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Compost

by Robert Hijmans
Published: Last Updated on
Compost

Compost is a type of organic matter that has been decomposed and recycled as a fertilizer and soil amendment. It is made by breaking down leaves, grass clippings, and other plant material, as well as food waste, into a rich, dark, crumbly substance that is high in nutrients and beneficial microbes.

It can be used in a variety of ways, including enriching soil, improving soil structure, and increasing water retention. It can also help to suppress diseases and pests, and reduce the need for chemical fertilizers and pesticides.

What is Composting?

Composting is a natural process that occurs when organic matter is broken down by microorganisms, such as bacteria and fungi. These organisms consume the organic matter and release nutrients and other beneficial substances, such as enzymes and hormones, back into the soil.

There are many benefits to composting, including:

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  • Reducing waste: Composting helps to reduce the amount of waste that ends up in landfills, which is good for the environment.
  • Improving soil structure: It helps to improve the structure of soil, making it more porous and able to hold water and nutrients.
  • Enhancing soil fertility: It is a natural source of nutrients that can help to improve soil fertility and support the growth of plants.
  • Reducing the need for chemical fertilizers: It can help to reduce the need for chemical fertilizers, which can have negative environmental impacts.
  • Suppressing diseases and pests: It can help to suppress diseases and pests that can damage plants.

History of Compost

The practice of composting, or the deliberate decomposition of organic matter to create a nutrient-rich soil amendment, has a long history dating back thousands of years. Here are some key points in the history of composting:

Ancient civilizations: The ancient Egyptians, Greeks, and Romans all used compost to improve soil fertility and support plant growth. The ancient Chinese philosopher Confucius is credited with the creation of the first composting system, which he called “the process of returning to the soil.”

History of Compost

Middle Ages: Composting became more widespread in Europe during the Middle Ages, with monasteries and other religious communities often serving as centers for composting knowledge and practice.

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18th and 19th centuries: Composting became more scientific in the 18th and 19th centuries, with the development of theories about plant nutrition and the role of organic matter in soil. Scientists and farmers began to experiment with different methods of composting and ways to improve the efficiency of the process.

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20th and 21st centuries: Composting has continued to evolve and become more widespread in the 20th and 21st centuries. The environmental movement of the 1970s brought renewed interest in composting as a way to reduce waste and improve soil health. Today, composting is a widely accepted and widely practiced method of soil improvement and waste management.

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In recent years, the use of compost has gained widespread recognition as a way to improve soil health, reduce waste, and combat climate change. Many cities and municipalities have implemented composting programs, and the use of compost in agriculture and horticulture has become more common.

Potential of compost

These statistics demonstrate the many benefits of compost and composting for soil health, plant growth, and the environment. Here are a few more statistics:

  • Composting can divert up to 30% of household waste from landfills.
  • The composting process can reduce the volume of organic waste by 50-80%.
  • The use of it can reduce the need for synthetic fertilizers and pesticides by providing a natural source of nutrients for plants.
  • In one study, the use of it was found to increase crop yields by up to 20%.
  • The use of it can reduce the need for irrigation by up to 50%, as it helps to improve soil structure and water retention.
  • The use of it can reduce the risk of soil erosion by up to 50%.
  • The use of it can reduce the amount of methane produced in landfills by up to 60%.
  • According to the Environmental Protection Agency (EPA), food waste accounts for about 21% of waste in the United States. As of 2030, the UK government intends to reduce food waste by 50%, Canada intends to divert 70% of waste, and Australia intends to divert 50% of waste from landfills, and composting is one of the strategies that is being used to achieve this goal.

What Can Be Composted?

