3.2 Agricultural systems

syllabus_link_buttonDescribe in general terms the main features of an agricultural system: inputs, processes and outputs.


Farming as a System

Agriculture is a form of industry and so has inputs, processes and outputs.  Different farming techniques and purposes will have different proportions of each.  Typical examples for arable farming are:

agri_inputs agri_processesagri_outputs


syllabus_link_buttonDescribe the influence of natural and human inputs on the processes and outputs of a large-scale system of commercial farming and small-scale subsistence farming. 

Studies should include natural inputs (relief, climate and soil) and human inputs (economic, social and sometimes political). Their combined influences on the scale of production, methods of organisation and the products of each system should be studied.


Large Scale Commercial Farming

Large scale commercial farming increasingly occurs as companies or farmers look to reduce the cost of farming by increasingly the scale or production and mechanising their methods.

Palm Oil Plantations: Indonesia

monoculturePalm oil plantations have been established over vast areas in many tropical regions, generally developing countries.

They require large land input but a relatively low labour force.  A combination of machinery and labour is used in the harvesting.  Fertilisers are used to replenish the nutrients depleted by this type of monoculture farming.

The output is purely for sale and is of little benefit to the local populations. Palm oil plantations are damaging to biodiversity in rainforest regions since they d not provide a habitat for many species.



Banana Plantations: Costa Rica

bananasBanana plantations cover many of the lowland areas of Costa Rica and Panama.

Labour is relatively cheap in these regions and the plantations use a mixture of capital (pulley systems to move the banana bunches, irrigation, fertilisers and pesticides) and labour to plants and harvest the bananas.

The warm wet climate is ideal for growing bananas and much of the land is fertile soil deposited on floodplains.



Wheat Farming: South East England

Corn & wheat farming in developed countries is highly mechanised with a very small labour force.  Covering vast areas of fertile and relatively flat land the ploughing, sowing and harvesting are all mechanised.  Fertilisers, pesticides and irrigation are all required to maximise the output.  Again the output is purely for sale. This type of farming has high capital and land input and high output levels.


Case Study: Commercial Chicken Farming, Hereford, UKcapital_intensive

2 long sheds containing 90 000 chickens with a turn-around period of 6 weeks (time from hatching to being sent to the supermarkets).  The sheds are entirely automated with computer controlled climate, feeding and water supply.  The chickens are weighed by pressure pads in the floor as they approach the feeders and the correct amount of grain for their weight is dispensed.  After 6 weeks when the chickens have matured the collection is outsourced to a team of Polish chicken catchers.  Arriving in the night, they use UV lighting in the shed to see the chickens in the dark and collect them 10 at a time.  The sheds are then cleaned and sterilised in 2 weeks (outsourced again) before the next batch of chicks arrives.  This is an intensive industrial approach to farming which has high capital input and requires large volumes to be profitable. The output is sold to some of the UKs leading supermarket chains.


Small  Scale Subsistence Farming

subsistence rice farming
subsistence rice farming

Subsistence farming is practised extensively in rural areas of East Africa.  Families with small plots of land often on hillsides with rocky soils grow crops such as casava to feed their families.  Casava is similar to Yucca, a tuber like potatoes and provides a filling carbohydrate based meal.  It grows in poorer quality soil and can withstand less water than potatoes need.  Whilst this staple provides energy it does not have significant nutritional content.  Subsistence farmers here often keep chickens to provide eggs and meat for protein. Many farmers here also grow tomatoes and a small selection of other vegetables in the land available.  They have very little left over to trade for other products.  Where water is available rice is grown on a small scale again with labour being the  main input.

Subsistence farming has very low capital input,  basic tools and seeds are the main ones.  Labour is most significant factor as the families work the land.  Outputs are low.


syllabus_link_buttonRecognise the causes of food shortages (natural, economic and political factors). There should be an awareness of the effects of these natural problems on selected areas within LEDCs.  

Causes of Food Shortages

Rising Demand for Food

On the most basic level food shortages occur when the supply food does not meet the demand for food.  One of the most significant factors in this is that rising populations globally are leading to increased global demand for food.  When the demand for food outstrips the supply the result is rising prices of food.  It is often the poorest people who are affected most since they can least afford the extra cost.


