate leaching
Nitrate is an essential nutrient required for plant growth. As
well as occurring naturally in soil, nitrates are supplied in
chemical fertilisers, livestock manures and slurries and often
organic materials spread on land. The loss of nitrogen compounds,
such as nitrates, can cause pollution where they are allowed to
enter watercourses or groundwater.
Although high levels of nitrates are of concern with
respect to drinking water supplies, the main environmental
concerns about nitrates relate to eutrophication of the water
environment.
When crops are growing, nitrogen, in the form of ammonium and
nitrate, is readily absorbed from the soil. Once plant growth
begins to decline, any nitrates that remain or continue to be made
available in the soil (for example through the application of
fertiliser or slurry), are vulnerable to loss. This is especially
the case when such nitrate is below the root zone and where soils
are light or sandy.
However, losses of nitrates can occur in other soil
types due to their high solubility in water. Nitrates are
particularly prone to loss through leaching. This is where nitrates
dissolve in the water as it passes through the soil and enter field
drains or watercourses. The quantity of nitrates lost in this way
will depend on the amount of nitrates in the soil and the movement
of water through the soil. This will be further influenced by the
soil's texture and structure. Sandy soils for example, which are
low in organic matter and have a poor water holding capacity, tend
to suffer more from nitrate leaching than well structured, clay
soils.
To reduce the quantity of nitrates lost through leaching it is
important that applications of fertiliser are closely matched to
crop requirements. The quantity of nitrogen already available
in the soil through deposition from grazing animals, crop residues
and from any applications of manures or slurry, needs to be taken
into account.
The timing of applications is also important. Nitrates are very
soluble in water and any nitrates present in the soil, in
excess of crop requirements, will be prone to loss. Crop
requirements will vary significantly through the year and will be
influenced by crop type, growth stage and weather conditions.
Farmers with land in Nitrate Vulnerable Zones (NVZ) are required to
comply with Action Programme Regulations, enforced by the Scottish
Government. Separate guidance is available from the Scottish
Government website 
on
cross compliance .
SEPA's role in the EC Nitrates Directive is restricted to
monitoring surface and groundwater and reporting the data to the
Scottish Government. SEPA also assesses whether agricultural
nitrates are causing, or have the potential to cause,
eutrophication.
By carefully targeting applications of nitrogen to crop
requirements, fertilisers will be used to maximum efficiency and
the risk of environment pollution will be greatly
reduced. The
4 Point Plan (4PP) 
and
PEPFAA Code 
offer guidance on this.
Pesticides
Arable pesticides include herbicides, fungicides and
insecticides and are commonly used in agriculture to control a wide
range of weeds, diseases and pests. Herbicides are usually applied
at the start of the growing season to kill weeds and prevent them
competing with the emerging crop for light, moisture and nutrients.
Insecticides and fungicides tend to be used as required throughout
the crop production cycle.
Most pesticides are made available in a concentrate form. This
is usually diluted with water on-farm to create a solution which is
then sprayed onto the crop as a fine spray, often from a
tractor-mounted or a trailed sprayer, but also from self-propelled
sprayers.
Although pesticides are targeted at relatively few specific
organisms, their use can have negative impacts on the wider
environment, affecting non-target organisms and aquatic
ecosystems.
Ground and surface waters are vulnerable to pollution by
pesticides and can raise concerns for public health
where supplies are used for drinking water.
Pesticide pollution can arise from both steading and field
sources. Even small amounts of pesticide can result in a
significant pollution event, for example, from drips and spills of
concentrate onto concrete at the farm. Minor spills or splashes
during the mixing of pesticide solution, or any drips or leaks
from the sprayer, can be sufficient to cause pollution if they
are washed into farm drains or watercourses.
Guidance on how to minimise the risk of pesticide pollution can
be found within the
PEPFAA Code 
and the Code
of Practice for Using Plant Protection Products in
Scotland . SEPA is represented on the UK
Voluntary Initiative (VI) and Scottish Implementation Group,
alongside, NFUS, Scottish Government Environment Directorate, SNH
and farm assurance schemes.
Farmers are encouraged to use guidance issued under The
Voluntary Initiative on crop protection
management plans, the National Register of Sprayer Operators
(NRoSO) and National Sprayer testing
scheme. Scottish
Quality Cereals (SQC) is responsible for
ensuring that standards for food safety and environmental measures
are followed.
SEPA has also actively participated in the development, through
UK research, of guidance and legislation on bio-beds. These systems
can significantly reduce the risk of pesticide pollution arising
from the handling of pesticides and pesticide sprayer wash down
etc., see the voluntary
initiative .
Soil erosion
Loss of agricultural soils through erosion affects productivity
and impacts the water environment. Build up of silt on river beds
and increased levels of sediment in the water can affect aquatic
habitats and organisms. Eroded soil particles can transport
pollutants such as pesticides and phosphates, which can have a
negative impact for the water environment.
Certain soils are more prone to erosion than others. There are,
however, measures and practices that farmers can adopt to reduce
the risk. Guidance on how to minimise the risk of soil erosion can
be found within the
PEPFAA Code 
and the Farm Soils
Plan .
Waste
Agricultural waste can pose significant risks to the environment
and human health if not managed appropriately. The types and
quantities of wastes will vary between farms. Common types of waste
produced on farms will typically include materials such as
packaging, tyres, oils and silage plastics etc.
Guidance on minimising waste produced on the farm and further
information is available from our agricultural waste guidance.