It’s important to keep the balance of carbon and nitrogen-rich materials in the compost pile in mind when adding materials. A general rule of thumb is to aim for a mix of about two parts brown matter (carbon-rich materials) to one part green matter (nitrogen-rich materials). This will help to ensure that the compost decomposes properly and efficiently. There are many materials that can be composted, including:

  • Leaves: Fall leaves are a great source of carbon for the compost pile. They can be added whole or shredded to help them break down more quickly.
  • Grass clippings: Grass clippings are high in nitrogen and make a good source of green matter for the compost pile. They should be mixed with other materials to help prevent them from clumping together and forming a slimy mass.
  • Kitchen scraps: Fruits and vegetables, coffee grounds, tea bags, and eggshells are all good materials to add to a compost pile. These materials are high in nitrogen and help to speed up the decomposition process. Avoid adding meat, dairy products, or grease, as they can attract pests and produce odors.
  • Paper products: Shredded paper, cardboard, and newspaper can be added to the compost pile. These materials are high in carbon and help to balance out the nitrogen-rich materials in the pile. Avoid adding glossy paper, as it may contain chemicals that can be harmful to the composting process.
  • Garden waste: Prunings, weeds, and other plant debris can be composted. These materials are high in nitrogen and help to speed up the decomposition process.
  • Manure: Manure from herbivores, such as cows, horses, and goats, can be added to the compost pile. These materials are high in nitrogen and help to speed up the decomposition process. Avoid adding manure from carnivores, such as dogs and cats, as it may contain harmful bacteria.
  • Straw and hay: These materials can be added to the compost pile to provide carbon. They help to balance out the nitrogen-rich materials in the pile and provide structure to the compost.

What CAN’T Be Composted?

In general, it’s a good idea to avoid adding any materials to the compost pile that may contain toxins or pathogens, or that could potentially spread diseases or pests. There are a few materials that should not be added to a compost pile, including:

Meat, dairy products, and grease: These materials can attract pests and produce odors, and may also contain harmful bacteria that can contaminate the compost.

What CAN’T Be Composted

Diseased plants: Diseased plants can harbor diseases and pests that can spread to other plants, so it’s best to avoid adding them to the compost pile.

Invasive plants: Some plants, such as kudzu and Japanese honeysuckle, can spread aggressively and become invasive in certain areas. It’s best to avoid adding these plants to the compost pile to prevent them from spreading further.

Pet feces: Feces from carnivores, such as dogs and cats, may contain harmful bacteria and should not be added to the compost pile. Manure from herbivores, such as cows and horses, can be added to the compost pile, but it should be aged and well-composted to reduce the risk of bacterial contamination.

Diseased or chemically treated wood: Diseased or chemically treated wood may contain toxins or pathogens that can harm the composting process or contaminate the compost. It’s best to avoid adding these materials to the compost pile.

Glossy paper: Glossy paper may contain chemicals that can be harmful to the composting process. It’s best to avoid adding this type of paper to the compost pile.

Types of Compost

Each type of compost has its own unique characteristics and uses. Some types, such as vermicompost and composted manure, are known for their high nutrient content and are often used as fertilizers. Others, such as backyard compost and municipal compost, are used primarily to improve soil structure and fertility. There are several different types of compost, including:

Green compost: This type is made from fresh, green plant material, such as grass clippings, leaves, and vegetable waste. It is high in nitrogen, which is essential for plant growth.

Brown compost: This type is made from dry, brown plant material, such as twigs, branches, and fallen leaves. It is high in carbon, which helps to balance the nitrogen in green compost and helps to promote the decomposition process.

Backyard compost: It is made at home in a backyard compost bin or pile. It typically consists of yard and kitchen waste, and may include leaves, grass clippings, fruit and vegetable scraps, coffee grounds, and other organic materials.

Vermicompost: It’s made using worms to break down the organic matter. It is often made in a container, such as a plastic bin or wooden box, and is known for its high nutrient content and beneficial microbes.

Types of Compost

Municipal compost: This is made at a centralized facility using yard and kitchen waste collected from homes and businesses in a particular area.

Industrial compost: It is made using organic waste from industrial processes, such as food processing or manufacturing.

Compost tea: This is a liquid fertilizer made by steeping compost in water. It is often used to provide plants with a quick boost of nutrients.

Composted manure: This is made using manure from cows, horses, or other animals. It is often used as a natural fertilizer and soil amendment.

Bokashi compost: This type of compost is made using a special fermentation process that allows for the breakdown of food waste, including meat, dairy, and cooked foods. It can be used to enrich soil and improve plant growth.

Sheet composting: This method involves layering organic material, such as leaves, grass clippings, and other yard waste, directly onto the soil surface. The material is then allowed to decompose and enrich the soil over time.

