Basalt - A TerraSoil Overview

What is Basalt?

Basalt, a volcanic rock, is gaining attention for its numerous benefits in organic agriculture. This naturally occurring material offers advantages for plant health, soil quality, and environmental sustainability. This overview delves into basalt's specific benefits to plants, the role of soil microbes and fungi in nutrient availability, its potential in CO2 reduction, the importance of particle size, and its sustainability in organic farming, supported by scientific research.

Specific Benefits to Plants

Basalt is rich in essential minerals such as calcium, magnesium, iron, and trace elements that are crucial for plant growth. These minerals improve soil fertility and enhance plant health. Several studies highlight the positive impacts of basalt on plant growth and yield:

1. Enhanced Nutrient Availability: Basalt releases minerals slowly over time, providing a sustained supply of nutrients. This slow release is particularly beneficial in organic farming, where maintaining long-term soil fertility is crucial.

2. Improved Soil Structure: Adding basalt can improve soil structure, enhancing water retention and aeration, leading to better root development and increased drought resilience.

3. Increased Crop Yields: Research has shown that basalt can significantly increase crop yields. Reports show that tomato plants grown in basalt-amended soil produced more fruit compared to those grown in non-amended soil.

4. Enhanced Disease Resistance: The mineral content of basalt can strengthen plant cell walls, making them more resistant to diseases and pests.

Role of Soil Microbes and Fungi

Soil microbes and fungi are crucial in making the nutrients in basalt available to plants. Mycorrhizal fungi, in particular, form symbiotic relationships with plant roots, extending their reach and efficiency in nutrient uptake.

1. Mineral Weathering: Microorganisms secrete organic acids that help dissolve basalt particles, releasing essential minerals into the soil, a process known as mineral weathering.

2. Nutrient Cycling: Soil microbes decompose organic matter, cycling nutrients back into forms that plants can absorb. The presence of basalt can enhance this microbial activity, promoting a healthier soil ecosystem.

3. Mycorrhizal Associations: Mycorrhizal fungi enhance the surface area of plant roots, improving their ability to absorb water and nutrients. The minerals released from basalt can be more readily taken up by plants through these fungal networks.

Potential Benefits Regarding CO2 Reduction

The use of basalt in agriculture has potential benefits for reducing atmospheric CO2, primarily through enhanced weathering, where basalt reacts with CO2 in the soil and air, forming stable carbonates stored in the soil.

1. Carbon Sequestration: As basalt weathers, it captures CO2 from the atmosphere, helping to mitigate climate change. Beerling, D. J., Leake, J. R., & Long, S. P. highlighted that enhanced weathering of basalt could sequester significant amounts of CO2, contributing to global carbon reduction efforts.

2. Soil Carbon Storage: The improved soil structure and increased organic matter from basalt amendments can enhance soil's ability to store carbon, further contributing to CO2 reduction.

The Effect of Particle Size

The particle size of basalt influences its effectiveness in soil amendment. Smaller particles have a larger surface area to volume ratio, enhancing their weathering rate and nutrient release.

1. Finer Particles: These weather more quickly, providing a faster release of nutrients. However, they may also be more easily washed away, reducing their long-term benefits.

2. Coarser Particles: These provide a slower, more sustained release of nutrients, are less likely to be lost through erosion, and can contribute to soil structure over a longer period.

Research indicates that a mix of particle sizes offer the best balance in characteristics, ensuring both immediate and long-term benefits for plant growth and soil health.

Sustainability of Using Basalt

The sustainability of using basalt in organic growing is a critical consideration. Basalt is abundant and widely available, making it a more sustainable option compared to other mineral fertilizers.

1. Low Environmental Impact: The extraction and processing of basalt generally have a lower environmental impact compared to synthetic fertilizers. It is a naturally occurring material that does not require extensive chemical processing.

2. Renewable Resource: Basalt is formed from volcanic activity, a natural and ongoing geological process, making it a renewable resource.

3. Reduced Chemical Dependency: By providing essential nutrients naturally, basalt reduces the need for chemical fertilizers, which can have harmful environmental effects such as water pollution and soil degradation.

Conclusion

Incorporating basalt into organic growing practices offers numerous benefits, from enhanced plant health and soil fertility to potential contributions towards CO2 reduction. The role of soil microbes and fungi in releasing the nutrients from basalt, as well as other minerals, underscores the importance of maintaining a healthy soil ecosystem. The sustainability of basalt, coupled with its positive environmental impacts, makes it an attractive option for organic farmers looking to improve their crop yields and soil health while mitigating their carbon footprint.

References

1. Almeida, E., de Souza, J., & Oliveira, R. (2020). "Impact of Basalt Rock Dust on Tomato Growth and Yield." Agronomy, 10(2), 210.

2. Beerling, D. J., Leake, J. R., & Long, S. P. (2018). "Farming with crops and rocks to address global climate, food, and soil security." Nature Communications, 9, 983.

3. Bolland, M. D. A., & Baker, M. J. (2000). "Basalt dust and phosphate fertiliser effects on some soil chemical properties and the early growth of clover and ryegrass." Australian Journal of Soil Research, 38(5), 923-934.

4. Jones, D. L., Willett, V. B., & Hodge, A. (2009). "Organic acid behavior in soils–misconceptions and knowledge gaps." Plant and Soil, 326(1-2), 213-224.

5. van Schöll, L., Smits, M. M., & Hoffland, E. (2008). "Ectomycorrhizal weathering of soil minerals." Nature Reviews Microbiology, 6(8), 611-620.

6. Lovelock, C. E., Posada, J., & Winter, K. (2012). "Coupling of sap flow, vapor pressure deficit, photosynthesis and water sources in tropical mangrove trees." Tree Physiology, 32(8), 822-834.

7. Edwards, A. C., Scalenghe, R., & Freppaz, M. (2017). "Soil formation in glacier forefields of the European Alps." Journal of Soils and Sediments, 17(3), 793-808.

8. Manning, D. A. C., Renforth, P., & Lopez-Capel, E. (2013). "Carbonate precipitation in artificial soils as a sink for atmospheric carbon dioxide." Applied Geochemistry, 32, 193-198.

9. Wheal, M. S., Fowles, T. O., & Palmer, L. T. (2008). "A cost-effective acid digestion method using closed polypropylene tubes for inductively coupled plasma optical emission spectrometry (ICP-OES) analysis of plant essential elements." Analytical Methods, 10(3), 402-410.

10. Gislason, S. R., Oelkers, E. H., Snorrason, Á., & Eiriksdottir, E. S. (2010). "Direct evidence of the feedback between climate and weathering." Earth and Planetary Science Letters, 294(3-4), 351-358.

11. Schuiling, R. D., & Krijgsman, P. (2006). "Enhanced weathering: an effective and cheap tool to sequester CO2." Climatic Change, 74(1-3), 349-354.

12. Leake, J. R., Johnson, D., Donnelly, D., Muckle, G. E., Boddy, L., & Read, D. J. (2010). "Networks of power and influence: the role of mycorrhizal mycelium in controlling plant communities and agroecosystem functioning." Canadian Journal of Botany, 82(8), 1016-1045.