Fertilisers

#16: EU Directives on Nitrates and Pesticides

Welcome back everyone! The future of agricultural pollution is not all bleak as there are measures put in place to allow the environment to gradually revert back to a time where there was less pollution. In this post, we aim to summarise some of the directives and legislations that the EU has implemented, especially against the use of excess pesticides and nitrates in fertilisers.

The use of pesticides in agriculture can help to fight crop pests, therefore increasing quality and yield of the crop. However, in the past few decades, it is realised that pesticide overuse can lead to serious health and environmental impacts. Therefore, the EU Common Agricultural Policy (CAP) was introduced in 1962, which implements a series of agricultural subsidies and programmes that has been revised and revamped throughout the years. Embedded within the CAP, there are some policies that not only target the use of pesticides, but also promote the sustainable use of plant protection.

Here are some of the policies and measures stated within the CAP:

  • Direct payments are not given to farmers who can generate the highest yield, this minimises the need for farm owners to use excess pesticides just to garner greater yield
  • “Green” direct payments are disbursed to farm owners who adopt farming practices that help take a step towards achieving environmental and climate goals
  • Cross-compliance rules state that farm owners will receive a cut from their payments if they do not adhere to the EU laws associated to environment, climate change, good agricultural condition of land, human, animal and plant health standards and animal welfare
  • These cross-compliance rules include conditions for use of pesticides, especially with regards to fruits and vegetables, where a minimum 10% of spending in operational programmes must go towards environmental actions
  • Agri-environmental measures are geared towards minimising the risks of environmental degradation and improve the sustainability of agro-ecosystems

It is the responsibility of the farm advisory systems to alert farm owners about conditions under cross-compliance, green direct payments, water framework directive and the directive on sustainable pesticide use. With regards to organic farming, chemical pesticides, synthetic fertilisers, antibiotics and other substances are severely prohibited.

A summary of the EU Nitrates Directive

The use of inorganic nitrogen and phosphorus fertilisers to supply the crops with nutrients to grow quickly and in abundance helps to boost crop yield. However, it is not sustainable as they stimulate eutrophication upon reaching water bodies. Therefore, the EU’s Nitrates Directive was introduced in 1991. The directive aims to achieve reduction in water pollution by nitrates from agricultural sources and to promoting good farming practices.

This directive is enforced by the EU countries. These countries would need to ensure that agricultural water quality is regularly inspected, demarcate areas which could become heavily contaminated by nitrates once applied, as well as establish acts of good agricultural practices. With regards to the areas easily contaminated by nitrates, the directive restricts up to 170kg as the maximum annual limit of nitrogen from livestock manure (used as fertilisers) that can be applied per hectare. Acts of good agricultural practice include adhering to fertiliser application periods, fertiliser application areas, manure storage methods, manure spreading methods as well as certain land management measures. Every 4 years, member states are required to report on the nitrates concentrations in waters, presence of eutrophication, any revisions in the areas vulnerable to nitrate pollution as well as future trends in water quality.

At present, as with many other solutions or legislations implemented to curb pollution stemming from agriculture, there are limitations which hamper its environmental success. It is worthy to note that studies mention a hiccup in its intended success is due to a lack of governance-oriented debate. Only with this debate, the knowledge of the policy and directive performances can then be fully understood. To overcome this limitation, it is encouraged that member states be required to provide to EU Commission a thorough assessment of the governance dynamics that reinforce the policy and directive implementation, along with the 4-yearly environmental monitoring report.

References:

Musacchio, A., Re, V., Mas-Pla, J. and Sacchi, E., 2019. EU Nitrates Directive, from theory to practice: Environmental effectiveness and influence of regional governance on its performance. Ambio, 49(2), pp.504-516.

European Commission – European Commission. 2020. Pesticides In Agriculture. [online] Available at: <https://ec.europa.eu/info/food-farming-fisheries/sustainability/environmental-sustainability/low-input-farming/pesticides_en> [Accessed 24 July 2020].

