Food

Food - SQA Key Definitions : 

• Agrochemicals - Chemicals such as fertilisers or pesticides used within agriculture to improve yields. 

• Algal bloom - A rapid increase or "explosion" in the population of algae in an aquatic system.

• Aquaculture - The farming of aquatic organisms in both coastal and inland areas involving interventions in the rearing process to enhance production.

• Bioaccumulation - the build-up of persistent, non-biodegradable pollutants within an organism or trophic level.

• Biological oxygen demand (BOD) - A measure of the dissolved oxygen that microorganisms consume while decomposing organic matter in a water sample. 

• Biomagnification - The increase in the concentration of persistent pollutants along a food chain, due to decreasing total biomass at higher trophic levels.

• Crop rotation - Planting different crops in a three or four year rotation to maintain the high yields needed without totally depleting the nutrients within the soil, reducing the need for fertilisers. 

• Diversification - Branching out from traditional farming to add new activities, such as farming different crops, farm shops, holiday accommodation, renewable energy or leisure activities.

• Eutrophication - Fertilisers or sewage enter a waterway such as a loch or river, and cause excessive plant and algal growth, causing major changes in the balance of the ecosystem.

• Genetic modification (GM) - Genetic changes made to alter the characteristics of crops by inserting a gene coding for a desired characteristic. 

• High-yield varieties - A crop variety that has been modified to increase its yield due to increased food demand. 

• Hydroponics - A method of growing plants without soil. Instead of drawing nutrients from the soil, plants are suspended in a water-based, nutrient-rich solution that delivers everything they need directly to their roots.

• Intensive agriculture - A farming practice that maximises the food yield obtained from livestock and crop plants.

• Marginal land - land that is not naturally suited for agriculture because it has limiting factors, such as being too steep or having very poor soil quality. 

• Mechanisation - The increased use of machinery in intensive farming. 

• Metabolisation - The biological process of breaking down a chemical toxin. 

• Nutrient enrichment - The genetic modification of a crop to increase its nutrient content. 

• Persistent organic compounds (POPs) - Toxic, carbon-based chemicals (usually pesticides) that are resistant to environmental degradation and are not easily metabolised within organisms.

• Pollutant - A contaminant that has been introduced into the natural environment, which can cause negative changes to the ecosystem.

• Selective breeding - The breeding together of organisms with desirable characteristics in the hope of improving these further. 

• Sustainability - The relationship or balance between social, economic and environmental issues.

• Sustainable development - Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

• Trophic level - A measure of the dissolved oxygen that microorganisms consume while decomposing organic matter in a water sample. 

Strategies to Increase Global Food Production

As stated previously, the increase in global population has put huge pressure on food production. 

Food demand is growing as a result of increasing population, changes in consumer demand (globalisation has increased the complexity of desired food), development and improving quality of life (diets have become more “westernised”, including much more meat and dairy) and climate change (extreme weather causes crop damage, food shortages and food price increases). 

In order to satisfy this increased demand, strategies are required to increase food production. 

These include :  

• Development of intensive agriculture. 

• Changes in technology. 

• Aquatic food production techniques.

Food Production : Agricultural Revolution

In the early 1700s, many Scottish landowners began a series of reforms designed to improve the quality of the farmland and to produce better harvests of crops. Waterlogged land was drained, new crops were introduced to Scotland, such as turnips and cabbage, and more land was given over to grazing sheep and cattle. 

New equipment, such as lighter, better ploughs that could be pulled by horses rather than oxen, was also introduced. While many of these reforms did much to transform the productivity of Scottish farming, these changes did have negative effects for some and brought an end to the traditional rural way of life. 

The Lowland and Highland Clearances caused massive population shifts across Scotland between 1730 and 1850, with people forced from their homes and villages to make way for sheep and cattle farming. 

Food Production : Modern Intensive Farming

Intensive agriculture is a farming practice that maximises the food yield obtained from livestock and crop plants. The following are examples of intensive farming techniques : 

To make farming businesses more economically and environmentally sustainable, other changes have been made to land management in recent years : 

Food Production : Changes in technology

Since the 'Agricultural Revolution', there have been major changes in the technology used in farming. 

These include : 

• Mechanisation

• Agrochemicals (fertilisers, pesticides)

• Irrigation

• Selective breeding

• High-yield varieties

• GM crops

• Hydroponics

Food Production : Mechanisation

Before mechanisation, the amount of food a farm could produce was limited by how much land a team of humans and animals (usually horses or oxen) could plough before the planting window closed. Modern machinery enables farmers to plant thousands of acres in a matter of days rather than months. This is crucial for hitting the "optimal window" for soil moisture and temperature. 

