Abstract:

In this blog I will be addressing controversies surrounding the practices of pesticide application and soil tilling in our modern farming systems. There remains much controversy regarding their negative and positive effects on the soil, the overall environment, and human health in particular, which has fueled continuing worldwide debate. I will advocate for the reduction or even elimination of tilling and pesticide practices in modern farming. Tilling disrupts soil structure, water filtration, and reduces microorganisms vitality and the nutrient content in the soil essential to healthy plant growth and development while pesticides kill microorganisms and decrease overall soil health and organism diversity. I believe that there are better, less invasive methods of cultivating our planet that preserve essential nutrients and microbes in our soil rather than decreasing soil fertility and, in turn, negatively impacting plant health and growth. I provide solutions and substitutions herein to replace the important role of pesticides and tilling with evidence supporting why these alternatives are superior overall for the health of plants, soil, the environment, and humans than the current methods widely implemented. Counter-arguments include the claim that pesticides and tilling are extremely efficient, and putting the proposed more sustainable solutions into place would require a lot of work and add additional resources from farmers in comparison to the efficiency tilling and pesticides already provide. While aspects of these claims have merit, I plan to refute this by providing evidence showing the severely adverse effects of these ‘efficient’ methods and proving that, in the long run, putting the proposed more sustainable farming practices into place will be more than worth the manpower and resources that are required and, in turn, make our farming industry significantly more sustainable.

Why Do We Use Pesticides and Tilling Now?

The farming industry is a significant and essential industry in our national and global economies, providing food and other resources for people and companies. But, have you ever stopped to think about how all of these products are grown? They are the result of much hard work and labor mass producing our crops, and farmers are frequently extremely underpaid for the amount of time, effort, and labor they dedicate to providing these important crops to consumers. However, many farming techniques are often implemented to increase the efficiency of the farming process and take some of the workload off of these farmers’ shoulders.

The image above depicts a pesticide distribution machine which evenly and efficiently distributes chemicals to grass, crops, or other growing plants. (19) Pesticides are chemicals that are designed to be sprayed on crops to prevent, kill, and control unwanted pests like insects, fungi, and weeds that inhibit their growth, which often limits the amount of crops that can be harvested and sold. Pesticides are sprayed on plants during growth using either pesticide-distributing machines or by hand, and they can be completely washed off prior to consumption.

The image above depicts a tractor operated by a farmer designed to efficiently till the soil in preparation for crop growth. (21, 22) Tilling is a method designed to break up and mix organic matter into the soil while also preventing and killing weeds. Tilling can be performed in a variety of different ways including by hand or with machines like plows or cultivators. 

While these methods appear to make a clear, positive difference in the efficiency of the farming industry, there continues to be significant debate around their long-term effects on the soil, crops, and even humans, and whether or not the harm they cause outweighs the benefits they provide. 

Why Do We Use Pesticides?

There are numerous variations and mixtures of pesticides that have been developed to achieve essentially the same purpose: kill and prevent pests and weeds that could harm the health of the plants they are used on. One problem with using the same pesticide for a long period of time is that the weeds and pests that it was initially designed to kill and prevent often develop immunity to its effects. This requires formulas and potencies of pesticides to be altered over time after they stopped performing their function effectively. In modern day, pesticides designed for food use fall under three main categories: insecticides, herbicides, and fungicides. Insecticides control insects and other pests that eat the plants and interfere with their healthy growth and development . Herbicides control weeds which use up the nutrients, water, sunlight, and growing space needed by the plants, inhibiting their healthy growth and development. Fungicides control plant molds and diseases which pose a threat to the health, vitality, and growth of plants.

Above are examples of pesticides designed to be applied to household plants or gardens to serve the purpose of preventing pests on a small scale. (23). When used on a larger scale, pesticides require a man-operated machine to be able to distribute them across large-acreage plots of farmland. Pesticides tremendously increase the productivity of crop growth and the efficiency of maintaining plant health during the growing process, which is why they are utilized for both small and large-scale gardens and farms. By protecting the crops as they grow, pesticides increase the amount of quality food that can be ultimately produced and sold to consumers, and they provide a larger quantity of fruit, vegetables, and other crops that are much healthier than highly processed foods like packaged snacks and fast food.

Why Do We Till?

