In our last four posts, we explored the consequences agricultural pollution can have on the environment. But the ultimate goal of educating people on the harmful impacts of pollutants is to inspire them to take action to prevent and mitigate these issues with consistent efforts. Today, I present some agriculture-related tips provided by government agencies from various countries, to guide farm owners on how to reduce the negative impacts of farming.
Since most of us should be aware of the benefits of not relying on synthetic fertilisers containing nitrogen, phosphorus and other harmful chemicals, the discussion posts in this category will focus on some of the lesser-known tips for farmers, which have not been covered extensively in the module’s lectures. So here’s today’s focus: are cover and perennial crops our best friends?
Tip: Cover and perennial crops are your best friends!
Benefits: Reduces nonpoint source pollution such as soil erosion (and hence sedimentation in nearby waters) (United States Environmental Protection Agency, 2020).
Limitations: Suitability of crops? Demand for these varieties? What about vegetables?
Perennial crops, with their extensive root systems, are extremely efficient in preventing topsoil erosion (Cox et al., 2006, p. 649). Examples of these include:
- tree fruits (e.g. apple, pear, citrus, persimmon)
- tree nuts (e.g. almond, walnut, chestnut)
- berries (e.g. grape, blueberry, raspberry)
- a small number of vegetables such as asparagus and tomato
- specially developed perennial varieties of grains
As these crops do not require seasonal replanting and a lot of maintenance, they are capable of resulting in minimal disturbance to the soil, hence ensuring its stability. This also means that in the event of heavy rain or excess irrigation, less soil particles containing toxic chemicals are likely to enter the nearby waterways. Cover crops, which are planted to cover and protect the soil, also serve a similar purpose.
However, as some of you may have realised, this solution works better for farms which specialise in growing fruits and nuts. This is due to the fact that few varieties of vegetables are perennial in nature. Although some root crops (e.g. ginger, potatoes) may be classified as perennial, the act of digging them out of the ground during harvest brings more questions on whether it defeats the purpose of planting them to minimise soil disturbance.
I believe that the effectiveness of this solution will also depend heavily on the tastes and preferences of the farms’ target customers. In addition, farmers may also need to consider whether a certain type of perennial crop is suited for the types of soil they have in their farms.
At the same time, another pressing concern from farmers is whether these perennial varieties are capable of meeting the world’s growing demand for food. Annual crops, on the contrary, often have high yields which are crucial to developing countries which struggle to meet their projected food demand (Food and Agriculture Organisation of the United Nations, 2014, p.8).
Overall, although the cultivation of cover and perennial crops may be effective in reducing the levels of sedimentation and chemical pollution in nearby water sources, farmers will have to ensure that this practice is economically sustainable for their livelihoods before making any changes to their operations.
Please feel free to discuss any thoughts you have on this topic!
Yours,
Jialing
Reference List
Cox, T.S., Glover, J.D., Van Tassel, D.L., Cox, C.M. and DeHaan, L.R. (2006) Prospects for Developing Perennial Grain Crops, BioScience, 56(8), pp. 649-659. doi: 10.1641/0006-3568(2006)56[649:pfdpgc]2.0.co;2.
Food and Agriculture Organisation of the United Nations (2014) Perennial Crops for Food Security: Proceedings of the FAO Expert Workshop. Available at: http://www.fao.org/3/a-i3495e.pdf (Accessed: 24 September 2020).
United States Environmental Protection Agency (2020) The Sources and Solutions: Agriculture. Available at: https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture (Accessed: 24 September 2020).