261 – Agricultural water pollution
Agriculture is a major source of pollution in many rivers, lakes and coastal waters. The problems are nutrients, mainly nitrogen (N) and phosphorus (P), and sediment, causing eutrophication and turbidity.
I’ve been involved in various pieces of economic analysis looking at possible strategies to reduce these problems, including work on the Gippsland Lakes in eastern Victoria, rivers in central Victoria, Lake Karapiro in New Zealand and currently the Great Barrier Reef.
What have we learnt?
Firstly, reducing pollution to low levels can be very expensive. Even if the cost is moderate per hectare of agricultural land, it adds up if changes are needed over large areas, as they often are. For example, we estimated that it would cost at least a billion dollars over 25 years to reduce phosphorus flows into the Gippsland lakes by 40 per cent (Roberts et al., 2012).
Secondly, there is a lot of heterogeneity in the cost of reducing pollution. There is heterogeneity between the costs of different methods of pollution reduction, and heterogeneity in the cost of some methods in different parts of the catchment.
This means that it can really pay off to have a system or a policy that targets pollution reduction to the cheapest options in the cheapest places (‘cheapest’ meaning best bang for the buck, not just lowest cost irrespective of effectiveness). If a policy doesn’t account well for cost heterogeneity, it will achieve much less pollution reduction than it potentially could for a given budget.
There is a tendency for the most cost-effective interventions to be relatively close to the water body, rather than further away. This is not always true, but it is a trend.
Next, we generally observe increasing marginal costs as the pollution reduction target gets more ambitious. Small reductions can often be achieved quite cheaply, but costs increase at an increasing rate as the pollution-reduction target goes up.
Life gets even more complicated if you are trying to manage more than one pollutant at a time. For example, Doole et al. (2013) looked at strategies to reduce both phosphorus and sediment. The two are somewhat correlated, but even so, if you just targeted sediment reductions, you probably wouldn’t achieve worthwhile reductions in P. This is partly because, in the region we studied, it’s much cheaper to reduce sediment than phosphorus.
Also, the most cost-effective strategy to reduce P is different from the most cost-effect strategy for sediment, so it’s important to understand the relative importance of the two pollutants (or three, in some cases).
The challenge for environmental managers is how to factor these insights into the planning of their strategies. The environmental benefits of doing so can be really substantial, compared with designing strategies on the basis of biological and physical considerations only, although that is quite common in practice (i.e. just focusing on biology and ignoring the economics). What’s required is systematic analysis that also factors in project costs (including maintenance costs and compliance costs) and likely farmer behaviour in response to the policy or project.
The work we did on the Gippsland Lakes is a good example of an approach that is reasonably simple (it’s spreadsheet-based) but comprehensive enough to do a good job.
Further reading
Doole, G., Vigiak, O., Roberts, A.M. and Pannell, D.J. (2013). Cost-effective strategies to mitigate multiple pollutants in an agricultural catchment in North-Central Victoria, Australia. Australian Journal of Agricultural and Resource Economics 57(3), 441-460. Journal web site ◊ IDEAS page
Doole, G. and Pannell, D.J. (2012). Empirical evaluation of nonpoint pollution policies under agent heterogeneity: regulating intensive dairy production in the Waikato region of New Zealand, Australian Journal of Agricultural and Resource Economics 56(1), 82-101. Journal web site ◊ IDEAS page
Roberts, A.M. Pannell, D.J. Doole, G. and Vigiak, O. (2012). Agricultural land management strategies to reduce phosphorus loads in the Gippsland Lakes, Australia, Agricultural Systems 106(1), 11-22. Journal web site ◊ IDEAS page
Prof. Pannell i really enjoyed this topic, i don´t know if trough your research you can use some geochemical tools for correlation the polutants behavior at that area. Maybe this could be and additional clue for decide best strategies to reduce problems, think in other locations and why not rebuild your results.
Prof.Dave,I really thank you for that topic.In my village remote Kenya more is happening in water pollution in the rivers and dams. Sometimes it happens when the small holder farmer is not aware of the social cost.I really wonder who will come to the rescue of the innocent who do not even understand what is water pollution.Thanks once more for taking me through that educative part.
Thank you for saying it out Margaret,I always see it on the news , but I would like to advise you to stand out from that dust,find a way to speak out…form a project that teaches them/us how to Not pollute our rivers and lakes etc.
