Farm Health, Safety, Pollution and Waste

Useful in the wrong place

This part of your specification looks like two subjects bolted together. Farm safety on one side, pollution and waste on the other. It is really one idea seen twice. Slurry is fertiliser, and it becomes a problem when it is in the wrong quantity or the wrong place. Silage effluent is feed that leaked. The medicine that treats a sick animal is the residue that must not reach the food chain. Machinery is capability, and it stops being safe the moment attention lapses. Nothing on this list is dangerous in itself. Every one of them is something useful that has escaped where it belongs. That is why safety and pollution sit on the same node: they are the same discipline, applied to people in one case and to water in the other. Hold onto that sentence, because every control technique later in this module turns out to be a way of putting material where it is useful instead of where it does harm.

Words for hazards and pollution

Five terms this specification uses precisely. The first two are not synonyms, and the cycle you meet next depends on the difference.

Hazard to control

The stage everyone forgets

A farm identifies its hazards, works out how serious each risk is, and puts controls in place. Your specification names a fourth stage. What is it, and why is it there?

• Monitor and review, because a farm changes and a control that worked once may stop working
• Record it, because the paperwork is what gets inspected
• Train the staff, because controls only work if people know them
• Insure against it, because some risks cannot be removed

Storing what treats and what kills

Agrichemicals and veterinary medicines are both stored under rules, and the rules are not the same because the substances do different jobs. Both are examples of the spine: useful things that must stay where they belong.

Which two are storage failures

Select the TWO practices that break the rules for storing agrichemicals and medicines safely.

• Pouring a concentrate into an unlabelled drinks bottle so it is easier to carry
• Keeping veterinary medicines on a shelf in the open feed store
• Recording the date an animal was treated and which medicine was used
• Wearing protective equipment while mixing as well as while spraying

Why slurry is treated so carefully

Slurry is a genuine fertiliser and a genuine hazard, and understanding why makes both halves of this node make sense. As it is stored it breaks down, and that breakdown releases gases. The dangerous moment is disturbance: stirring or agitating a tank releases gas quickly, and in an enclosed or poorly ventilated space that can produce an atmosphere nobody should be in. So the controls are all about the same thing. Stir only with buildings ventilated and opened up, keep people and animals well away while it is being done, never enter a tank or a confined space where gas can collect, and treat the crust on a store as a cover rather than a surface. Machinery works the same way: it is a hazard because it can move or start when somebody is near it, so the control is to stop the engine, remove the key and apply the brake before going anywhere near a moving part. Notice the pattern in both cases. The control does not remove the useful thing. It keeps it where it belongs, which is exactly what this whole node is about.

Where the pollution comes from

The specification names several sources of farm pollution. _____ effluent is the liquid running from stored silage. Excessive _____ and animal waste washing off land carries nutrients into water. Air pollution arises from _____, machinery causes _____ pollution, and dirty _____ water runs from areas where animals and vehicles have been. Every one is a useful material that has left the place it was meant to be.

A lake worth not polluting

You have already met Lough Neagh elsewhere in this course as a designated site, protected for what lives in it. Take that as given here and turn it round: a place worth designating is a place worth not polluting, and Lough Neagh is the example your specification uses for what happens when nutrients reach water in quantity. The sequence is the thing to learn. Fertiliser is applied to land in excess of what the crop can take up, or animal waste reaches water. Rain carries those nutrients into the lough. Nutrients are exactly what algae need, so algae grow rapidly and in enormous numbers. That growth does not last, because algae die. Bacteria then decompose the dead algae, and decomposition consumes oxygen from the water. With the oxygen depleted, fish and other animals that need it cannot survive. Northern Ireland manages this through the EU Nitrates Directive and the designation of Nitrate Vulnerable Zones, which restrict how much nitrogen may be applied and when it may be spread. Read that chain again and notice where the damage is actually done.

The chain, in order

Put the stages of eutrophication into the order in which they happen. Getting the order right is what the marks are for.

• Excess fertiliser or animal waste is applied to land
• Rain washes the nutrients off the land and into the water
• Algae grow rapidly, because nutrients are what they were short of
• The algae die
• Bacteria decompose the dead algae, using up oxygen as they do so
• Oxygen in the water is depleted and fish die

The claim that stops too early

Four sentences about eutrophication. Select the ONE that gets the cause of the fish deaths wrong.

• Nutrients reaching the water allow algae to grow rapidly.
• The algae themselves use up the oxygen, and that is what kills the fish.
• Bacteria decomposing the dead algae consume oxygen from the water.
• Fish die because the water no longer holds enough oxygen for them.

Reading a river sample

A survey of a stretch of water records mostly worms and leeches, and none of the mayfly, caddisfly or dragonfly nymphs found upstream. What can you conclude, and why?

• Oxygen is low here, because the species present are the ones that tolerate low oxygen and the ones absent are those that need it
• The water is clean, because invertebrates are living in it
• Nothing, because you would need a chemical test to say anything about the water
• The fish have eaten the mayfly and caddisfly nymphs

Named lists drill

Five quick questions on the terms this specification expects you to have exactly. Three lives.

State why the technique works

Assemble a sentence explaining what a trailing shoe or shallow injection actually achieves.

Spreading day

A farm inside a Nitrate Vulnerable Zone plans to spread slurry on a sloping field next to a stream. Take the decisions in order.

• Rain is forecast for tomorrow. What does that change?
• The tank needs stirring before it can be emptied. What comes first?
• Two application methods are available. Which reduces loss and runoff, and why?
• The job is done safely. What does the risk assessment cycle require now?

Explain the risk and the runoff

A farm wants to reduce both its safety risks and its impact on a nearby watercourse. Explain what it should do and why, using the named terms from this topic.

• Name the four stages of the risk assessment cycle in order
• Explain the difference between a hazard and a risk, using a farm example
• Describe two control measures for slurry and say what each one prevents
• Name three sources of farm pollution
• Explain the eutrophication chain, making clear what actually depletes the oxygen
• Describe two techniques that reduce pollution from slurry application and explain how each works
• Explain how invertebrate indicator species let you judge water quality without measuring oxygen directly
• Finish by explaining why safety and pollution belong on the same topic