Conventional tillage is one of the earliest farming methods that has been consistently used and relied on in conventional farming. It began as a method reliant on manual labor and evolved to be performed by machinery to increase efficiency. Its function is to better prepare the soil to receive seeds by removing weeds and pests and mixing organic matter into the soil. (11) It also allows for aeration and warming of the soil from the sun. The amount of tilling that a bed of soil requires depends on the region and its climate, and tilling has much flexibility regarding the extent to which the technique can be altered to fit the needs of the soil beds in that region. (9) Compared to manual tilling, which requires much more physical labor from farmers, tilling machines are much easier to operate. Tilling can also vary in intensity and the amount to which the technique disturbs and breaks up the soil. The image below depicts these tilling machines performing tilling, breaking and mixing up the solidified portion on the surface of the soil, after which the more nutrient-rich, dark soil is exposed for seeding. (24, 25)

The Unintended Consequences of Pesticides

Pesticides and tilling may sound like they provide great benefits to our farming industry, and in some ways they do, but what most people fail to understand is their unintended consequences. In addition to their positive attributes we know how much damage is actually caused by these pesticides. Pesticides were designed on the idea that they could solely affect the targeted organisms, i.e. weeds, pests, and fungi. Their increased widespread use in modern farming has proven otherwise. We now know environmental issues that pose a threat to the future health of our soil and even our own health. The pesticide-grown plant cycle was originally developed as a result of war. It caused people to have to find ways to increase the efficiency and profit of the crop cycle, and the implementation of pesticides was one solution to this problem. The modern pesticides were actually developed by the same person, a Nazi scientist, who designed the gases used in the gas chambers during the Holocaust. Pesticides have been contributing to the widespread decline in insect populations ever since. (10) Non-target, harmless insects that reside in the soil like earthworms, ants, and beetles, and even some pollinators like bees are sometimes also killed in addition to the target organisms. Pesticides also affect microorganisms that reside in the soil. (1) These organisms are responsible for decomposing dead plants and animals to be used as nutrients for plants, cycling nutrients such as carbon and nitrogen throughout the soil, and naturally regulating some of the pest populations. Microbes are some of the most important organisms within the soil, as they regulate and manage almost every aspect of plant growth. (12) The reduction of these microbes due to pesticides poses a huge threat to the health of the soil and, in turn, the growing crops that rely on their benefits. Soil that is biologically diverse contains great numbers of varying microorganisms, nutrients, soil-residing organisms, water regulation channels, and more aspects that all provide for each other and nourish the plants growing within the soil. With this loss of microbial diversity also comes the reduction of the soil’s ability to sequester carbon.

As the figure above shows, plants are able to sequester carbon from the atmosphere by use of photosynthesis. As we begin to lose microbial diversity in soil, the plants become less healthy and prosperous and, in turn, are limited in the amount of carbon they can sequester from the atmosphere. (20)

As plants die, they decompose into the soil and the carbon and nitrogen that they absorbed from the atmosphere through the process of photosynthesis gets absorbed into the soil. From there, the carbon and nitrogen gets used up by new, growing plants, as they are two of the most vital nutrients for plant health. Because pesticides are killing the microbes responsible for breaking down these plants, the amount of nitrogen and carbon occurring naturally in the soil is decreasing drastically, which adversely affects the nutrients available to growing plants.

Do Pesticides Contribute to Climate Change?

In addition to the direct negative effects that pesticides have on the environment, their manufacturing, transportation, and application also negatively impacts our atmosphere by releasing greenhouse gasses in the air. The transportation of pesticides as well as the machines typically used to apply it efficiently both require fuel, which in turn releases greenhouse gasses into the air. When pesticides are made, carbon dioxide, methane, and nitrous oxide, three of the most abundant greenhouse gasses, are emitted into the atmosphere. (4) Increased manufacturing of these pesticides results in a greater amount of these gasses being released, contributing to the already challenging issue of climate change and global warming. (13) The production of the more popular brands of weedkiller, called Roundup, involves the mining of phosphate ore which is needed to produce glyphosate, the active ingredient that kills and prevents pests, weeds, and fungi. This process of mining phosphate pollutes water and the atmosphere, and it destroys the habitats of wildlife.

How Do Pesticides Impact Humans and Animals?

One of the most concerning impacts of pesticides is the threat they pose to human health. (7) Since pesticides are directly sprayed onto crops, there is some chemical residue that gets washed away due to rain or routine watering. When it rains, most of the water gets absorbed by the soil, but the water that is unable to be absorbed remains on the surface and creates runoff. The amount of pesticide that gets washed off of the plants mixes with the runoff water and travels to streams or rivers, smaller bodies of water that eventually lead to the ocean. Warmer waters in the ocean lead to an increase in pesticide toxicity, which can have a severe impact on the development, reproduction, swimming ability, and behavior of fish and other marine organisms. Runoff also poses the risk of  pesticides contaminating our water, which can lead to pesticide poisoning as the chemicals within it are meant to kill pests and weeds, not to ingest. In addition to pesticide contamination in water, if crops are not thoroughly washed before consumption, there is also the risk of ingesting the pesticide chemicals by humans via pathway. In addition to direct pesticide poisoning, the reduction of nutrients in the soil caused by pesticides also leads to much less nutritious crops that lack important minerals for human health. With the current rate at which pesticides are decreasing soil health, eventually there won’t be enough fertile topsoil to grow any crops.

