The Prevalence of Glyphosate in Agriculture

In 2014, glyphosate usage reached an astounding 1.8 billion pounds worldwide. By 2016, genetically modified crops accounted for 56% of this usage. However, it’s important to note that non-GMO crops are often treated with glyphosate, particularly just before harvest, which explains why some non-GMO certified foods still contain traces of this herbicide. Glyphosate is utilized on around 100 different crops across 130 countries.

The majority of farmland globally—99%—is farmed conventionally, allowing glyphosate use, while only 1% is organic. This heavy reliance on conventional farming techniques suggests that glyphosate use will continue to rise as more crops are cultivated in this manner.

Many people mistakenly believe there's only one formulation of glyphosate available. However, since the Round-Up patent expired in 2000, over 750 glyphosate-containing products have entered the market. Though organic farming prohibits glyphosate application, residue from this herbicide is still being detected on organic crops. Research indicates that individuals consuming mostly organic diets have approximately half the glyphosate levels in their urine compared to those with conventional diets, underscoring the pervasive nature of glyphosate exposure.

The Influence of Glyphosate on the Carbon Cycle

Studies comparing glyphosate-sensitive soybeans to resistant varieties reveal that glyphosate is metabolized into aminomethylphosphonic acid (AMPA). A 2011 study assessed the impact of AMPA on plant growth, chlorophyll levels, and photosynthesis. Results showed that increased AMPA concentrations led to significant plant damage, with chlorophyll content dropping by up to 66% and photosynthesis rates decreasing by as much as 88%.

Globally, we apply 825.8 million kilograms of glyphosate, neglecting its critical role in the carbon cycle. AMPA disrupts the ability of plants to exchange gases like oxygen and carbon dioxide through their stomata. Glyphosate's interference with photosynthesis not only limits the carbon absorption capacity of plants but also contributes to the herbicide's presence in water bodies and rainfall—an alarming global issue.

As glyphosate has been utilized in agriculture since the 1990s, its increasing application over the years has significant implications for climate dynamics. The reduction in photosynthesis hinders plants' capacity to absorb atmospheric CO2. Moreover, glyphosate that isn't converted to AMPA is broken down into CO2 by soil microbes, further exacerbating the situation.

Research from 2018 demonstrated that glyphosate application leads to a decrease in soil carbon levels. As plants decompose, they contribute organic matter that helps sequester carbon in the soil. Therefore, when glyphosate hinders photosynthesis, it logically follows that treated fields yield less plant biomass.

Policy Dialogue: Can Glyphosate Play a Role in Achieving Greater Biodiversity?

This dialogue explores the intersection of glyphosate use, biodiversity, and agricultural practices, questioning the long-term sustainability of current methods.

Glyphosate's Half-Life and Its Longevity in Soil

Research indicates that the half-life of glyphosate in soil ranges from 2 to 197 days. To reach a level where only 3% remains, it takes five half-lives. The duration glyphosate persists in the soil largely depends on its physical, chemical, and biological properties. Given that glyphosate is often reapplied multiple times a year, it remains a constant presence in our environment.

The potential of a plant-based diet to mitigate climate change is compromised by conventional farming practices that rely heavily on glyphosate. The staggering 1.8 billion pounds of glyphosate used annually diminishes the capacity of numerous plants to sequester atmospheric carbon.

The Role of Manure in Sustainable Agriculture

Farmers have long recognized that manure is an effective fertilizer. When applied to well-managed pastures, manure supports soil health and enhances carbon sequestration, making grass-fed, pasture-raised beef a carbon-negative food source. Conversely, conventional monocrop farming, irrespective of glyphosate use, cannot achieve carbon negativity due to its resource-intensive processes.

While discussions around deforestation often target livestock production, it is vital to acknowledge that glyphosate's role in the carbon cycle, particularly in plant-based agriculture, is frequently overlooked. As it stands, agriculture currently emits more greenhouse gases than livestock.

Instead of debating the merits of plant-based versus animal-based diets—both of which together account for only 10% of greenhouse gas emissions—efforts should focus on identifying and addressing the main contributors to emissions: transportation, energy production, and industrial activities.

References:

Writing remains my passion, and I thrive on research and sharing knowledge. If you appreciate my work, consider supporting me by becoming a Medium member.