Pros & Cons Of Pesticides & Fertilizers

The use of pesticides and fertilizers in commercial and industrial agriculture has both it’s benefits and drawbacks.

In this guide, we look at what the potential list of pros and cons might be.

 

*Note – we are mainly assessing synthetic pesticides and fertilizers used in large scale agriculture in this guide. Natural pesticides and fertilizers may also have their own specific list of pros and cons

 

Summary – Pros & Cons Of Pesticides & Fertilizers

Pros

Fertilizers Help Significantly Increase Agricultural Yield

Pesticides Simultaneously Protect Agricultural Goods, Help Deliver A Higher Quality Product, & Increase Production/Yield

Can Help Use Some Resources More Sustainably

Help Meet Demand Of A Growing Population

Contribute To Economic Growth & Other Economic Benefits

 

Cons

There’s Various Ways Pesticides Might Impact Human Health

There’s Various Environmental Issues That Pesticides & Fertilizers Might Contribute To

The Use Of Fertilizer & Pesticide Has Potential Sustainable Resource Management Concerns

Pesticides & Fertilizers Can Negatively Impact Animals, Wildlife & Biodiversity

In Some Instances, Pesticides & Fertilizers May Contribute To Economic Loss

Fertilizers & Pesticides May Contribute To, Or Mask The Effects Topsoil Loss & Land Degradation

Subsidies For Pesticides Or Fertilizers May Contribute To Some Problems

Built Up Pesticide Resistance Can Compound Issues

Too Much Fertilizer Application Can Impact Soil Fertility Factors

 

Overall

Pesticide and fertilizer use has tradeoffs.

On one hand, there’s a solid argument to be made that the human population either couldn’t be fed effectively, or wouldn’t have the quality of life or scale of agricultural production without pesticides and fertilizers.

On the other hand, pesticides and fertilizers can potentially have a clear negative impact on humans, wild life, the environment, the sustainable use of resources, and other areas of society.

It might be accurate to say that the use of pesticides and fertilizers might be a crucial component of assessing whether current agricultural practices will be sustainable going into the future.

 

What Are Pesticides & Fertilizers?

Pesticides are usually a chemical or biological agent (in the case of some natural pest control methods) used to kill, repel or control a specific pest against damaging an agricultural good (such as crops or livestock) or spreading disease.

Fertilizers are usually a substance or chemical mix added to soil/land, to supply crops/plants nutrients (can be macronutrients and also micronutrients), and they can also help increase soil fertility

 

Types Of Pesticides & Fertilizers

Synthetic vs Natural

Firstly, there’s a difference between synthetic pesticides and fertilizers, and naturally derived ones.

A synthetic pesticide might be made from specific man made chemicals, where as natural pest control can involve methods like IPM.

A synthetic fertilizer can be made from fossil fuels and man made chemicals, whereas natural fertilizers might include substances or organic matter like manure, compost and food scraps, and so on.

 

Other Types

Secondly, both pesticides and fertilizers can be broken down into their individual types.

Pesticides can be broken down into the type of pest they target – insecticides, herbicides and fungicides being just a few examples (although herbicides are the most common – they make up about 80% of all pesticide use)

They can also be broken down by their chemical profile (or chemical family), or brand – glyphosate and Roundup being an example.

Fertilizers are often broken down by being a nitrogen, phosphorus, or potash fertilizer. There’s also other ways to break them down such as solid fertilizers, liquid fertilizers, slow release fertilizers, specialty fertilizers, and so on.

 

Potential Pros Of Pesticides & Fertilizers

Fertilizers Help Significantly Increase Agricultural Yield

A main function of fertilizers is to supply nutrients (macro and sometimes micro) that crops can absorb through the soil. 

This can help crops achieve more ideal growth, and usually increases yield compared to if fertilizers aren’t used.

This might especially be useful in modern times with topsoil levels being degraded in several countries due to intensive farming practices, and wind and water erosion.

Fertilizers can be used on crops that will be directly consumed by humans, but also for growth and better yields for animal feed

 

Without nitrogen fertilizers, scientists estimate that we would lose up to one third of the crops we rely on for food and other types of agriculture (kids.frontiersin.org)

 

[The use of synthetic fertilizers starting in the 19th century was] important in transforming the global food system, allowing for larger-scale industrial agriculture with large crop yields (wikipedia.org)

 

In the later half of the 20th century, increased use of nitrogen fertilizers (800% increase between 1961 and 2019) have been a crucial component of the increased productivity of conventional food systems (more than 30% per capita) (wikipedia.org)

 

Conservative estimates report 30 to 50% of crop yields are attributed to natural or synthetic commercial fertilizers (wikipedia.org)

 

Pesticides Simultaneously Protect Agricultural Goods, Help Deliver A Higher Quality Product, & Increase Production/Yield

The core function of pesticides is to target pest species to control them against damaging an agricultural good like crops.