How Costly Are Pesticides?

The cost of pesticide production and distribution also poses an economic issue for farmers. The price of pesticide distribution per acre is slowly but noticeably climbing. 

According to this figure from FarmDoc Daily, which only shows costs as late as 2017, there has been and continues to be a gradual increase in costs per acre in Central Illinois alone due to the increasing demand for pesticides by farmers who rely on them for their efficiency. (26) The development, experimentation, production, packaging, and transportation of pesticides all additionally have their own individual costs, which all add up to be costly for farmers to afford and companies to produce. As per the graph, pesticide costs for the future are rising and will begin to pose financial problems if the costs rise to be too much for farmers to afford.

Are There Substitutes for Pesticides?

We cannot simply remove pesticides from the equation to solve the problems they cause, as they do serve an important purpose in the efficiency and regulation of crop growth, but biopesticides can be substituted on the same large scale and they function as effectively as chemical pesticides do. These are a certain type of pesticide derived from natural materials like animals, plants, and bacteria rather than created through the use of chemicals. Similar to pesticides, biopesticides fall under 3 categories: biochemical, microbial, and plant-incorporated-protectants (PIPs). Differently from pesticides, which control pests using chemicals, biochemical pesticides include substances designed to interfere with pest mating pheromones and plants that attract these pests into pre-planted traps. (15) Microbial pesticides use a virus, bacteria, or fungus as the active ingredient to control numerous pests, and the type of fungi or bacteria used in these pesticides can be altered to target a specific pest or group of pests. Plant-incorporated-protectants, or PIPs, are substances produced by the targeted plants from material that has been genetically added to it, such as a protein, which naturally prevent the pests targeted by the gene added. On a mass scale, biopesticides are the best option as there are many different types to best fit the crops in a specific region. Best of all, biopesticides perform the tasks of chemical pesticides without negatively affecting the soil, the environment, or people since they are made from materials derived from nature.

The image above shows a venn-diagram of the three different types of biopesticides compared to some of the general chemical pesticide formulas. (29)

The Unintended Consequences of Tilling

The process of tilling involves machinery like plows to essentially turn over the top 6-10 inches of soil to prepare it for seeding. This functions by mixing organic matter such as dead, decomposing plant or animal manure with the top portion of the soil, increasing its nutrient content. Additionally, it provides the soil with aeration and allows the sun to warm it. All of these may sound great, but the reality is that tilling causes so much damage to the soil that it poses a threat to its future fertility for farming. Tilling is extremely invasive to the structure of the soil, so too much of it can cause damage. When tilling is performed, it loosens and removes plant matter that has died and is in the process of decomposing into the soil, which leaves the top layer of the soil exposed and bare. (17) It also breaks down the natural structure that undisturbed soil forms over time. This structure is responsible for absorbing water, similar to a sponge, and creating a stable structure to filter that water as well as nutrients and other minerals through it to organisms like plants, insects, and microorganisms. Bare, exposed soil that is deficient in nutrients and water which help it to keep its structure due to tilling is extremely likely to be eroded by water and wind, meaning washed or blown away. In addition to stripping the soil of water and nutrients and increasing the possibility for erosion, tilling, like pesticides, kills the microbes and insects living within the soil that all depend on each other in a symbiosis that increases soil productivity and plant growth. This decrease in soil-residing organisms also adversely decreases the diversity of the soil.

Does Tilling Contribute to Climate Change?

Soil is one of the most carbon-absorbing substances on the planet. It draws carbon from the atmosphere and from decomposing plants and uses it for the plants and organisms living and growing within it. Because tilling decreases the nutrient content of soil, there is much more carbon in the atmosphere that isn’t getting absorbed by the once nutrient rich soil. (2) This means the amount of greenhouse gas emissions entering our atmosphere will continue to grow with little to no regulation. This contributes negatively to the ever-growing issue of global climate change. Additionally, by breaking up the soil, tilling exposes already existing carbon within it to oxidation and releases it back into the atmosphere, contributing to global warming. Like pesticides, the production, fuel, and maintenance of the plows that perform tilling releases even more greenhouse gasses in addition to carbon like methane and nitrogen.

