Having covered briefly last post about how livestock causes both land and water pollution in terms of acid deposition, today we would like to go more in-depth on livestock-induced land pollution itself.

Livestock production is also of concern when it comes to the land pollution that it causes, particularly land degradation.

Soil Erosion

Firstly, livestock production often results in the overgrazing of land and thus soil and sediment erosion (Fig.1). Soil erosion happens when pastures are exposed to extensive period of grazing without giving it enough time to recover. As increasing livestock animals roam and graze on pastures, the soil exposed can be easily carried away by wind or water. The exposed soil is therefore easily subjected to erosion. As such, soil erosion is one prolonged effect of livestock overgrazing. According to the Report of the Pew Commission on Industrial Animal Farming (PCIFAP, n.d.), animal farming is estimated to account for around 55% of soil and sediment erosion in the case of the United States, which is a rather significant number.

Fig. 1 Soil erosion in Tanzania. Obtained from: https://www.theguardian.com/environment/gallery/2017/may/04/soil-erosion-in-tanzania-in-pictures

Land Degradation and Desertification

On top of soil erosion, land degradation occurs as result of prolonged overgrazing as well (Conserve Energy Future, n.d.).  Overgrazing tends to make the soil more compact due to animal trampling, as a result reducing its ability to absorb and retain water and hence facilitating surface runoffs. This often worsens the impacts of flooding due to the low soil infiltration rate (Population Education, 2019). Whereas in other cases, soil erosion results in the loss of fertile land and thereby worsens the issue of desertification (National Geographic, 2019). In the case of Pakistan, overgrazing of pasture land is one main source of human-induced desertification, whereby more than one-third of the country is currently classified under at risk of desertification (Anjum, Wang, Xue, Saleem, Wang and Zou, 2010).

On top of that, the issue of land degradation is often further exacerbated by a lack of control over overgrazing practices, indicating a lack of timely pasture management response and land use policies.

 

 

Detective Out,

Linying

References

Anjum, S. A., Wang, L., Xue, L., Saleem, M. F., Wang, G. and Zou, C. (2010). Desertification in Pakistan: causes, impacts and management. Journal of Food, Agriculture & Environment, 8(2), 1203-1208.

Conserve Energy Future. (n.d.). What is overgrazing? Conserve Energy Future. Retrieved from: https://www.conserve-energy-future.com/causes-effects-solutions-overgrazing.php

National Geographic. (2019). Desertification, explained. National Geographic. Retrieved from: https://www.nationalgeographic.com/environment/habitats/desertification/

PCIFAP. (n.d.). Environmental impact of industrial farm animal production. Pew Commission on Industrial Farm Animal Production. Retrieved from: https://www.lclark.edu/live/files/6699-environmental-impact-of-industrial-farm-animal

Population Education. (2019). Industrialized meat production and land degradation: 3 reasons to shift to a plant-based diet. Population Education. Retrieved from: https://populationeducation.org/industrialized-meat-production-and-land-degradation-3-reasons-to-shift-to-a-plant-based-diet/#:~:text=1.,85%25%20of%20all%20soil%20erosion.&text=In%20addition%2C%20if%20too%20many,to%20the%20soil%20is%20devastating