By doing this, agricultural goods are protected (from weeds, fungi, insects, etc), they are able to maintain a higher quality for market, and there is a higher yield and productivity because more of the goods are available compared to if a certain % were damaged by pests.

They can also increase the number of times per year a crop can be grown on the same land.

 

Can Help Use Some Resources More Sustainably

Something that is not often considered is that increased yield/productivity leads to more efficient use of some resources used in agriculture.

One example of this is land – farmers can get more production/yield from the same square area of land.

 

Help Meet Demand Of A Growing Population

The world’s population has been growing in recent history.

Because fertilizers and pesticides allow for greater yield and productivity, they are a key component in being able to meet the food demand (and other agricultural product demands) of this growing population now and in the future.

 

… it has been estimated that almost half the people on the Earth are currently fed as a result of synthetic nitrogen fertilizer use (wikipedia.org)

 

Contribute To Economic Growth & Other Economic Benefits

Agriculture is one of the main industries in the world.

Increased production due to the use of fertilizers and pesticides has helped agriculture better contribute to the economy, and some of the side effects have been employment and income for society, helping farmers save money, and helping stabilize food prices.

The pesticide industry alone is estimated to be worth hundreds of billions of dollars worldwide.

One studied mentioned by wikipedia.org outlines that the health and environmental cost of pesticides in the US is offset by the increased agricultural production that pesticides provide

 

… nitrogen fertilizer use supports California’s robust agricultural economy and rural society (calag.ucanr.edu)

 

… in the U.S., farmers get an estimated fourfold return on money they spend on pesticides … [and pesticides can have a positive effect on food prices, jobs, and world hunger] (wikipedia.org)

 

Potential Cons Of Pesticides & Fertilizers

There’s Various Ways Pesticides Might Impact Human Health (Potential Toxicity)

At the farm level, farm workers and those in the near vicinity of where pesticides are used can be exposed to pesticide, through direct contact with skin, or inhaling pesticide in the air. 

This may be more of a problem in low and middle income countries (who.int), and wikipedia.org also suggests that most pesticide related deaths occur in developing countries

At the consumer level, pesticide can get into/on food as pesticide residue, and can even get into the water supply. Although, some sources say that pesticides aren’t as much of a risk at the consumer level because the levels of pesticides aren’t high enough. The exception to this might be more vulnerable groups like children and infants, and pregnant women.

It’s worth noting that regulations or standards relating to pesticide use can differ between countries. The risk of of pesticide use might be lowered by following safer regulations and standards that outline lower risk pesticides and pesticide levels to use.

Some countries might have regulations with shortcomings regarding health and safety. International trade can also see foods produced under one set of regulations be exported to another country with another set of regulations.

As who.int describes, different pesticides have different functions, chemical makeups, and other variables that impact their profile. Dosage amounts, route of exposure, and other factors can all play a part in how a pesticide might impact human health.

ewg.org also goes into more detail about specific pesticides and types of pesticides, and describes their potential effect on human health.

wikipedia.org mentions that the quicker a pesticide degrades in the environment, the quicker it might lose it’s toxicity

 

There’s Various Environmental Issues That Pesticides & Fertilizers Might Contribute To

There’s a number of environmental issues that pesticides, and reactive nitrogen from fertilizer (and other fertilizer compounds and chemicals), might directly contribute to.

Just a few examples of environmental issues might include water pollution, air pollution, GHG emissions, and more.

Additionally, fertilizers require methane/natural gas to make, and there are the indirect environmental issues caused by natural gas drilling and fracking to consider.

 

The use of nitrogen and phosphorus fertilizers may be putting pressure on certain planetary boundaries

 

Applying nitrogen in excess has been linked to water and air pollution, depletion of the ozone layer, climate change and numerous human health concerns (calag.ucanr.edu). You can see a good diagram showing the impact of the nitrogen cycle in the calag.ucanr.edu resource.

 

The Use Of Fertilizer & Pesticide Has Potential Sustainable Resource Management (& Resource Depletion) Concerns

Firstly, pesticides and fertilizers require raw materials, mined minerals (like phosphate rock), chemicals and energy to make, and some of the resources required to make them may not be renewable.

Secondly, a portion of nitrogen fertilizers can either be washed away (particularly in areas with heavier rainfall), or can convert into nitrous oxide, before they can take affect on the crops they are applied to. When there is consideration for the resources that go into making nitrogen fertilizer, some question the sustainability of it from a resource management perspective

 

Pesticides & Fertilizers Can Negatively Impact Animals, Wildlife & Biodiversity (Potential Toxicity)

There’s a number of ways pesticides and sometimes fertilizers can negatively impact animals, wildlife and biodiversity.