Hot composting: This method involves the creation of a compost pile or bin that is designed to generate high temperatures through the action of microorganisms. Hot composting can be done on a small or large scale, and is often used to speed up the composting process.

It’s important to note that it should be made from a diverse range of organic materials in order to create a balanced, nutrient-rich product. Different materials will break down at different rates, so it’s important to mix and turn the compost regularly to ensure that it decomposes evenly.

Factors Affecting Compost

There are several factors that can affect the composting process and the quality of the resulting compost. By controlling these factors and maintaining a diverse mix of organic materials, it is possible to create high-quality compost for use in gardening and agriculture. These include:

  • Moisture: Composting requires a balance of moisture and oxygen. If the compost is too dry, it may not decompose properly. If it is too wet, it may become anaerobic, leading to the production of unpleasant odours.
  • Temperature: The temperature of the compost can affect the rate at which it decomposes. In general, higher temperatures will speed up the process, while lower temperatures will slow it down. Ideal composting temperatures range from 120 to 150 degrees Fahrenheit.
  • Carbon-to-nitrogen ratio: The balance of carbon (found in dry, brown materials) and nitrogen (found in green, wet materials) in the compost can affect the rate at which it decomposes. A balanced ratio of around 30:1 carbon to nitrogen is ideal for composting.
  • Oxygen: Oxygen is essential for the microorganisms that break down organic matter in the compost. Without sufficient oxygen, the compost may become anaerobic and produce unpleasant odours.
  • Size of organic matter: The size of the organic matter in the compost can affect how quickly it decomposes. Smaller pieces will decompose faster than larger ones.
  • Type of organic matter: Different types of organic matter decompose at different rates. For example, woody materials, such as twigs and branches, will take longer to decompose than softer materials, such as leaves and grass clippings.

Uses of Compost

Compost is a valuable resource for gardening and agriculture, as it helps to improve soil structure, fertility, and overall plant health. It is a sustainable and natural alternative to synthetic fertilizers and can be used in a variety of gardening and agricultural applications. Here are some specific ways in which it can be used and its effects:

Soil amendment: It can be mixed into soil to improve its structure, water-holding capacity, and nutrient content. It can also help to increase the population of beneficial microorganisms in the soil.

Mulching: It can be used as a mulch to cover the surface of soil around plants. It helps to retain moisture, suppress weeds, and regulate soil temperature.

Potting mix: Compost can be used as a component of potting mixes for container plants, providing them with a source of nutrients and improving the structure of the mix.

Uses of Compost

Lawn amendment: It can be spread over a lawn to improve the soil structure and nutrient content, leading to healthier grass growth.

Fertilizer: Compost tea, a liquid fertilizer made by steeping compost in water, can be applied to plants as a soil drench or foliar spray to provide them with a boost of nutrients.

Water conservation: It helps to improve soil structure, which can increase its ability to retain water. This can help to reduce the need for irrigation and water usage.

Carbon sequestration: Composting organic matter helps to reduce the amount of carbon dioxide in the atmosphere by capturing it in the soil. This process is known as carbon sequestration.

Waste reduction: Composting organic waste, such as food scraps and yard waste, helps to reduce the amount of waste sent to landfills. Landfills are a major source of methane, a potent greenhouse gas, so reducing waste can help to mitigate climate change.

Pest management: It can help to reduce the need for chemical pesticides by increasing the population of beneficial insects and microorganisms in the soil, which can help to control pests.

Improved plant health: Compost can help to improve the overall health and growth of plants by providing them with a source of nutrients and beneficial microorganisms. It can also help to improve soil structure, which can increase the plants’ ability to take up water and nutrients.

Drawbacks of Compost/Composting

There are a few potential disadvantages to composting:

Time and effort: Composting can require a significant amount of time and effort, especially if you are doing it on a small scale. It can be time-consuming to collect and process the organic material, and it can also be physically demanding to turn and maintain the compost pile.

Odor: If the compost pile is not managed properly, it can produce an unpleasant odor. This can be caused by a lack of oxygen, excess moisture, or an imbalance of carbon and nitrogen in the pile.

Pests: Compost piles can attract pests, such as rats, flies, and raccoons. This can be a problem if the compost pile is not managed properly or if it is located too close to a dwelling.

