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Synthetic vs. Organic Fertilizers: What's The Difference?

Published:

August 1, 2024

Key Takeaways:

Both organic and inorganic fertilizers enrich the soil with three primary nutrients: nitrogen, phosphorus, and potassium.
Organic fertilizers are more expensive and deliver nutrients slowly but encourage long-term soil health.
Synthetic fertilizers are usually cheaper and act faster but may harm soil biology or cause overfertilization if not used properly.
It is common to use organic and inorganic fertilizers simultaneously throughout the season, adjusting the ratio according to crop needs and environmental considerations.

One of the most enduring debates among anyone who grows plants, from commercial farmers to backyard hobbyists, is over whether one should use synthetic or organic fertilizers. While both types of fertilizer accomplish the same basic goal of providing nutrients to plants, the methods and results can be very different.

Further, other factors may come into play, such as concerns over which type of fertilizer will be less harmful to the environment, or bring better long-term results.

Cropler was founded to help farms succeed through crop monitoring and smart planning. We're dedicated to your field's success! So, let's talk about the pros and cons of both organic and chemical fertilizers.

The Basics of Fertilizers

As a quick refresher, all fertilizers are based around three primary ingredients: nitrogen, phosphorus, and potassium, also called the NPK ratio.

In nature, these organic nutrients are continually replenished through the death and decay of creatures in the soil, such as insects and earthworms. However, in farmed land, these nutrients tend to be depleted over time and have to be supplemented. This creates the need for fertilizer, which is periodically added to the soil to ensure crops remain healthy.

Over-fertilization and under-fertilization can both damage crops, so finding the right balance is essential. Understanding the differences between types of fertilizers can help ensure your crops receive the best nutrition possible.

Organic Fertilizers

Organic fertilizers are created to mimic the same mix of nutrients, minerals, and other organic chemicals that would be found in untouched soil. Ingredients typically include worm casing, bone meal, or fish emulsions. These natural fertilizers don't merely nurture the plants; they also provide food for the microbiome that develops in the soil around plants' roots. In general, a plot treated with organic fertilizer will closely resemble the natural environment. However, biofertilizers tend to take longer to work, often requiring months or years to enrich depleted soil. Long-term planning is necessary to deploy organic nutrients.

Proponents of organic fertilizer believe that maintaining a more natural balance of nutrients and encouraging microbial health enhances the long-term viability of the soil. Some research backs this up as well, such as this 2024 study from Heliyon. In addition, research from 2019 suggests that organic fertilizer tends to increase soil pH levels and fight soil acidification which can be caused by synthetic substitutes.

Factor	Synthetic	Organic
Price	Inexpensive	Expensive
Nutrient Amounts	Predictable	Varies by batch
Nutrient Delivery	Fast	Slow
Visible Changes	Rapid	Extended timeframe
Amount Needed	Less	Substantially more
Soil Effects	Harms soil biology	Encourages soil health
Environmental Impact	Potentially high	Minimal
Best For	Saving damaged crops; hungry species	Long-term soil health

Synthetic Fertilizers

As the name suggests, synthetic fertilizers are created in a lab, made by directly mixing nitrogen, phosphorus, and potassium. Manufacturers typically also add in small amounts of other inorganic compounds and minerals—including iron, copper, boron, and zinc—as micronutrients.

In most cases, synthetic fertilizer comes in a concentrated liquid form and is designed to be water-soluble. It is then sprayed directly on or near the plants, providing them with a nearly instant infusion of nutrients. Other variations are granular and are placed near the plants.

Regardless of the delivery method, the rapid action of synthetic fertilizers can quickly perk up crops in depleted soil. They are also often preferred for demanding crops such as tomatoes which require a nutrient-rich environment. Be careful, though: the high concentration of nutrients can make it easy to over-fertilize plants, or burn their roots.

However, there are significant concerns about the long-term health of soil which is continually treated with synthetic fertilizer alone. Besides the tendency to increase acidity, they do not support microbial biomes, and may even kill off microbial life in the soil, as the 2021 research indicates. There are further concerns, still being studied, about the possibilities of long-term pollution to nearby land and water—such as links between increased high-nitrogen fertilizer use in coastal areas and deadly algae blooms offshore.

Which Should I Choose?

If a farm must choose one or the other, organic is likely the best option for long-term results and better soil health. However, synthetic fertilizers can be deployed for specialized crops or to quickly rehabilitate plants in poor soil.

Using Organic and Synthetic Fertilizers Together

Researchers are increasingly recommending the use of both organic and synthetic, artificial fertilizers together, rather than relying wholly on synthetic fertilizers. If you currently rely only on chemical farming, it is sometimes recommended to deploy a doubled amount of organic fertilizer over the course of a season to rebuild the soil, before moving to the standard recommended amount thereafter, then using inorganic fertilizers sparingly as needed. However, this recommendation should be adjusted according to the current state of the soil, environmental conditions, and crop needs.

How to Switch From One Fertilizer Type to Another

It is not common to rely solely on one fertilizer type. The focus is usually on adjusting the combination of organic and inorganic chemicals rather than transitioning from one to another completely. This change is gradual and situational, depending on the current and expected soil condition, pH, nutrient levels, the needs of your particular crops, and economic considerations.

The switching, or adjustment process is based on gradually reducing the amount of organic fertilizers while increasing the amounts of inorganic ones, or vice versa. To handle this process correctly, it’s important to run soil tests regularly to monitor soil health and prevent nutrient deficiencies. Another indicator of successful switching is a healthy crop—yellowing or purpling leaves, poor growth, delayed flowering, and other disturbing signs can show nutrient deficiency or excess caused by improper fertilizer use.

When you have questions, we'll help you find the answers you need to take control of your fields and the harvest you care about. Contact Cropler to discover more about our products and the ways we help you proactively protect your operations from the effects of crop diseases. Discover More

Cost of Organic and Synthetic Fertilizers

Synthetic fertilizers are almost always much cheaper than organic options. They are also typically less labor-intensive to deploy.

Organic fertilizers typically come in large bags, and require substantially more product to fertilize a plot, compared to synthetic chemicals. However, volume is not the only reason for higher costs. The production of organic fertilizers is more expensive, it requires a more extensive quality control and certification process, and distribution costs may be higher.

However, cost is not the only factor in choosing a fertilizer type. The choice should also be guided by crop needs, soil health, and environmental considerations.

Cropler: Your Personal Plant Guardian

Cropler brings modern data-tracking to farming. Our weatherproofed agri-cameras provide 24/7 plant monitoring in both visible and infrared spectrums. Through a web platform, you can monitor the health of your crops remotely, which also allows you to analyze the need for fertilizers and their effectiveness. Try our portable agri-cameras and a robust online platform to precisely track your crops' health day by day, and season by season. Contact us today to learn more!