Agricultural mechanisation

Agricultural mechanisation is the use of machinery to carry out farm work. Machines can perform tasks such as preparing land, planting crops and harvesting more quickly and with less human labour than would otherwise be needed.

For example, machinery can prepare and plant a large area in less time than people working by hand. Harvesting machinery can then collect crops quickly when they are ready. Because each operation needs less time and human labour, farming becomes more efficient.

Machines also allow farmers to work a larger area of land. This increases the scale at which crops can be grown and food produced.

Chemical fertilisers in crop production

Plants need mineral nutrients to make substances required for growth. They absorb these nutrients from the soil through their roots. If the soil does not supply enough of a needed nutrient, crop growth can be limited.

Chemical fertilisers supply mineral nutrients to farmland. Adding them can give crops access to more of the nutrients they need, helping them grow and produce more crop from the same area of land. The amount of crop produced per area of land is called the yield.

Chemical control of crop pests and weeds

Chemicals can protect crops by controlling organisms that damage the plants or interfere with their growth. Two types of chemical treatment have different targets: insecticides control insects, while herbicides control weeds.

Insecticides control insects that damage crop plants. Reducing this damage helps protect both the quality of the harvested crop and its yield, the amount produced.

Herbicides control weeds: unwanted plants growing among the crops. Weeds compete with crop plants for resources needed for growth, such as light, water and mineral ions. Controlling weeds reduces this competition, leaving more resources available to the crop.

Both treatments reduce biological causes of lost crop production, but they do so by acting on different organisms.

Selective breeding for food production

Crop plants and farm animals can differ in inherited characteristics that affect how much food they produce. For example, some crop plants produce more edible material, while some dairy cattle produce more milk.

In selective breeding, farmers choose plants or animals with a desirable inherited characteristic to be parents of the next generation. Some of their offspring inherit the characteristic. Farmers then select the most productive offspring to breed again.

By repeating this selection over many generations, the desirable characteristic becomes more common in the population. As a result, the crop or livestock can produce more food. The improvement is gradual: selecting productive parents increases the chance of productive offspring, but does not guarantee that every offspring will be equally productive.

Large-scale crop monoculture

A large-scale monoculture is the growing of one crop species over a large area. Because the plants have similar needs and are managed in similar ways, farmers can organise planting, crop management and harvesting uniformly across the field. Machinery can be used efficiently, helping to produce large quantities of food.

Disadvantages of monoculture

The same uniformity can make a crop vulnerable to pests and diseases. If a pest or disease can attack the crop species, it may spread readily because many susceptible plants grow close together across a large area.

Repeatedly growing and harvesting the crop can also deplete soil nutrients. The plants take nutrients from the soil as they grow, and some of these nutrients are removed when the crop is harvested. If they are not replaced, less may remain for future crops.

Growing one species across a large area also reduces biodiversity: there are fewer plant species in the crop area, and the uniform habitat provides fewer varied resources for other organisms.

Intensive livestock production

Intensive livestock production keeps many farm animals in a managed space to produce food such as meat, milk or eggs. Farmers control the animals’ feeding and conditions to support high production. Keeping animals close together allows large quantities of food to be produced efficiently while using less land per animal.

Consequences of high stocking density

Stocking density describes how many animals are kept in a given area. At high stocking densities, animals have frequent close contact, so disease can spread more easily between them.

Limited space can also prevent animals from carrying out normal behaviours, creating animal welfare concerns. For example, animals may have less opportunity to move around freely.

Many animals in one place produce a concentrated amount of waste. If this waste enters the surrounding environment, it can pollute land and water.