Understanding the Role of Soil Microbes with Laura Decker

Summary

Laura Decker, from Prolific Earth Sciences, discusses the importance of soil microbes and their crucial role in sustainable agriculture. She explains how conventional farming practices using chemical fertilizers and pesticides have disrupted the symbiotic relationship between plants and microbes, leading to soil degradation. Decker emphasizes the need to rebuild a balanced microbial community by reducing chemical inputs and fostering conditions for microbes to thrive. This includes using cover crops, implementing microbial inputs, and adopting bio-stimulants that enhance soil structure and nutrient availability. By understanding the significance of a healthy soil microbiome, farmers can reduce input costs, increase crop resilience, and potentially earn carbon credits, making farming more profitable and environmentally sustainable.

Takeaways

• 🌱 Microbes have a symbiotic relationship with plants, feeding each other and contributing to soil health.
• 🚜 Conventional agriculture with chemical fertilizers and pesticides has disrupted the natural microbial communities in the soil.
• 💪 Healthy soil relies on diverse microbial communities for plant immunity, nutrient cycling, soil structure, and carbon sequestration.
• 🌳 Microbes help build soil structure by secreting sticky substances that bind soil particles together, creating pockets for air and water.
• 🍽️ Microbes create both fresh and stable soil organic carbon (food stores) for plants and themselves.
• 🌻 A balanced, diverse microbial community is key for optimal plant growth, immunity, and weed control.
• 🚫 Direct microbial inputs may not work if the soil conditions are not suitable for microbial growth.
• 🌏 Microbial communities can vary widely based on soil composition, climate, and region.
• 📈 Monitoring changes in microbial biomass over time is more important than the absolute number.
• 🔬 The microBIOMETER helps farmers and growers assess their soil microbial health and the impact of their practices.

Q & A

What is the main topic of this presentation?

The main topic of this presentation is the importance of soil microbes and their role in agriculture, with a particular focus on how they contribute to soil health and plant growth.

What are the negative effects of conventional agriculture on soil microbes?

The extensive use of chemical fertilizers, herbicides, and pesticides in conventional agriculture has led to a decline in soil microbe populations. The chemical fertilizers provide nutrients in a readily available form, reducing the symbiotic relationship between plants and microbes, and the herbicides and pesticides can directly harm the microbes.

How do microbes contribute to plant health and soil structure?

Microbes provide immunity to plants against pathogens, help plants acquire essential nutrients and minerals, digest plant litter and convert it into soil organic carbon, communicate soil conditions to plants, and build soil structure through the secretion of sticky substances that bind soil particles together.

What is the relationship between root structure and microbes?

Plant roots serve as a means of communication between plants and microbes. When plants are fed chemical fertilizers, they have a decreased need for microbes, leading to reduced root structure. A diminished root structure then creates a vicious cycle, as fewer roots mean less decomposition and less soil organic carbon for microbes to thrive.

What is the importance of microbial diversity in soil?

Microbial diversity is crucial for a healthy soil ecosystem. Different microbes have different functions, and a diverse microbial community can provide a wider range of benefits to plants, including micronutrients, immune responses, and resilience to pathogens and environmental stresses.

How do microbes build soil structure?

Microbes secrete a sticky substance called EPS (extracellular polymeric substances) that binds to soil particles, creating small cavities or "caves" around them. These caves can hold oxygen, water, and other microbes, forming soil aggregates. As microbes die, their bodies become soil organic carbon, further contributing to soil structure.

What is the difference between fresh and stable soil organic carbon?

Fresh soil organic carbon is readily available for microbes and plants to consume, similar to food in a refrigerator. Stable soil organic carbon is more complex and needs to be broken down further, like food in a freezer that needs to be defrosted and cooked before it can be consumed.

What is the purpose of priming meals in soil?

Priming meals, such as compostees or other inputs with sugars and microbes, can provide a burst of readily available food for soil microbes. However, if the existing soil cannot sustain microbial life, these microbes will eventually die off when the priming meal is consumed, leading to a temporary boost in microbial activity.

How can microbial inputs like mycorrhizal fungi or compostees affect soil microbial communities?

The success of direct microbial inputs, such as mycorrhizal fungi or compostees, can vary. If introduced to soil that cannot support microbial life, the added microbes may not survive. However, research is ongoing to understand how microbial populations vary across different locations and how to effectively introduce beneficial microbes.

What is the purpose of the microBIOMETER product mentioned in the presentation?

The microBIOMETER is a product developed by the presenter's company, Prolific Earth Sciences, that allows farmers and growers to test their soil microbial biomass in real-time, over time. This enables them to assess the impact of various practices and products on their soil microbiome and make informed decisions to improve soil health.