Space: Composting can require a significant amount of space, especially if you are doing it on a large scale. This can be an issue for those who live in urban areas or have limited outdoor space.

Cost: While composting can save money on fertilizers and soil amendments, it can also require an initial investment in equipment, such as compost bins or tumblers.

Limited material: Some materials, such as meat, dairy products, and bones, are not suitable for composting because they can attract pests or produce unpleasant odors. This can limit the types of material that can be added to a compost pile.

Risk of fire: Compost piles can produce heat as they decompose, which can increase the risk of fire if the pile is not managed properly.

Contamination: If non-organic materials, such as plastic or metal, are accidentally added to a compost pile, it can contaminate the compost and make it unusable.

Guide to Make Compost

Material

To make compost, you will need the following materials:

  • A compost bin or pile
  • Carbon-rich materials
  • Nitrogen-rich materials
  • Water
  • Oxygen

Steps

By following these steps, you can create nutrient-rich compost at home to use in your garden or landscaping. Here is a detailed guide to making compost at home:

Choose a suitable location: Select a location for your compost bin or pile that is convenient and easy to access, but not too close to your home or other buildings. The area should be well-drained and receive plenty of sunlight.

Guide to Make Compost

Gather materials: Collect organic material, such as food scraps, yard trimmings, and leaves, to add to your compost pile. A good balance of “brown” materials, such as leaves and twigs, and “green” materials, such as grass clippings and food scraps, will help to create the right conditions for decomposition. Aim for a ratio of about 30 parts carbon to 1 part nitrogen.

Set up a bin or pile: There are several options for setting up a compost bin or pile, including building a structure from wood or wire, using a purchased compost bin, or simply creating a pile on the ground. Whichever method you choose, be sure to create a structure that is large enough to hold the amount of material you will be composting and allows for proper air circulation.

Add the material: Begin by adding a layer of “brown” material, such as leaves or twigs, to the bottom of the compost bin or pile. Add layers of “green” material, such as food scraps and grass clippings, on top of the “brown” material. Mix the materials together as you go to ensure an even distribution of “browns” and “greens.”

Moisten and aerate: Moisten the material as you add it to the compost bin or pile to help speed up the decomposition process. Aerate the compost pile by turning it with a pitchfork or shovel every few weeks to ensure proper oxygen circulation.

Monitor the temperature: The compost pile should heat up as the decomposition process begins. This is a good sign that the composting process is working properly. If the pile becomes too hot, it may need to be cooled down by adding more “brown” material or watering it down. If the pile does not heat up, it may need to be stirred and moistened to encourage decomposition.

these steps, you can create nutrient-rich compost

Add water: Keep the compost pile moist, but not soggy. A good rule of thumb is to add water until the material is about as moist as a wrung-out sponge.

Harvest the compost: The compost is ready to use when it is dark and crumbly and has a rich, earthy smell. This can take anywhere from a few months to a year, depending on the size of the compost pile and the materials that are being composted.

Phases of composting

The length of each phase will depend on the size and composition of the compost pile or bin, as well as the environmental conditions. In general, the composting process can take several weeks to several months to complete. There are four main phases that occur during the composting process:Phases of composting

  • The mesophilic phase: This is the initial stage of decomposition, during which mesophilic bacteria break down the organic material. This phase occurs at temperatures between 20-45°C (68-113°F).
  • The thermophilic phase: This is the second stage of decomposition, during which thermophilic bacteria break down the organic material. This phase occurs at temperatures between 45-60°C (113-140°F).
  • The cooling phase: During this phase, the temperature of the compost pile or bin begins to decrease as the organic material continues to decompose.
  • The maturation phase: During this final phase, the compost continues to mature and stabilize. The compost is now ready to be used as a soil amendment.

Duration for Completion of Composting

Hot composting

Hot composting is a method of composting that generates heat through the decomposition process. This method is faster than cold composting and can produce finished compost in as little as a few weeks. To create a hot compost pile, you will need to create the right balance of carbon-rich and nitrogen-rich materials, as well as add water and oxygen to the mix. The decomposition process will generate heat, which will help to kill weed seeds and pathogens, and speed up the composting process.