Be a today’s hero
Thank you once again…
I am from Kenya too!I can quite relate
Prof.Dave, thanks for the well presented scenario of the situation on the agriculture practices effects in relation to water quality. Along the Barrier Reef in Australia for example, I know some various efforts to reduce diffuse impacts have been implemented, however knowing the value of the Reef as World Heritage site I may find so obvious that government is supporting the initiative. How is other sites i.e. Gippsland lakes and other like in New Zealand? Do you see the same zeal from the government support (willingness)?. Are there some positive results from Australian government efforts to control upstream diffuse sources along GBR?
Your opinions can help to shad some light on the other potential sites around the world which are also commonly get pollution from upstream from diffuse sources.
The efforts with the GBR so far have been a start, but deficient in some respects. The amount of money dedicated is much less than would be needed to achieve the target of really protecting the reef. The way the money has been spent has not been sufficiently well targeted or sufficiently based on holistic analysis. There have been some improvements in the latter recently (my team has been involved), but further improvements needed.
The Gippsland Lakes have not been nearly as well supported (financially) as they need. New Zealand is generally doing a much better job with its policies and initiatives to reduce water pollution than Australia.
Good governing policies and strategies will guide and pave the way forward to overcome the key challenges facing agriculture sector.
Prof Dave,
it is refreshing to read your insightful perspective on water population and the examples therein. It is very sad especially if you visit Northern part of Ghana where a lot of agriculture activities are ongoing. All dams and reservoirs have been heavily silted due to sediments from agriculture activities. Meanwhile, irrigation schemes have been constructed on lakes and rivers without any buffer zones and this is really disturbing the ecosystems around.
Sir,
I’d like to ask why is massive indoor farming as a primary means for crop production not pursued when it somehow mitigates resource scarcity and degradation? I know that the capitalis relatively big and the tech is not as fully developed as field machineries, still, dont you think that these potentially loop holed systems should receive incentives or lower social costs to encourage farmers to adopt it? It’s a farfetched vision, still, i’d like to hear your opinion about it.
The problem is just the cost. It doesn’t seem likely to be economically viable on the scale required when you look at global supply and demand.
Thank you so much for this article!
I was wondering if you could bring examples of specific economic analysis of existing projects in agriculture or any natural resources management acitivies. It is quite difficult to account for all externalities, and incorporate them into the spreadsheets to see the ERR. However this analysis is important to justify regional and global effort in pollution reduction, or climate change mitigation.
I can, though the studies tend to be behind pay walls at academic journals. Here are some that I was involved in:
Doole, G., Vigiak, O., Roberts, A.M. and Pannell, D.J. (2013). Cost-effective strategies to mitigate multiple pollutants in an agricultural catchment in North-Central Victoria, Australia, Australian Journal of Agricultural and Resource Economics 57(3), 441-460.
Roberts, A.M. Pannell, D.J. Doole, G. and Vigiak, O. (2012). Agricultural land management strategies to reduce phosphorus loads in the Gippsland Lakes, Australia, Agricultural Systems 106(1), 11-22.
Doole, G. and Pannell, D.J. (2012). Empirical evaluation of nonpoint pollution policies under agent heterogeneity: regulating intensive dairy production in the Waikato region of New Zealand, Australian Journal of Agricultural and Resource Economics 56(1), 82-101.
Doole, G., Ramilan, T. and Pannell, D.J. (2011). Framework for evaluating management interventions for water quality improvement across multiple agents, Environmental Modelling and Software 26(7), 860-872.
Thank you Sir, It’s really intresting elaborating this topic. I would also like to contribute on water quality. It is a fundamental problem on Agriculture, that cause Plants contamination. These contaminations on plants are caused by Water Irrigation. As far as am concern, I think to develope Agricultural production, we should first focus on the quality of water. Strong measures are suppose to be taken to improve the quality of water for Irrigation.
It’s really a very expensive way to reduce pollutants on water bodies.
But I would like to ask, What could we do to involve local people in this work?
I think, if we serch for other local ways to reduce pollutants on water bodies would reduce cost. I.e we do not need to use machines and other scientific methods to do the work.
Hi Dawood. I don’t know enough about the specific context you are talking about, but in general I’d say that involving local people can work if there is there is a clear benefit to them. If there isn’t you probably need a different policy approach.
This topic is really interesting. Water pollution is a major problem in India with groundwater contamination being a big issue. I would be interested to know of any cost benefit analysis has been conducted for northern agricultural regions of India which are known for indiscriminate use of pesticides.
I’m sorry but I’m not familiar with what might be available on that topic. Good luck finding what you’re looking for.