This impact can be direct, such as when wildlife come into contact with/are exposed to some types of pesticide chemicals

Or, there can be more of an indirect impact where fertilizer may contribute to nutrient pollution in a water bod that aquatic species live in.

 

In Some Instances, Pesticides & Fertilizers May Contribute To Economic Loss

Pesticides may have an economic impact on wildlife to consider (some estimates say this runs into the billions)

And, if pesticides and fertilizers contribute to environmental pollution or other environmental issues, there’s the hidden upfront cost of how much clean up (say for example of a polluted water body), or addressing other environmental issues might cost.

Some of these costs may be difficult to accurately estimate.

 

Fertilizers & Pesticides May Contribute To, Or Mask The Effects Topsoil Loss & Land Degradation

Fertilizers and pesticides may be a contributing factor to some types of land and soil degradation.

They may also mask some of the long term effects of these problems, such as declining yield and land productivity.

 

Subsidies For Pesticides Or Fertilizers May Contribute To Some Problems

In some countries, subsidies for pesticides and fertilizers may lead to artificially pushing up demand, or, giving incentive to buyers to not use pesticides and fertilizers as effectively as they could.

These things can create a flow on effect of contributing to problems outlined elsewhere in this guide.

Having said this, some countries are in the process of decreasing pesticide or fertilizer subsidies.

 

Built Up Pesticide Resistance Can Compound Certain Issues

It’s possible that over time, certain crops can build up more of a pesticide resistance to certain types of pesticides.

What this means is that more pesticide chemicals have to be used.

This can compound certain problems that pesticide chemicals already contribute to

 

Too Much Fertilizer Application Can Impact Soil Fertility Factors

As just one example, when the soil receives too much of a certain nutrient from fertilizer, it can impede crops and plants being able to absorb other nutrients.

Applying fertilizer requires the right balance.

 

Stages At Which Pesticides & Fertilizers Might Impact Society

1. Manufacturing stage – energy and other resources used

2. Use of pesticides and fertilizers on farms – some pesticides and fertilizers can be lost before they take effect (such as fertilizers washing away), leaching into soil and water, air emissions, impact on wildlife, impact on humans, and so on

3. Consumer stage – pesticide residue found on food

 

Is Synthetic Pesticide & Fertilizer Use Increasing Or Decreasing?

Pesticides

… pesticide use has increased 50-fold since 1950 [where between 1940 and 1950 is considered to be the start of the ‘pesticide era’ in the US] … [and] Seventy-five percent of all pesticides in the world are used in developed countries, but use in developing countries is increasing (wikipedia.org)

 

Fertilizers

The use of synthetic nitrogen fertilizers has increased steadily in the last 50 years, rising almost 20-fold to the current rate … (wikipedia.org)

The use of phosphate fertilizers has also increased from 9 million tonnes per year in 1960 to 40 million tonnes per year in 2000 (wikipedia.org)

 

Other Notes On Pesticides & Fertilizers

Alternate farming methods, the use of biological pest control, the use of pest resistant engineered GMO crops, and selective insect breeding can all lead to the decrease in use of synthetic pesticides. 

The pros and cons of synthetic vs natural fertilizers can obviously be very different to one another

Some crops like legumes have the ability to fix nitrogen from the atmosphere, so may not need nitrogen fertilizer

 

Sources

1. Rosenstock T, Liptzin D, Six J, Tomich T. 2013. Nitrogen fertilizer use in California: Assessing the data, trends and a way forward. Calif Agr 67(1):68-79. – http://calag.ucanr.edu/Archive/?article=ca.E.v067n01p68

2. Aktar, Md Wasim et al. “Impact of pesticides use in agriculture: their benefits and hazards” Interdisciplinary toxicology vol. 2,1 (2009): 1-12. – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095/

3. https://www.ewg.org/foodnews/summary.php

4. Conrad, Z., Niles, M.T., Neher, D.A., Roy, E.D., Tichenor, N.E. and Jahns, L., 2018. Relationship between food waste, diet quality, and environmental sustainability. PloS one13(4), p.e0195405. – https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195405

5. https://www.who.int/news-room/fact-sheets/detail/pesticide-residues-in-food

6. https://en.wikipedia.org/wiki/Fertilizer

7. https://en.wikipedia.org/wiki/Pesticide

8. https://kids.frontiersin.org/articles/10.3389/frym.2019.00041

9. https://www.seasol.com.au/home-garden/handy-hints/seasol-guide-to-fertilisers/seasols-guide-to-fertilisers/

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