Agriculture

Agriculture is an ancient art mastered over thousands of years of trial and error. With growing human populations, there needed to be a way to supply the global demand for food, and farming was the answer. In recent centuries agriculture has come on leaps and bounds from its humble beginnings, technological and chemical advances have revolutionised the way we farm our livestock and crops. Today we shall be going the effect of agriculture on biodiversity and some of the ways agriculture has improved and needs to continue to improve to become more sustainable.

Agriculture and its effect on biodiversity

Farmers use only certain species to maximise efficiency and output of produce, which often leads to a limited genes pool (the abundance and variation of genes in a population), meaning that the farm animals and crops are susceptible to disease. Monocultures are often created to protect the wanted crops from foreign species.

Farmlands are harmful to species diversity in the surrounding area in the following ways:

• Pesticides kill any unwanted crops, and pests on the desirable crops can thrive. This rapidly reduces the biodiversity in the surrounding area and the gene pool of all the crops in the field.
• Overgrazing of land (normally by cattle and sheep) leads to the destruction of certain sepcies’ habitats which will often not grow back. The soil is often exposed and can be eroded by harsh winds and rainfall.
• Removal of trees, shrubs, stumps, hedgerows (a strip of dense shrubbery that acts as a natural fence), and the draining of ponds and marshes also removes the homes for many species and ecosystems.
• Minimal use of intercropping (planting different species in the spaces between rows of crops) and crop rotation (planting different species alternately in the same field) leads to lessened biodiversity.
• The use of fertilisers can lead to eutrophication in nearby rivers and lakes.
• Minimal use of intercropping (planting different species in the spaces between rows of crops) and crop rotation (planting different species alternately in the same field) leads to lessened biodiversity.
• The release of effluent (liquid waste) into nearby bodies of water can be harmful to the wildlife that lives there and can also decrease soil quality.

Conservation of biodiversity in agriculture

There are methods that farmers can employ to minimise agriculture-related biodiversity loss on their land.

The methods include:

• The practice of intercropping, undersowing (planting a crop that will start growing as soon as the crop the farmers are interested in has been harvested), and crop rotation to increase the genetic diversity in the crop fields.

• Pest management strategies different from pesticides can be used, such as introducing the natural enemy to the pest in the field.

• Refraining from draining boggy sections of the field or leaving some marshy sections for the various species that thrive here.

• Preserve hedgerows in between fields rather than erecting fences.

• Only cut field edges once seed dispersal has occurred.

• Introduce areas where the use of pesticides is limited so that wild plants and animals can breed.

Fig. 1 - Soil in monoculture vs crop rotation

Advantages of conservational methods

• Increased crop yield in the long term as increased biodiversity in the field will increase the gene pool available to the crops, meaning that they are less susceptible to disease.
• Through crop rotation and intercropping, soil quality will increase because of the wide range of nutrients it receives.
• Without burning fossil fuels, the pollution resulting from industrial farming methods decreases.

Sustainable agriculture

Sustainable agriculture aims to implement methods of growing crops and livestock that are reproducible in the long term while also having minimal effect on the environment. This is done by considering the global need for food production and the consequences of agriculture and global warming.

Goals associated with sustainable agriculture are the promotion of biodiversity in wildlife and crops, conserving freshwater, and reducing chemical pesticide and fertiliser use. Common farming strategies employed to achieve sustainable agriculture include:

• Natural fertilisers - plants that produce the nutrients that they or other plants around them require can be extremely useful in reducing fertiliser use.

• Crop rotation - mixing crops and crop rotation can help reduce pesticides as the pests will not grow accustomed to the crops in this area.

• Natural pesticides - crops that exhibit defences that kill certain pests can be introduced to help other regularly attacked plants.

• Renewable energy sources - the use of renewable energy sources in agriculture reduces the need for burning fossil fuels, which is a huge factor impacting global warming.

Agricultural occupancy condition

An agricultural occupancy condition is a law that limits who can occupy land in the countryside so that the maximum possible space can be used for agricultural purposes. It usually requires that the person living in the particular settlement is either working or retired from working in agricultural practices in the local area. Often called an agricultural tie, they were introduced to allow farmers to easily build houses on their land without being opposed.

Regenerative agriculture

Regenerative agriculture is a practice used by farmers that focuses on soil health while also monitoring water management and fertiliser use. This is done in the following ways:

• By using crop rotation and intercropping, farmers can increase plant diversity and improve the health of the soil. Different plants release varying types and amounts of carbohydrates into the soil, broken down by microbes that return many nutrients to the plant and the soil. If the soil only receives certain carbohydrates for an extended period, it can suffer if it requires some absent carbohydrates.
• Bare soil will erode over time, so farmers can use the technique of cover cropping (planting crops that cover the soil and won’t necessarily be harvested) so that the soil is protected and receives all the necessary nutrients and organic matter.

• By minimising till practices, farmers can reduce physical disturbance to the soil, reducing the loss of organic matter or soil microbes and other species.

  Tillage refers to soil preparation on farms by mechanical agitation such as digging, overturning, and stirring.

• Overapplication and misuse of fertilisers and pesticides can be detrimental to soil health, so most farmers usually refrain from this.

Agricultural engineering

Farmers can often produce a more desirable result from their crops or animals using genetic engineering. Genetic engineering involves the removal of the desired gene from one organism and the insertion of this gene into the target organism. This is an intentional modification of the characteristics of a plant or an animal. The introduced gene typically ensures that the organism grows faster, bigger or has a characteristic not normally present in its species.

There are ethical concerns around genetically modifying animals, but livestock is still widely genetically engineered to make animals grow faster or have a higher fat to muscle ratio. Crops are more regularly engineered, often increasing their resistance to pests, making them grow larger or faster, or increasing their vitamin content.

Agricultural revolution

The (British) agricultural revolution concerns the changes that began to occur in Britain that only really concluded towards the start of the 19th century. This included many technical improvements to the traditional methods of farming. Some of these technical improvements were:

• Modern, more efficient machinery. For example, tractors, dragged teeth (called shanks) that pierce the soil, and rotatory motion of disks and teeth.

• New techniques of farming to increase yield, such as intercropping and under sowing.

• Better drainage, often by the installation of subsurface drainage pipes.

• Scientific methods of breeding, such as the previously mentioned breeding, promote beta-carotene levels.

• Smarter water management. This can be done by improving irrigation systems and climate-smart farming methods.

• Steam engine ploughs could plough ten times faster than a plough dragged by horses.

Fig. 2 - Traditional vs modern agriculture

Agriculture - Key takeaways