European Commission – European Commission. 2020. Nitrates. [online] Available at: <https://ec.europa.eu/info/food-farming-fisheries/sustainability/environmental-sustainability/low-input-farming/nitrates_en> [Accessed 24 July 2020].

Ec.europa.eu. 2020. Nitrates – Water Pollution – Environment – European Commission. [online] Available at: <https://ec.europa.eu/environment/water/water-nitrates/index_en.html> [Accessed 24 July 2020].

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#15: Buffer Zones along Farm Boundaries

In many of the previous posts, there is a lot that is mentioned regarding water pollution as a result of intensified agriculture. This post will be focussed on a possible solution that could minimise the risk of water pollution.

One approach to solving the water pollution problem is the creation of buffer zones between the polluting farms and receiving waters. A buffer zone refers to a permanently vegetated area of land which is roughly 5-100m in width, preferably placed adjacent to a watercourse. The buffer zone works by providing a biochemical and physical barrier between the pollution source and the receiving water body.

The working mechanism of the buffer zone is relatively simple. The buffer zone spreads and separates the incoming flow of pollutants, minimising its fluid velocity. This increases infiltration and subsequently reduces the water depth on the surface. Huge particles fall to the bottom as sediments while suspended particles get filtered through leaf litter and soil. The remaining pollutants get trapped in the soil of the buffer zone, which allows for decay and subsequent absorption by plant roots or adsorption onto soil particles. The removal of pollutants transported in particulate form varies according to the buffer zone’s capacity of reducing energy of the incoming flow to allow pollutant particle settling. On the contrary, the removal of pollutants transported in dissolved form depends on the ability of the buffer zone to stall the runoff long enough to facilitate the pollutants breaking down, for subsequent absorption by plants.

The effectiveness of a buffer zone is determined by a number of factors. We must consider its physical structure, the type of pollutants it must handle and the closeness of the buffer zone to the pollution source. As for agricultural catchments, they are usually located in areas of low slope where the uplands were already cleared without any buffer. Such runoff from the uplands gets channelled away in the upper catchment and could flow out of the catchment without passing through the buffer downstream. This results in a huge loss of nutrients, which in this case are pollutants, that ultimately enters water bodies and causes water pollution.

In order to ensure the effectiveness of buffering for agricultural catchments, the buffer zones should ideally extend along tributary streams, so that none of the polluting sources will be left out and allowed to channel away. Hence, all polluting sources have to pass through buffer zones to trap the pollutants, as represented in the figure below.

Ideal agricultural catchment buffer zone

Regarding the effectiveness of buffer zones towards pesticides in agriculture, it has shown commendable results. In a study conducted by Asmussen et al. (1997), it was reported that herbicide 2,4-D were reduced along a buffer zone by 77% and 69% in wet and dry conditions. In a similar study by Rohde et al. (1980), there was evidence of trifluralin loss of 96% and 86% in wet and dry conditions. The large reduction of pesticide loss can be attributed to water infiltration, sediment deposition and attachment on vegetative and organic matter.

References:

Muscutt, A., Harris, G., Bailey, S. and Davies, D., 1993. Buffer zones to improve water quality: a review of their potential use in UK agriculture. Agriculture, Ecosystems & Environment, 45(1-2), pp.59-77.

Norris, V., 1993. The use of buffer zones to protect water quality: A review. Water Resources Management, 7(4), pp.257-272.

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#9: Smart Fertilisers

Today I came across an interesting article, where I found that fertilisers could be programmed to be smart too!

Since more fertiliser applied would increase crop yield, but the more fertiliser applied, the more gets ends up the the watershed, triggering algae growth.

Hence, to prevent that from happening, there are slow-release fertilisers that has been manufactured and sold for quite some time. These fertiliser formulation acts like a capsule, containing nitrogen, phosphorus and various nutrients. The outer shell can slow the rate of entry of water to the capsule as well as the rate which end products can escape from the capsule. Nutrients are allowed to enter the soil gradually for optimal absorption. Besides that, usage is inexpensive as well as convenient.