Thanks Dave for this write up. Water pollution problem has always been a major problem in my country Nigeria especially sedimentation which has resulted to shallow water ways and flooding of the water banks during the peak of the raining season. This problem is largely due to the practice of soil tillage by farmers. If this is to be checked local farmers ought to be encouraged to adopt zero tillage practice but they must be convinced the the practice is economically beneficial to them.
nice knowlege
The impact of rapid economic expansion has put significant pressure on China’s scarce freshwater sources with approximately 60 per cent of groundwater and 35 per cent of rivers polluted to levels unsuitable for direct human contact.
The government has introduced key policies in the past three years aimed at addressing the growing problem, including the Water Pollution Prevention and Control Action Plan in 2015, which is China’s most comprehensive water policy to date.
Public participation policies provide a social method in support of more traditional command and control policies, and market manipulations that have been characteristic of China’s approach to addressing water pollution.
Social media provides a networked environment to develop government approved frameworks for public participation to support established, centralised water pollution policies. This approach is tentatively being explored by the Chinese Government.
Summary
The Chinese Government has demonstrated in recent times that it is serious about its water pollution problem and has developed comprehensive policies and dedicated significant resources to address the issue. Public awareness of water pollution issues in China is growing, and despite a restrictive and controlled social media environment, there are signs that the government is increasingly willing to engage with its citizens. The character of these interactions is distinctly Chinese in that the government first organises the pathways through which its citizens can provide feedback rather than allowing independent and unrestricted social movements to emerge, which are swiftly shut down. This approach contributes to the enforcement of state policies at a citizen level, while maintaining the central and hierarchical character of Chinese political power.
Analysis
China is home to approximately 20 per cent of the world’s population, but only seven per cent of the world’s fresh water reserves. Millions of Chinese citizens regularly drink water that has been deemed unfit for human consumption as a result of the contamination of waterways, accrued from the increasing industrial pollution associated with its massive economic growth. Public exposure to the problems associated with water pollution has increased as a result of the increased rate of direct and indirect consumption and demand for water from China’s growing middle class that has emerged alongside its growing economy. This has forced China to address the drinking water quality and supply concerns of its citizens, while managing the increasing demand for water from the intensive industrial base of its economy.
The scale of the water pollution problem in China is immense, with high levels of contamination in its rivers, lakes, groundwater and oceans. According to China’s Environmental Protection Authority, 35 per cent of China’s major rivers are not fit for direct human contact, and nearly all of its drinking water requires some degree of treatment. Although 600 million urban residents and 400 million rural residents reportedly have access to clean drinking water, the quality remains unreliable and water is boiled and disinfected as a standard precaution before drinking. That still leaves approximately 300 million rural Chinese without regular access to safe drinking water. The problem transcends drinking water concerns, with 19 per cent of China’s seven rivers and basins unsuitable for agricultural or industrial use and 30 to 50 per cent of Chinese coastal fish stocks depleted from overfishing and pollution. The effects of widespread water pollution include mortality, reduced biodiversity and loss of ecosystems, and are already having an impact on the Chinese population.
Water pollution is becoming a serious problem in my country Liberia as a result of agriculture. Sedimentation and to a lesser degree nutrients are becoming major causes of the water pollution. There are thousands of small scale vegetable and other crop growers in Liberia who are mostly doing shifting cultivation. This has resulted to the exposure of the surface areas thousand of acres of land to weathering and erosion – sedimentation. Although at minimum level, these farmers also use agro-chemicals including fertilization, pesticide and herbicide. In Liberia NPK 15-15-15 is the widely used brand of fertilizer use; and as the cultivation areas increases so does the use of these chemical.
Currently there is very little known action being taken by Government in Liberia to create awareness about the problem and to begin proactive engagement with farming communities to mitigate these problem.
Agriculture and water problem is becoming a serious problem in some parts of Nepal where crops are grown commercially. However, water pollution problem is not well researched and understood in case of Nepal.
Prof Dave , Thanks for this research, indeed there is need for policies that can be economically feasible , farmers and other humanitarian actors should be sensitize on the policies, means of verification, monitoring mechanism should be put in place to see to it that the policy is implemented.
Water pollution is a major problem world wide and costly to manage, therefore it is imperative that governments at policy level should raise farmers awareness that if farmers achieve reduction in water pollution that will invariably make more resources available to them for increase production. Farmers are mostly concern about production costs for profitability and has no regards for social costs.
With growing population and pressure on agriculture to produce more with less water and fertilizers, if there was ever an appropriate time to say that we need to adapt the use of technology its right about now.The long and short of it technology can help us to gather data and analyse the soil and determine where we can apply fertilizer and water in proportion to what is in the soil. it will reduce the use of fertilizer and increase production.
Thank u sir for this wtite up…. lack of irrigation facilities and under ground water is becoming a major issue in my country India… so farmers are compell to do dry crops cultivations and it makes them more trouble due to higher input cost than output price….