Factors affecting the supply of food

Soil exhaustion: this occurs when the nutrient and mineral content of soil has been significantly depleted.  Soils need time to recover after they have grown crops and traditionally farmers would rotate the crops grown and leave parts of the land empty (fallow) for a year periodically.  Different crops take different nutrients from the soil so rotating the crop reduces the rate of soil exhaustion.  As land has become increasingly intensely farmed soils have become more at risk.  Commercial farms add fertilisers to counter this but subsistence farmers are unlikely to be able to afford this and face reduced yields from their crops.

Drought: population growth, industrialisation and commercial farming have all increased the demand placed on freshwater supplies.  Many areas are now experiencing increased occurrences of drought.  California is dealing with the worst drought for over 50 years presently (2014).  Underground water stores (aquifers) have been seriously depleted in parts of India due to unsustainable use for irrigation.  Phoenix, USA has been depleting its groundwater by 3 meters a year and now has to import water.  Without irrigation, the quantity of food grown will decrease.

Floods: floodplains are ideal locations for arable farming with flat land and fertile soil. These areas are naturally prone to flooding but modification of river systems, deforestation upstream and large urban areas creating impermeable surfaces have all contributed to increased instances of large floods.  Floods are damaging to crops as they saturate the ground often causing most crops to rot or suffer from excess water.  Livestock is also severely affected as animals either drown or need to be moved to alternative locations that can also provide them with food.

Economic factors: globalisation has impacted agriculture in  a major way.  Virtually all countries are involved in the global trade of food, importing and exporting different products.  Many developing countries have allowed significant proportions of their land to be used for growing export crops to boost their own economies.  Whilst this may bring money into the country it also reducing the land available for producing food to supply their own population.  Kenya has large scale commercial farms growing vegetables and flowers purely for export to European markets, while many people in the north of the country suffer from food shortages.

War & conflict:  as well as the huge human and economic cost, conflict can severely impact on food supplies.  Wars (international or civil) involve many of the most able males of working age.  A consequence of this is often a reduce labour force for agriculture. The longer term effects of war such as increased death rate generally of the most physically able men impacts on food supplies in areas that rely largely on subsistence agriculture.


syllabus_link_buttonThe effects of food shortages in encouraging food aid and measures such as those of the ‘Green Revolution’ to produce more food should also be considered.

Effects of Food Shortages

Food shortages have the obvious effect of malnutrition and in severe cases starvation.  Famines in Ethiopia have been well documented as population suffer diseases such as mamasrus and kwashikori from lack of food and lack of nutrition in their diet.  Large-scale refugee movements have occurred and huge camps established in Kenya to help deal with the problem.  International aid agencies such as oxfam, the Red Cross and Cafod are often involved aswell as international agencies such as the United Nations.

The United Nations World Food Programme (WFP)

An international programme that works with a range of agencies, organisations and charities to supply food to countries/places that are suffering significant shortages.  The WFP assists in emergency situations after natural disasters and conflict such as the Haiti earthquake that have destroyed crops, stores of food and infrastructure for the usual distribution of food.  It also helps with more structural problems such as Zimbabwe where political problems and farm ownership conflicts have vastly reduced the production of food in the country.

A more positive aspect of the impact of food shortages has been the development of technology and farming techniques to vastly increase the productivity of land and farms. Synthetic fertilisers have greatly increased nitrate contents in soils enabling much improved yields.  Mechanisation and the falling cost of machinery have reduced the labour requirements in farming and allow large areas to be ploughed and harvested in a much shorter time.

The Green Revolution

It started in the 1960s and increased the supply of food substantially especially in India and Mexico.  Crop yields were significantly through several methods:

  • Development of seed varieties (cereals/rice) that produced much higher yields and were more resistant to drought & disease.
  • Increased use of pesticides, fertilisers and irrigation to improve yields of crops.
  • Increased mechanisation of agriculture.

Criticisms: higher costs (new seeds needed each year, more capital intensive), mechanisation causes rural unemployment.

Test Yourself

Grab a pen and start improving your exam technique

1) Define pastoral farming. [1 mark]

2) Describe the differences in inputs and outputs of subsistence  and commercial farming. [5 marks]

3) Explain using examples why intensive farming has high capital inputs. [5 marks]

4) Describe 3 ways in which modern farming techniques have increased the supply of food. [ 3 x 2 marks]

5) Farming techniques have been blamed for environmental damage such as soil degradation, drought and flooding.  With reference to examples you have studied explain how farming can damage the environment. [7 marks]