Magnesium, Soil Health and Our Food
Why is there less magnesium and other minerals and nutrients in our soil?
Soil is the foundation of life on Earth. It’s where we grow our food, the place where countless organisms thrive, and the support system for much of the planet’s biodiversity. But over time, we’ve seen a steady decline in the nutritional content of the soil, and consequently, the food that comes from it. Why our soil is becoming less fertile?
The Decline of Soil Health:
Soil health refers to the ability of soil to sustain plant life, support biodiversity, and maintain ecological balance. It’s about more than just the soil’s ability to grow crops—it’s the richness of the soil, its mineral content, and its microbiological diversity. But over the last century, something troubling has been happening: the minerals like magnesium, and nutrients that once enriched the soil seem to be depleting, leading to nutrient-poor soil and, ultimately, nutrient-deficient crops.
1. Intensive Agricultural Practices
Modern farming has heavily relied on industrial-scale monocropping, where a single crop is grown year after year in the same soil. This practice exhausts specific nutrients over time because the same nutrients are drawn from the soil repeatedly without replenishment. For example, crops like corn, wheat, and soybeans deplete essential nutrients like nitrogen, phosphorus, magnesium, and potassium, and without proper crop rotation or soil management, these nutrients aren’t getting replaced.
Additionally, the overuse of synthetic fertilizers has led to an imbalance in soil nutrient levels. While fertilizers add certain nutrients (such as nitrogen), they often don’t supply the full range of minerals and trace elements that plants need to thrive. This results in soil that may look fertile on the surface but lacks the deeper, more diverse nutrition necessary for healthy plant growth.
2. Soil Erosion and Loss of Topsoil
Soil erosion, driven by deforestation, overgrazing, and heavy rainfall, has become a major problem in many parts of the world. The topsoil, which contains the most nutrients and organic matter, is washed away, leaving behind nutrient-poor subsoil. According to the United Nations, about 33% of the world’s soils are already degraded due to erosion.
This loss of topsoil means that even if crops are planted, they don’t have access to the nutrients they once did. This degradation not only reduces the quantity of food we can grow, but it also impacts the quality of the food.
3. Chemical Pesticides and Herbicides
The widespread use of pesticides and herbicides in conventional farming has harmed soil health in multiple ways. These chemicals not only kill pests but also disrupt the delicate balance of microorganisms in the soil. Healthy soil relies on a wide variety of bacteria, fungi, and other microorganisms that break down organic matter, fix nitrogen, and make nutrients available to plants.
Over time, the overuse of chemicals reduces soil biodiversity, which weakens the soil’s ability to regenerate naturally and maintain its nutrient content.
4. Decline in Organic Matter
Organic matter, which comes from plant and animal residues that decompose in the soil, is crucial for maintaining soil structure and fertility. It holds water, provides nutrients, and serves as food for microorganisms. Unfortunately, modern farming practices have reduced the amount of organic matter in the soil, primarily through intensive tilling, the burning of crop residues, and a lack of cover crops or organic matter inputs.
Without adequate organic matter, soil becomes compacted, less aerated, and less capable of holding onto essential nutrients. This not only reduces the soil’s fertility but also impacts its ability to store carbon, contributing to climate change.
Why Are Fewer Nutrients Found in Our Food?
If our soil is losing nutrients, it’s no surprise that the food we grow in it has less nutritional value. Several studies have shown that the nutrient content of fruits, vegetables, and grains has decreased significantly over the past 50 years. Here's how this nutrient loss impacts our health:
1. Lower Levels of Essential Nutrients
Crops grown in nutrient-depleted soil are often deficient in key vitamins and minerals, such as iron, zinc, magnesium, and calcium. For instance, research has shown that vegetables like spinach and broccoli now contain lower levels of iron and calcium than they did decades ago.
This means that even if we eat plenty of fruits and vegetables, we might not be getting the same amount of nutrients that our grandparents did, leading to potential deficiencies and health issues, particularly in areas where diets already lack diversity.
2. Decreased Soil Microbial Activity
A lack of biodiversity in the soil, which results from chemical fertilizers and pesticides, affects the plants’ ability to absorb the full spectrum of nutrients. Healthy, living soil supports a diverse community of microorganisms that help plants take up essential minerals. Without these microbes, plants struggle to access nutrients, leading to nutrient-poor food.
In the long run, this can contribute to chronic health problems for those who rely on these nutrient-deficient crops as a primary food source.
How Can We Improve Soil Health?
While the decline of soil health is a serious issue, there are solutions and practices that can help restore nutrients and improve soil fertility. Here are some steps we can take:
1. Organic and Regenerative Farming Practices
Crop Rotation: Planting different types of crops in rotation helps prevent the depletion of specific nutrients, as different plants require different nutrients.
Cover Cropping: Planting cover crops like clover, legumes, or alfalfa helps restore nitrogen to the soil, prevents erosion, and adds organic matter back into the soil.
Composting: Adding compost to soil provides a steady supply of organic matter and micronutrients, improving soil structure and promoting healthy microbial life.
Reduced Tillage: Minimizing tilling helps preserve soil structure, organic matter, and beneficial microorganisms.
2. Reintroducing Biodiversity
Encouraging biodiversity, both in the crops we grow and in the organisms living in the soil, can help restore balance to the soil ecosystem. This includes planting a mix of crops, leaving some areas of land wild, and avoiding chemical inputs that harm beneficial insects, fungi, and bacteria.
3. Soil Testing and Responsible Fertilization
Regular soil testing helps farmers and gardeners understand what nutrients their soil needs. Using fertilizers wisely—based on these tests—can help ensure that nutrients are replenished without overloading the soil with chemicals.
4. Advocating for Sustainable Practices
On a larger scale, advocating for policies that support sustainable agriculture, including soil conservation programs and the reduction of harmful chemical inputs, can help mitigate the damage done by industrial farming practices.
5. Support Regenerative Farms
Shop for your produce, meat, eggs, and dairy at local farms that you trust who are making the extra effort. Buying only nutrient dense foods for your family will push these monster commercial farms into regenerative agriculture.