How Costly Is Tilling?

The cost of tilling also poses an issue to farmers. Manufacturing plows for conventional tilling costs a lot, let alone the amount farmers have to pay to maintain them and keep up with fuel consumption.

Fuel costs in particular, as shown above in a study done by the University of Minnesota, add up over time with upkeep, especially regarding the acreage and the ever-rising price of diesel which is required to fuel these tilling machines. (18) It costs $6,125 for strip-till, $7,070 for chisel plow and field cultivation, and the price rises all the way to $16,206 for moldboard plowing and field cultivation.

The figure above depicts an updated data figure of the cost of gas per gallon in the US all the way to October of 2022. (28) This further reinforces the argument that the prices of gas for tilling are continuing to rise and have more than doubled per gallon over the last two years. The money farmers are investing in tilling could easily be invested in more sustainable, less invasive alternatives that serve the same purpose and don’t cost nearly as much.

Are There Substitutes for Tilling?

Some of the most viable solutions already being implemented in conventional farming are no-till methods and the use of cover crops. One of the essential benefits of tilling is the mixing and incorporation of dead, decomposing plant matter into the soil to increase nutrient content. However, plants are naturally decomposed by the microbes in the soil, their nutrients absorbed in the soil along with them. Cover crops are widely used to increase the nutrient content of the soil. They are essentially plants that can be varied based on the nutrient type the crops in that region require, ranging from carbon to nitrogen and other nutrients and minerals. (5) They are planted in the beds prior to crop planting so that when they die, they decompose and their nutrients are absorbed into the soil to prepare the beds for crop planting.

The figure above shows the long-term effects that no till methods have on the soil. (27) Though no-till takes some time for the benefits on the soil to be visible, the fertility and nutrients in the soil are preserved, so land plots that don’t use tilling are usable for much longer than plots that rely on the harsh, structure-disrupting function of tilling machines.

Cover crops function in the same way tilling does without the numerous negative effects it causes to the soil over time. One largely disputed issue about cover crops, however, is that they take time out of the crop season because they are required to be planted directly in the beds before they can be used. While this is the case, the extent to which soil diversity is decreased due to tilling requires an alternate solution to combat these detrimental effects. The amount of nutrients that get absorbed into the soil from cover crop placement is much more beneficial for the soil long-term despite its slightly lower efficiency. (8) No-till is a method in which the soil beds are left undisturbed, preserving the soil structure, water absorption, and natural nutrients absorbed by the soil. (3) Without tilling, plants naturally die and cycle through the soil, performing the job of tilling without the destruction of the soil’s microbiome and structure. As a result, soil beds last many additional seasons and aren’t nearly as subject to erosion when till methods are implemented. (6) No-till also reduces the cost that conventional farmers would otherwise have to pay for the machinery that performs tilling as well as fuel and maintenance of the cultivation machines. While tilling was designed to eliminate a large portion of the labor endured by farmers, operating the machines still requires labor similar to planting cover crops or even eliminating till in conventional farms.

Key Takeaways:

Why is any of this important? The health of our environment is slowly declining, and a lot of it is induced by human action. It is our responsibility to start making more sustainable changes, starting with farming. Soil does so much more than just provide a base for plants to grow; it regulates the carbon and nitrogen concentrations in our atmosphere, it filters groundwater, and it creates diverse ecosystems of insects and other microorganisms. The industrialized, efficient solutions that we have put in place in our modern conventional farming industries, despite providing a positive short term benefit, are now proving to have an extremely negative impact in the long-term if we continue in the technological direction we currently remain headed in.

The image above demonstrates the benefits of no till farming, which include less carbon being released from the soil, more water capacity, and decreased machinery fuel costs. (14) This shows just how much a difference removing this method from conventional farming can make to the health of our soil. Pesticides that are meant to protect crops and plants from unwanted pests, weeds, and fungi are stripping the soil of its nutrients and water, which will continue to limit the amount of usable, fertile soil in the future. Tilling that is meant to prepare the soil for seeding by mixing in decomposing organic matter is destroying the natural water filtration system that the soil structure and microbes provide, reducing the amount of water it’s able to absorb, increasing the possibility of erosion, and limiting the amount of atmospheric carbon the soil can absorb. Biopesticides, cover crops, and no-till substitutions for these modern farming tools may take some effort to implement, but the long-term positive benefits they clearly provide to the health of the soil, crops, organisms, and even people will prove to be worth it.

Works Cited:

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