In terms of harvesting, mechanisation also plays a huge role. A single modern combine harvester can harvest as much grain in one hour as 100 people could harvest by hand in a week : 

By reducing the need for rural labour, mechanisation also allows for a smaller percentage of the population to feed a larger urban population. In the early 1800s, approximately 70-80% of people worked in agriculture; today, in many developed nations, it is less than 2%. Therefore, without mechanisation, there would be no way to grow sufficient food for current populations. 

Mechanisation Case Study : Smart Tech

Modern mechanisation isn't just about being 'big', it's also about being precise. Using GPS and A.I. guided systems, farmers can now treat every individual plant or animal as a unique data point.

Food Production : Agrochemicals (Fertilisers)

The use of agrochemicals (chemicals such as fertilisers and pesticides) is used to boost plant production in farms globally. They can come from natural sources, but usually are artificial chemicals that are either added to the soil or sprayed directly onto the plants.

Fertilisers are chemicals that have been added to the soil to replace essential nutrients lost due to previous farming. The key chemicals required for plant growth are Nitrogen (for leaf and stem growth), Phosphorus (for root development) and Potassium (for fruit development and disease resistance). 

Fertilisers, however, can run off fields and into rivers, causing eutrophication (when the nutrients cause a population explosion of photosynthetic organisms in a waterway).

Eutrophication occurs when fertilisers or sewage enters a waterway such as a loch or river, and causes excessive plant and algal growth, causing major changes in the balance of the ecosystem. In severe cases, eutrophication can cause the complete collapse of an ecosystem. 

As can be seen in the above graph, as the nutrient levels in a loch increase, the huge increase of Algae growth comes at the expense of all other aquatic plant life. 

This thick blanket of algae prevents sunlight from reaching the plant life below the surface, preventing photosynthesis and therefore killing the Pond Grasses and Phytoplankton present. 

When the algae die, their remains are decomposed by bacteria in the water, depleting the oxygen levels in the water, killing aquatic life such as fish.

This completely disrupts the Food Web, with the potential to cause a collapse of the entire ecosystem, leaving behind a dead, empty loch. 

The process of eutrophication can also occur in marine environments:-

Food Production : Agrochemicals (Pesticides)

Pesticides kill organisms that would otherwise compete for crop plants for nutrients or eat the plants themselves. However, these pesticides can kill non-target species (such as Bees) or cause problems in the food web.  

Most chemical pesticides are classed as 'Persistent Organic Pollutants' or POPs, as they are resistant to breaking down in the environment. Unlike many other pollutants that disappear after a few days or weeks, POPs can remain intact for decades. Because they are "organic" (carbon-based), they bond easily with organic matter, specifically the body fat of animals and humans. 

These chemicals are also not easily metabolised (broken down) by the organisms, making it difficult for the organisms to excrete these toxins. 

Pesticides applied in fields can enter waterbodies, where aquatic invertebrates absorb them through their skin, gills or lungs. The pollutant is stored in the tissues of the organism at a rate faster than it can be metabolised or excreted, in a process known as 'bioaccumulation'. 

As a consumer eats more contaminated prey, the level of pollutant gradually builds up in its tissues. This predator will in turn be consumed as prey, and the concentration of the pollutant will increase as it is passed up the food chain, eventually reaching toxic levels. The dietary uptake of the pollutant and its movement through trophic levels is known as 'biomagnification'.

These POPs have a range of toxic effects, including increasing risks of cancer, birth defects, and immune system failure.

Agrochemical Case Study : Neonicotinoids 

Neonicotinoids are a class of pesticides (chemicals that are used to kill insects and other pests) that have been widely used to protect crops from damage. These pesticides have a similar chemical structure to Nicotine and similarly affect the body. When the insect takes in the Neonicotinoids, they bind to parts of the nervous system, blocking parts of it. In a large enough dose, this causes paralysis and death.

They are very effective because they are systemic. This means that the Neonicotinoids can be added to water, and the crops will take it up are spread it through the entire plant. This is better than traditional spraying, as if you then water the plants, the sprayed chemical is washed off the plants.

It is this systemic approach that is the problem for Bees. The Neonicotinoids enter the Nectar of the flowers, and therefore the Bees will also ingest it. This is made worse by Bees then favouring flowers with Neonicotinoids in their nectar, just like a smoker addicted to cigarettes.

