As the global population grows, so does the need for greater agricultural output – that is, the more people there are on earth, the more food we need to grow to keep everyone alive. At the same time, agriculture and the climate crisis are so interrelated, there have been calls for radical overhauls of the current farming practices to address the deteriorating climate. These competing needs converge most obviously in the phenomenon of over-cultivation, so let’s take a closer look.
What is over-cultivation?
When crops are grown on farmland too many times without a break, the ongoing agriculture depletes the soil’s nutrients and degrades the overall health and fertility of the soil. This leads to soil sterilisation, whereby the soil can become incapable of growing anything at all. Over-cultivation has currently affected about one-third of the total global land dedicated to farming, which is estimated to be around 10 million hectares of land annually.
What causes over-cultivation?
To an extent, most of the environmental problems we see today stem from overpopulation. Due to improvements in global healthcare, there is a constant increase in birth rates alongside increasing life expectancy. This has resulted in population growth that is not quite equal to Earth’s natural resources – meaning that there are more people than the earth can provide for. Naturally, the increase in population causes a rise in the demand for food, which pressures farmers into taking measures that gradually lead to over-cultivation.
With growing populations, farmers are pushed to use more and more fertilisers and pesticides to yield enough produce to meet demand. When overused, the soil becomes saturated with fertiliser, damaging the soil structure and, paradoxically, reducing rather than improving the fertility of the soil.
Moreover, as the need for residential and commercial land use grows, farmers are left with very limited areas of land for agriculture. This leads them to run two-to-three times more cycles of cultivation on the same piece of land in order to meet demands. These repetitive cycles in turn cause the land quality, fertility, and soil health to deteriorate.
What are the negative effects of over-cultivation?
As discussed above, over-cultivation can permanently damage the productivity and fertility of the land. This can result in desertification, which brings its own set of problems (drought conditions being the most prominent).
Furthermore, when farmland becomes infertile, farmers are pressured to expand and convert the surrounding forests into agricultural land to supply enough food. The resulting deforestation causes soil erosion, soil fertility reduction, and larger-scale issues, like accelerated global warming and famine.
How can we reverse the effects of over-cultivation?
The best way to address the consequences of over-cultivation is by implementing sustainable agricultural methods. A major change that farmers can implement is crop rotation, a system where farmers grow a different crop each year on the same land. This provides a period of healing for the soil: as different crops use different nutrients, the soil can regenerate year by year. Moreover, farmers can have fallow periods, where land is left unsown and allowed to rest altogether in between crop rotations.
In order to minimise soil erosion and prevent excessive loss of water, farmers should consider the slope and shape of the land when ploughing. This way they will be ploughing with the contours of the land and not against it.
Moreover, reforestation should be encouraged. Trees not only prevent soil erosion but also assist in returning land to its natural state by conserving nutrients. Tree roots can also hold the soil together and encourage soil health by promoting plant-bacteria interactions.
The Agricultural Situation in Australia
In 2020, it was reported that the state of New South Wales lost 60,800 hectares of woody vegetation in 2018 and more than half was for agriculture. According to government data, 55% of Australian land (427 million hectares) is used for agriculture. As a result of farming development and practices, the government has also listed ten ecological communities as endangered or critically endangered, making it clear that over-cultivation is also a major environmental problem in Australia.
Although there are laws, movements, and projects like the Yarra Yarra Biodiversity Corridor (which focuses on the reforestation of non-viable farmland with indigenous plant species), there is still a long way to go. This is a critical time to understand how we can reform our agriculture and food systems in order to make them more sustainable and fight against climate change, not only in Australia, but across the world. We hope that the agricultural sector can adapt their practices so we can grow enough food while preserving our environment!
If you liked this article, you might like to learn about vertical farming.
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