Insightful. Great, indepth work by Pannell D.J, et all. The quest by man to produce enhanced agricultural products, using various nutrients, come at both social and environmental costs. The long term solution might lie with agricultural scientists developing more environmental friendly agricultural inputs, in term of nutrients.
Great work. Insightful. Water pollution resulting from agricultural activities is real. The long term solution might lie with agricultural scientists developing more environmental friendly agricultural inputs, in terms of , nutrients.
Policies should be strengthened against water pollution control
On my side, Globally we need to take into account water pollution in our counties to make agriculture sustainable. Currently many countries don’t take account this serious issue, some measures have to be taken.
Thank you for this great article sir. well in my country, Kenya most of the farmers are located in the rural areas which lack proper communication channels to keep them informed of the causes and consequences of water pollution hence they continue using large quantities of chemical fertilizers rich in Nitrogen and Phosphorus thus increasing cases of water pollution as years go by.
I also think poor government policies in matters water pollution have played a big role in this.
Yes! the reduction of water pollution is location-based and all countries should be responsible for its waterbodies; i think there should be a policy for this and defaulters should be fined especially in developing countries where the leaders are non-challant.
Because it is a long period process; noone can do it all by him/herself!
Prof
Do you think the research on organic farming and agroforestry could improve the soil’s health, what if the government spent more money on R&D activities.
As the externalities created by farming could act as an impediment for themselves and the betterment of the ecosystem
There are probably relatively sustainable farming options that are more widely adoptable than those two, but more generally I do think that research has a major role to play in developing and testing more environmentally friendly farming systems.
Thank you very much sir. i enjoyed the read. i must add my little piece. In my country Nigeria, We depend more on Rain. its recently the govt started investing in irrigation. In Rural areas, lots of small farmers abuse the use of herbicides which sips into streams, erosion is a huge factor in lots of places and sedimentation. Unfortunately, Issues like this are hardly discussed or recognized over here. Ignorance is a major factor. farmers only care about maximising output to get more profit and dont care about the social cost. And the same stream which is the source of water for the crops is also the same source the farmers drink water from. The first steps to tackling this is mass education, Govt policies that ensure farmers bear some form of responsibility. the solution lies in the little things done to prevent or reduce rather water pollution rather than fixing it {which is always costly and sometimes almost impossible}
La lecture était très intéressante. Merci pour la connaissance de plus.
The long term solution might lie with agricultural scientists developing more environmental friendly agricultural inputs, in terms of , nutrients.
Like the lecture concluded it would be quite expensive to manage. Here in Nigeria the use of chemicals have made large profits for farmers which is usually short term. They make a reasonable income however most farmers are not aware of the implications and even if they were they are least interested in the effects. They only live for today. In the long run I see a situation where farmers make large output but have very minimal patronage because their customers wouldn’t be able to purchase goods anymore because of bad health. This is the time I believe African government and NGO must be aggressive with this information.
Thank you very much Pro David, It”s a well known fact that both farmers and government are just after what they can gain at the moment without future benefits or continuity, we lack planning, not until catastrophe happens just like the recent flood (2022) that came all the way from Cameroon to Nigeria and move round from North to East and West. This could have been prevented, If adequate planning had been made before then, many lives and property were lost. This is an external cost which supposed to have been taking care of by the government. With this we are sure lots of water pollution was the order of the day as well as erosion of many farms which resulted to food scarcity and high cost of food.
I think they way we use phosphorus in agriculture and the way we manage in byproduct that contain phosphorus can help us reduce the phosphorus in the environment. Phosphorus and sediment have a relative, but I think agriculture activities is using a lot of phosphorus in growing food. I hope the smart fertilizer, or intensive study in applying phosphorus for growing plant can help the farmer not over-dosage of not only phosphorus but also other fertilizers. Besides, the manure of the dairy and poultry also discharge phosphorus in the environment. Well-utilized that byproduct source can help us save money and protect the environment. I would like to try it in my PhD project to see how my idea works.
Dear Colleagues.
Looking pollution in a holistic angle, but within the agricultural production and value chain, indeed, chemical pollution mainly (Nitrogen and Phosphorous) and sedimentation having being highlighted as the major agricultural elements of pollution, we must remember that, other activities like PHH including seed/grain bulking and storage involves the use of plastic bags for both packing and storage, which if burnt, like others do as a means of eradicating waste disposal, produces harmful gases like Sulphur dioxide, Nitrogen Oxide, in addition to causing sedimentation and blocking water infiltration into the soil after when poorly disposed. All these are harmful to both human and animal health.