The level of Neonicotinoids in the nectar is low, so it doesn't generally kill the Bee instantly, but as they bioaccumulate in the Bee's tissues, they have been shown to have the following long-term effects : 

• Lower life expectancy

• Reduced flying ability

• Ability to learn navigational directions

• Lower resistance to viruses

• Lower resistance to Mite infestations

• Colonies at greater risk of Colony Collapse Disorder (where otherwise healthy colonies fail unexpectedly)

Neonicotinoids have been banned for use in the UK since 2013 under EU law, in an effort to protect Bees and other natural pollinators, but this has had a negative impact on farming, so it is a controversial issue that is under constant review. 

Food Production : Irrigation

Water is vital to the survival of all organisms, whether plant or animal, and this makes ensuring that farmers have sufficient water throughout the year a priority. Irrigation is the artificial application of water to land or soil. It is used in the growing of crops, the maintenance of landscapes, and the revegetation of disturbed soils in dry areas or during periods of inadequate rainfall. 

In modern farming, irrigation has moved from supplementing rain to a highly engineered system that controls the entire lifecycle of a plant. There are four key methods of irrigation within farming :

Food Production : Selective Breeding

No modern crop plant or livestock animal looks the same way as their wild ancestors. Humans have spent thousands of years breeding together organisms with desirable characteristics in the hope of improving these further, in a process known as 'Selective breeding'. Selective breeding has allowed farmers to grow plants and animals with improvements in size, flavour, speed, or docility.  

The classic example of this in plants is the 'Brassica' Family. The 'wild' ancestor of many major green-leafed vegetables can be traced back to a single species of wild plant, Wild Mustard (scientific name - Brassica Oleracea) : 

The classic example of selective breeding in animals is the 'Dog' Family. The 'wild' ancestor of all dogs is the Grey Wolf (scientific name - Canis Lupus) : 

Food Production : High-Yield Varieties

In the early 20th century, population growth began to outpace food production, raising major concerns about global food security. One of the ways scientists worked to prevent this was by developing 'High-Yield Varieties' (HYVs) of crops, especially wheat and rice. 

Traditional wheat and rice plants were tall and thin, so when farmers added more fertiliser to boost yield, the now top-heavy plants would buckle under their own weight and rot on the ground. To prevent this, scientists selectively bred the plants to produce shorter, thicker stems, which were capable of supporting the weight of the increased yield. 

The photo below shows how the height of the most commonly used strains of wheat has changed over the last ~100 years :

These 'semi-dwarf' varieties are classed as HYVs as they could produce 3-4 times more grain than traditional varieties. HYVs are credited with saving over a billion lives globally due to famine prevention. 

These varieties do have a negative side, however. This is due to their increased environmental impact due to increased water and fertiliser requirements, as well as heightened disease risk due to the crops' lack of genetic diversity. 

Agronomists advise farmers on soil management to improve crop production. They investigate all factors that could affect crop growth and yield and tell farmers the practices to use to maximise profitability for their farm.

Agronomists look at soil composition, water levels and drainage, introduce fertiliser programmes, and create treatment plans to keep crops free of pests and weeds without harming the environment. They have a good understanding of the latest research and making sure that all government legislation is complied with.

Food Production : Genetically Modified (GM) crops

Scientists can alter the characteristics of crops by inserting a gene coding for a desired characteristic. This can include disease resistance, higher yield or even those coding for a richer, better taste.

Examples include :

However, many people will not eat GM crops as they worry that they will harm their health (no peer-reviewed scientific study has shown any risk), and many conservationists worry that GM crops will crossbreed with native species to produce hybrids.

Since 2015, the Scottish Government has banned the growth of GM crops across Scotland, citing concerns of damage to the Scottish Food 'Brand', which is seen as natural and pristine, as well as concerns regarding the long-term impact of GM changes, especially focusing on the risk of cross-pollination to wild plants. 

Further research is ongoing, and changes may be made going forward. 

Food Production : Hydroponics

Hydroponics is a method of growing plants without soil. Instead of drawing nutrients from the soil, plants are suspended in a water-based, nutrient-rich solution that delivers everything they need directly to their roots. Hydroponics is used to maximise efficiency, allowing for "vertical farming" in urban centres and year-round harvests in climates that otherwise couldn't support agriculture. 

A hydroponic system replaces the need for soil by using technological alternatives :  

• Nutrient delivery : Water is mixed with the required proportions of nitrogen, phosphorus, potassium, and other nutrients, which are circulated directly to the roots. 

• Root Support : Plants are held in place by "inert media" such as coconut coir or perlite. These materials don't provide food; they simply give the roots something to grip. 

• Oxygenation : In soil, roots get oxygen from air pockets. In hydroponics, oxygen is bubbled into the water or delivered by misting the roots only, to prevent the plants from drowning.

