Brown Manure: Purpose, Process, Examples and Benefits

So, you’ve recently discovered there are such things as “brown manure” and “green manure” that aren’t referring to different colors and types of animal poop, and you’re curious what they are… well, so were we! 

You’ll love what we found out because it’s great for your crops and way more pleasant to handle than animal poo of any color.

What is brown manure?

Brown manure consists of organic materials like pine needles, twigs, tree bark, and leaves. It is used for the “no-till” version of green manuring (tilling live organic materials into the soil). Sometimes, a non-harmful herbicide is used to kill green manure and turn it brown.

Read on below and learn more about brown manure, including what it’s for, the process of making and using it, and more!

What Is the Difference Between Green Manure and Brown Manure?

The first major difference between green manure and brown manure is that the green kind is often living (hence it is green), and the brown kind is made up of dead stuff (which explains why it’s brown).

The second significant difference is that brown manure is applied to the top of the soil, or left laying where it is killed, and possibly lightly mixed into the surface while green manure is copiously mixed down into the soil via a tiller, discs, or plow.

Other differences include what types of organic material they consist of, how often they should be applied, and what benefits they have to offer specific types of crops.

Let’s break the differences between green and brown manure down a bit further in the next sections:

Green Manure

Green manuring is the act of leaving extra crops growing, with or without your normal crops, in the garden, or in the field, to till them and feed vital nutrients back into the soil.

A few of the best cover crops to use for green manure include:

  • Alfalfa
  • Beans
  • Clover
  • Peas
  • Rye
  • Vetch
  • Wheat
  • Grasses

Brown Manure

Brown manuring is the creation/collection and application of “brown” organic material, onto your garden or field. It is applied to the top of the soil, however, not tilled into the ground like green manure.

Some of the best materials for brown manure are:

  • Tree bark
  • Twigs and broken branches
  • Wood chips
  • Leaves
  • Sunflowers
  • Pine needles

What Is Brown Manuring in Rice?

Brown manuring in rice is similar to green manuring in rice (the act of growing a secondary crop like Sesbania spp. alongside the rice, and tilling it into the soil after the rice hits a certain growth stage, to provide water retention, and nutrients.

Brown manuring in rice, however, doesn’t involve tilling the cover crop into the ground. Instead, the green manure is left lying on the ground, turning it into brown manure and slowly feeds the growing crops.

Further, brown manuring in rice doesn’t have to require an actively growing cover crop, rather all you need to do is collect and distribute fresh organic matter to the garden or field where the rice is growing.

Is Brown Manure the Same as a Cover Crop?

Brown manure is used in an extremely similar way to cover crops, as is green manure. However, the difference is that while cover crops, essential living green manure, is that brown manure is already dead, dried/drying, and decomposed/decomposing when it is applied to the garden or field your crops are growing in.

What Is the Purpose of Brown Manure?

Brown manure is used for reintroducing decomposed and decomposing organic materials back into the garden or field from whence they came, as well as the leftover nutrients they carry. It may also be applied to help increase water retention levels of the soil, or as protection from pests or harsh temperatures.

Brown Manure Pros and Cons

As with any gardening/farming technique, there are a few pros and cons that you should consider before simply deciding whether brown manure is right for your farm or garden or not:

Benefits of Brown Manure

When it comes right down to it, there are quite a few benefits to brown manure:

  • Reintroduces wasted nutrients into the soil
  • Helps keep the yard and garden stay cleaned up
  • Costs virtually nothing
  • Increases good carbon in the soil
  • Eco-friendly weed control
  • Prevents wind erosion of the soil
  • Raises water retention in the soil
  • Offers protection from harsh weather
  • Prevents some insects
  • Doesn’t necessarily require being grown

Brown Manure Drawbacks

The most significant drawbacks to brown manure include:

  • Collecting It takes time, as does waiting for it to break down
  • Not all types of wood are good for brown manure
  • Not all crops benefit from brown manure

Brown Manure Examples

There are two types of brown manure examples; the organic materials that make it up, and the practice of applying brown manure in gardens and fields.

The most common materials used in brown manure are parts of trees, like bark and twigs, as well as leaves, pine needles, dried plants, and more. In some cases, cardboard may even be considered brown manure.

Applying brown manure is commonly seen in between crop rows, through garden trails, and around the base of plants. The brown manure acts as pest control and weed control, offers better water retention, and slowly releases nutrients back into the soil.

What Types of Crops Benefit From Brown Manure?

Legume, rice, canola, barley, wheat, and crops that lack particular nutrients (for whatever reasons) benefit from the act of brown manuring (killing green manure “crops” at the flowering stage, and turning them into “brown” manure), as it provides a boost of much-needed carbon and nutrients right when your crops need it the most.

What Herbicides Are Used With Brown Manuring?

Pendimethalin is one of the most successful herbicides to use with brown manuring. Selective herbicides are often used on green manure plants, in order to pull off brown manure. This allows the targeted living organic materials to become brown manure, while any currently growing crops are left unharmed. 

Are Brown Manure Crops Tilled Under After Herbicide Is Applied?

Brown manure crops are not typically tilled under after herbicide is applied, rather they are left to lie on the surface of the ground and decompose in place. In this manner, they offer pest protection, weed control, increased moisture in the soil, and a slow release of nutrients and carbon. 

Can the Brown Manuring Technique Be Used for Home Gardens?

Brown manuring can and is used for home gardens on a regular basis. Applying brown manure to the base of plants, and in the trails between garden rows, for example, is a great weed suppression technique. It also helps your garden stay moister, longer.

How Do You Know Whether To Use Green Manure or Brown Manure?

Green manure is best if you want to raise the level of nutrients in the soil, increase its health, or actively feed growing crops. Brown manure is better for weed prevention, protection from harsh weather, and retaining moisture in the soil.

Conclusion

Brown manure is a great way to kill weeds, protect crops from some pests, prevent new growth, and improve the water retention and overall health of your garden or field’s soil at the same time.

If you’re looking for a natural manuring technique to help restore the vitality of your garden or fields, green manure may be of your interest as well!

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