Duration for Completion of Composting

The main advantage of hot composting is that it produces finished compost more quickly than cold composting. However, it requires more effort to maintain the right balance of materials and ensure that the compost pile stays moist and aerated.

Cold composting

Cold composting is a method of composting that does not generate heat through the decomposition process. This method is slower than hot composting and can take several months or even years to produce finished compost. Cold composting is a more passive process, and all you need to do is add the materials to the compost pile and let it decompose on its own.

The main advantage of cold composting is that it requires minimal effort and can be done with a variety of materials. However, it takes longer to produce finished compost and may not be as effective at killing weed seeds and pathogens as hot composting.

Removal of Contamination (Pathogens, Disease material & Weeds)

By following these steps, you can effectively remove pathogens from your compost and produce a safe and nutrient-rich soil amendment. It is important to note that compost should not be used on edible plants until it has fully matured and any pathogens have been killed off. Some ways to remove contamination from compost are:

Start with clean materials: One of the best ways to prevent pathogens from entering your compost is to start with clean materials. Avoid adding any diseased or moldy plant material, as well as any meat, dairy, or pet waste, to your compost pile. These materials can harbor pathogens and may not break down properly in the compost.

Chop or shred materials: Chopping or shredding your compost materials into small pieces will help to expose more surface area to the decomposition process and speed up the breakdown of the material. This can also help to kill off any pathogens that may be present.

Removal of Contamination (Pathogens, Disease material & Weeds)

Turn the compost pile regularly: Turning the compost pile regularly will help to mix the materials and expose them to oxygen, which is essential for the decomposition process. This will also help to kill off any pathogens that may be present.

Use a thermometer to monitor the temperature: Monitoring the temperature of your compost pile will help you to know if it is reaching the thermophilic range, which is between 45-60°C (113-140°F). This temperature range is necessary for killing off pathogens and weed seeds.

Use a hot composting method: By maintaining the right balance of materials and ensuring that the compost pile stays moist and aerated, you can generate heat through the decomposition process. This heat will help to kill pathogens and weed seeds.

Use a compost accelerator: Compost accelerators are products that contain beneficial bacteria and fungi that help to speed up the decomposition process and kill pathogens.

Add lime to the compost pile: Lime is a natural disinfectant that can help to kill pathogens in the compost. However, be careful not to add too much lime, as it can also kill the beneficial bacteria and fungi that are necessary for the decomposition process.

Age the compost: Allowing the compost to mature for a longer period of time will help to kill off any remaining pathogens.

Types of Compost Bins Can be Used

No matter which type of compost bin you choose, it’s important to follow proper composting techniques to ensure that the materials break down properly and produce high-quality compost. However, there are several types of compost bins that you can use to compost organic materials. Some options include:

Tumbler compost bin: This type of bin is a cylinder that you can rotate to mix the compost materials. Tumbler bins are convenient because they are easy to use and can produce compost faster than other types of bins.

Stationary compost bin: This type of bin is a stationary container that you fill with compost materials. You’ll need to use a pitchfork or other tool to mix the materials manually.

Worm compost bin: A worm compost bin uses worms to break down organic materials into compost. These bins are small and can be used indoors or outdoors.

Types of Compost Bins Can be Used

Compost pile: You can also create a compost pile by simply piling materials in an area of your yard. You’ll need to turn the pile regularly to ensure that it decomposes properly.

Bokashi composting system: A Bokashi composting system is a closed container that uses microorganisms to break down organic materials. It is a good option for people who live in apartments or have limited outdoor space.

Dual chamber compost bin: This type of bin has two chambers, one for actively decomposing materials and one for finished compost. You can use the finished compost while the other chamber continues to decompose.

Electric compost bin: An electric bin uses heat and moisture to speed up the decomposition process. These bins are often more expensive than other types of bins, but they can produce compost faster.

Garbage can compost bin: You can use a garbage can as a makeshift compost bin by drilling holes in the bottom and sides for ventilation. This is a cheap and easy option, but you’ll need to turn the materials manually to ensure that they decompose properly.

Rain barrel compost bin: A rain barrel compost bin is a container that collects rainwater and also serves as a compost bin. You can use the rainwater to water your garden and the compost to enrich the soil.