Below are examples of companies which operate in Scotland, using hydroponics for food production : 

Aquatic Food Production : Aquaculture

Aquaculture is the farming of aquatic organisms in both coastal and inland areas involving interventions in the rearing process to enhance production. It is the fastest growing food-producing sector globally and now accounts for 50% of the world’s seafood.  In Scotland, Aquaculture contributes £1.8 billion to the economy and employs over 9,000 people directly, with many more in the supply chain. 

The video below shows an overview of Aquaculture, including some of its environmental impacts :

Aquaculture in Scotland involves rearing finfish (for example, Salmon or Trout) in both freshwater and the marine environment as well as Shellfish and Seaweed. 

Finfish are normally hatched and reared through the early stages of life in land-based hatcheries and then transported to freshwater or marine cage sites. These cages are normally 90-110 meters wide and 15-20 meters deep, holding the amount of water equivalent to approximately 20 swimming pools. Cages are anchored to the seabed using ropes, chains and heavy specialised anchors. Each cage will hold, on average, between 45,000-55,000 fish. 

Traditional methods of Aquaculture rely on large quantities of antibiotics and pesticides (to reduce parasites) as well as large quantities of feed-fish, usually from wild-caught sources. Artificial pigments can also be used to make the meat appear a more appetising colour.

Other environmental concerns can be seen in the infographic below : 

Sustainable Aquaculture : Integrated Multi-Trophic Aquaculture

Integrated Multi-Trophic Aquaculture  (IMTA) is a form of polyculture which mimics the nutrient flows in natural systems by using the waste from one part of the system as input to another. In conventional salmon farming, around 60% of the nitrogen in the salmon feed is lost to the wider ecosystem and can have negative ecological impacts if present in high concentrations, on top of the waste matter from the fish themselves.

In IMTA, seaweed and shellfish are grown close to the fish cages in order to maximise uptake of the nutrients that would otherwise be lost. The shellfish benefit from the organic matter and the seaweed from the soluble nutrients, including nitrogen. 

These can then either be sold on for profit, or if the system is used a sustainably as possible, the shellfish can be used to produce feed for the fish, completing the cycle:-

Animal Nutritionists are scientists who analyse the nutritional value of feeds and provide dietary advice to staff from all industries working with animals, such as agriculture, animal care, equine and aquaculture. 

Animal Nutritionists promote a better understanding of the effect of diet on the health, wellbeing and productivity of animals. They provide advice and information on animal nutrition and design and evaluate the diets of the animals working with. Some Animal Nutritionists choose to specialise in one type of animal. Others look at nutritional disorders and find ways to prevent the animal from suffering by formulating new food programmes.

Aquatic Food Production : Marine Fisheries 

Fishing is the hunting of aquatic organisms (fish, shellfish etc.) in coastal areas and the deep sea using a range of methods, usually involving nets or cages. Seafood is Scotland’s second largest export and was worth approximately £560 million in 2021 : 

The Marine Directorate (part of the Scottish Government) is responsible for controlling the activities of all fishing vessels operating within the Scottish zone, as defined by the Fishery Limits Act 1976 and the Scotland Act 1998.

This covers the North Sea and west of Scotland out to 200 nautical miles. It is also responsible for managing and controlling the activities of all Scottish vessels wherever they may fish, including how much of each type of fish they may land (known as a fishing quota), in order to prevent overfishing. Overfishing occurs when fish stocks are reduced to below acceptable levels. The results of this not only affect global food security, but also marine ecosystems and the social and economic well-being of the coastal communities that depend on this activity for their livelihood. 

By setting fishing quotas on the maximum amount of fish that can be landed, fishing (in theory at least) can be kept at a sustainable level. Quotas do this by ensuring a large enough wild population to replenish the numbers that have been removed by fishing. 

Fishing Seasons help keep fishing at a sustainable level in a similar way. In Scotland, Salmon can only be legally caught in rivers between the 11th of February and the 31st of October. This is because Salmon spawn (reproduce) over the winter months. By preventing fishing during this time, the Salmon can reproduce without interference and stress, resulting in higher numbers of healthy fish. 

The Marine Directorate also implement the Marine Protected Area (MPA) network involving 231 sites covering 22% of Scotland’s marine environment. MPAs are areas where potentially destructive human activities are regulated to protect natural and cultural features. MPAs can also be beneficial to fisheries, creating safe havens for commercial species to reproduce, often followed by a spill over into surrounding areas. 

The map below shows how the waters around Scotland are zoned. Fishing is either restricted or banned in all coloured areas :