Plantacote slow release fertiliser

Schematic diagram showing slow release of fertiliser

More recently, there is the creation of controlled release fertilisers. The shells of the capsules are tuned to only release nutrients at your desired constant rate when the a certain trigger point is hit. Such triggers could be soil temperature, pH or moisture levels.

However, there are some minor drawbacks regarding its usage. In countries with 4 seasons, when the temperature gets too warm or too cold, this might trigger the increased or decreased release of fertiliser into the soil, causing either a root burn or nutrient deficiency respectively. It is also important to note that varying amounts of nutrients is required for optimal plant growth at their different stages. Since the release of fertiliser is fairly constant during constant temperatures, an incorrect amount of nutrients would have been supplied to the plant constantly.

If these fertilisers can be modified to correct its limitations, it is definitely worth it to switch over to smart fertilisers to protect our environment (:

References:

Carbeck, J., 2019. Smarter Fertilizers Can Reduce Environmental Contamination. [online] Scientific American. Available at: <https://www.scientificamerican.com/article/smarter-fertilizers-can-reduce-environmental-contamination/> [Accessed 14 July 2020].

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#1: Fertilisers… oh fertilisers…

Hello everyone, welcome to our blog and our very first post! As the title goes, an obvious hint about the topic of this post would be about fertilisers!

Agricultural farming has been around for ages. With the advancement in technology, humans have found new efficient and effective ways to grow plantations to produce goods to feed the entire world. And with the growing demand for food quality and stock, it is inevitable that humans would look forth to find ways to improve the growth of our food. And here’s where our handy dandy fertilisers come in!

 

 

 

 

 

So, what actually does fertilisers contain? Let’s take a common fertiliser, urea, for example. Urea, like many other fertilisers, is a nitrogenous fertiliser that we apply into our agricultural fields and plantations. Simply put, it is really harmful for humans to ingest high amounts of nitrogen compounds (10 – 45 and above mg/l). Researchers have shown that too much nitrogen levels in our drinking waters could potentially be considered to be carcinogenic and a causative factor for “blue” babies. (Who knew not only should we avoid unhealthy burnt food; we need to avoid high nitrogen concentration drinking water!) “Blue” baby is a terrifying defect that happens to pregnant women who ingest high nitrogen concentration water. The result could potentially be their babies forming malfunctioned hearts resulting in low oxygen circulation, turning them blue.

There are of course standard guidelines for drinking water emplaced by WHO to abide by (I will leave the reference link below). With the high amounts of fertilisers that is required in our farming nowadays, it is truly worrisome to think about the possible agricultural run-offs due to rain or watering of plantations that end up into our groundwaters. This is especially so that we have scarce water resources (only 0.62% of water on Earth is available) and groundwater is one of our water sources that require the least amount of cleaning. However, when these nitrogen compounds are too high that it goes beyond WHO standards, removal is required using advanced technology and it is really very expensive even for developed countries to afford!

If you think about it, we produce our food to poison our limited scarce water resources. What an irony that we are harming ourselves for our own demands for food! But with that being said, is it possible we can find a way to grow our food efficiently and effectively without slowly poisoning ourselves? Perhaps we will leave that to another blog post! For now, take care and stay safe folks! 😊

References:

Agrawal, G., Lunkad, S. and Malkhed, T., 1999. Diffuse agricultural nitrate pollution of groundwaters in India. Water Science and Technology, [online] 39(3), pp.67-75. Available at: <https://iwaponline.com/wst/article-pdf/39/3/67/36089/67.pdf> [Accessed 25 June 2020].

  1. Rolling Revision Of WHO Guidelines For Drinking-Water Quality. Geneva: World Health Organization.

Picture referenced from:

  1. [image] Available at: <https://www.swiss-singapore.com/knowledge-hub/changing-dynamics-of-urea-trade-in-the-fertiliser-sector/> [Accessed 25 June 2020].
  2. [image] Available at: <https://www.indiamart.com/proddetail/urea-fertilizer-bags-14322681162.html> [Accessed 25 June 2020].
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