Kitchen compost bin: A kitchen compost bin is a small container that you can use to collect food scraps and other organic materials in your kitchen. These bins are convenient for people who don’t have a lot of outdoor space for composting.

When and How to Use Compost

It’s important to note that it is not a substitute for fertilizers, and you should still follow proper fertilization guidelines for your plants. It can, however, help to improve the overall health and vitality of your plants by enriching the soil and providing nutrients. Here are some guidelines for applying compost to your plants:

  • Determine when to apply the compost: The best time to apply it to your plants is in the spring or fall. In the spring, it will help to enrich the soil and provide nutrients for new growth. In the fall, the compost will help to prepare the soil for winter and provide nutrients for next year’s growth.When and How to Use Compost
  • Determine how much compost to apply: The amount of compost you apply to your plants will depend on the type of plant, the age of the plant, and the condition of the soil. As a general rule, you should apply about 1 inch of compost to the soil around the base of the plant. You can also incorporate it into the soil when planting new plants.
  • Determine how to apply the compost: There are several ways to apply compost to your plants. You can spread it on the soil around the base of the plant and gently incorporate it into the soil using a shovel or trowel. You can also mix it with potting soil when planting container plants.
  • Water the compost after applying: Water the compost well after applying it to your plants to help it settle into the soil. Be sure to water the plants thoroughly, as it will absorb moisture from the soil.
  • Slow release: When applying compost to your plants, it’s important to remember that it is a slow-release fertilization method. It may take several weeks or months for the it to fully break down and release nutrients into the soil.
  • Vegetables: Some plants, such as annuals and vegetables, have higher nutrient requirements and may benefit from more frequent applications of compost. You can apply it to these plants every few weeks or months, depending on the specific needs of the plant.
  • Perennial Plants: Perennial plants and trees generally have slower growth rates and may not require as much compost. You can apply it to these plants once or twice a year, in the spring and fall.
  • Recommended rates: When applying compost to your plants, be sure to follow the recommended application rates for the specific type of plant you are growing. Applying too much compost can lead to excess nutrients in the soil, which can be harmful to your plants.

If you are unsure of how much compost to apply to your plants, you can consult with a local garden center or extension office for guidance. They can help you determine the specific needs of your plants and provide recommendations for compost application rates.

Evidence on the Use of Compost

Here are a few examples of scientific research that provides evidence on the use of compost and its effects and importance:

A study published in the Journal of Environmental Quality found that the use of compost can significantly improve soil structure, nutrient availability, and plant growth. The study analyzed the effects of compost on soil and plant growth in several different agricultural systems and found that it improved soil structure, increased nutrient availability, and enhanced plant growth and yield.

Another study published in the journal Plant and Soil found that the use of compost can improve the growth and health of ornamental plants. The study examined the effects of compost on the growth and nutrient content of several ornamental plant species and found that it improved plant growth, nutrient content, and overall plant health.

A review published in the journal Environmental Science and Technology evaluated the potential of compost to reduce greenhouse gas emissions and support sustainable agriculture. The review found that the use of it can significantly reduce greenhouse gas emissions from agricultural systems, as well as improve soil health and crop productivity.

A study published in the journal Ecological Applications examined the effects of compost on soil carbon sequestration and soil quality in a grassland ecosystem. The study found that the use of it significantly increased soil carbon sequestration, improved soil structure, and enhanced the growth and diversity of native plants.

A study published in the journal Water, Air, and Soil Pollution examined the effects of compost on soil erosion and water retention in a degraded grassland ecosystem. The study found that the use of it significantly reduced soil erosion and increased water retention, leading to improved soil structure and plant growth.

A study published in the journal Agriculture, Ecosystems & Environment analyzed the effects of compost on soil health and plant growth in an organic farming system. The study found that the use of it significantly improved soil structure, nutrient availability, and plant growth, leading to increased crop yields and reduced fertilizer and pesticide use.

A review published in the journal Environmental Management examined the role of compost in the sustainable management of agricultural and urban landscapes.

Conclusion

Composting is a sustainable and effective way to reduce waste and improve soil health. By breaking down organic materials and returning them to the soil, compost helps to nourish plants and reduce the need for synthetic fertilizers. It is an easy and cost-effective way for individuals and communities to make a positive impact on the environment and support local agriculture.

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