What is HUMUS?

Summary

Soil's top layer, rich in humus, is crucial for plant growth. Humus, formed from organic matter by microbes, acts as soil glue, binding particles and preventing erosion. It's a complex substance with remarkable properties, including water and nutrient retention, enhancing soil structure, and buffering against toxins. Despite its stability, humus can be lost through soil disturbance. To maintain healthy soil, it's vital to incorporate organic matter and minimize soil disruption.

Takeaways

• 🌱 Soil is defined as the upper layer of earth where plants grow, typically consisting of organic debris, clay, and mineral particles.
• 🌿 'Humus' is a vital component of topsoil, found mainly in the top 10 to 30 centimeters, acting as a binding agent for soil particles.
• 🔬 The formation of humus is complex and not fully understood, but it begins with the breakdown of organic matter by microbes.
• 🌐 Humus is not a single compound but a collection of organic polymers formed from molecules that can't be further broken down by microbes.
• 💧 Humus has excellent soil buffering properties and contributes to soil structure, helping to retain water and nutrients.
• 🌾 The spongy nature of humus molecules allows them to hold a large amount of water and nutrients, improving soil resistance to drought and nutrient leaching.
• 🕰 Humus is incredibly stable, with some compounds lasting for thousands of years in undisturbed soil.
• 🚫 Soil disturbance, such as digging, leads to the loss of humus, which is not easily replaced by nutrient substitutes.
• 🌱 Humic acids, part of humus, are excellent at transporting nutrients from the soil to plants, preventing leaching.
• 🌱 To enhance soil health, incorporating humus is essential, and this can be achieved by adding organic matter through mulching and minimizing soil disturbance.

Q & A

What does the English dictionary define soil as?

Soil is defined as the upper layer of earth in which plants grow, typically consisting of organic debris, clay, and mineral particles.

What is the role of humus in soil?

Humus acts as soil glue, binding particles together and preventing them from washing or blowing away.

How deep is the layer of soil where humus is mainly found?

Humus is mainly found in the top ten to thirty centimeters of soil.

What is the significance of humus formation in soil chemistry?

The formation of humus is one of the least understood and most intriguing aspects of soil chemistry.

What is the starting point for the formation of humic substances?

The formation of humic substances begins with organic matter, which is broken down by microbes into simple molecules.

How do the remaining simple molecules contribute to the formation of humus?

The remaining simple molecules that cannot be broken down combine to form chains of organic polymers, leading to the initial stages of humus.

What are the benefits of humus for soil buffering properties?

Humus provides soil buffering properties by absorbing certain toxic elements and holding onto nutrients and water.

How does the structure of humus molecules contribute to soil health?

Humus molecules are spongy in nature, allowing them to hold an incredible amount of water and nutrients, making soil more resistant to drought and leaching.

How long do humus compounds last in undisturbed soil?

Some humus compounds can last for thousands of years in undisturbed soil.

Why is it important not to disturb the soil unnecessarily?

Disturbing the soil can lead to the loss of humus, which is not easily replaced by nutrient substitutes and contributes to soil degradation.

How do humic acids help in transporting nutrients from the soil to the plant?

Humic acids are good at transporting a whole spectrum of nutrients from the soil to the plant by holding onto these nutrients, preventing them from leaching out.

What is a recommended method to incorporate humus into the soil?

Mulching is a great way to get organic matter into the soil, which is the raw building blocks of humus.