什么是堆肥？如何开始呢

From VOA Learning English, this is the Health & Lifestyle report.

Improvements to the world around us can sometimes result from actions taken by individuals. For example, take composting.

Compost is organic material that, when added to soil, can help plants grow. And there are many different kinds of organic material. Food waste, grass cuttings and other plant remains make up more than 28 percent of what Americans throw away. That information comes from the United States Environmental Protection Agency (EPA).

The EPA website tells how composting helps the environment. It says:

•Composting helps to keep soil healthy.
•It reduces the need for chemical fertilizers.
•Composting can help the production of good bacteria and fungi, which break down organic matter.
•Composting also reduces methane gas emissions from landfills. Studies have linked methane to rising temperatures in Earth's atmosphere.
Yet many Americans do not compost their food and plant waste.

In 2014, a survey of 2,000 Americans found that 72 percent of those questioned did not compost. However, 67 percent said they would do so if it were easier. The National Waste & Recycling Association paid for that study.

There are only a few U.S. communities that have passed laws restricting some organic material from garbage collection. Two examples are New York City and San Francisco, California. And five months ago, the state of Vermont banned the collection of food waste.

While the numbers of Americans composting remains low, some people are trying to increase the number of composters. They often talk about landfills releasing methane into the atmosphere.

"Garbage piles contribute to global warming. And so there's a lot of methane that's released. And from everything that scientists know that that's contributing to the warming of the planet which is not a good thing."

That is Katie Ablard of Maryland. She has been composting for 15 years and enjoys teaching others.

"Instead of putting our food waste into the garbage, we're putting our food waste into the compost pile. And in the compost pile in our backyard, within a couple of months that breaks down and it breaks down and turns into really, really fertile soil."

Some countries are much better at making compost than the United States.

In a 2019 report, the World Economic Forum found that South Korea recycled 95 percent of its food waste. But this did not happen overnight. In 1995, South Koreans only recycled two percent of their food waste.

Back in 2013, the Yale School of the Environment published a paper on composting around the world. At that time, researchers found that Norway, Sweden, the Netherlands, Denmark, Switzerland, Belgium, Austria, and Germany sent less than three percent of their food waste to landfills.

How to start outdoor composting

If you want to make compost, there are some things to know. The EPA website says all composting requires three basic ingredients:

1.Brown material -- such as dead leaves and tress branches
2.Green material -- such as grass cuttings and vegetable waste
3.Water
When composting outdoors the EPA offers these suggestions.

Choose a dry area for your compost pile. The area should receive very little sunshine. Make sure there is no standing water on the ground.

Next, add green and brown materials, in equal amounts, as they are collected. Try to break down larger pieces. And add water if the brown materials are too dry.

If your area gets a lot of rain, cover up the compost pile. And make sure you can easily get to the area, but animals cannot. When the waste material at the bottom is dark and rich in color, your compost is ready to use.

Here is another piece of advice. Mix or stir the compost often. This adds air to keep it light, or as Katie says, fluffy. What you do not want, she warns, is for the material to get hard or compacted.

"I think of it as stirring and turning the compost. And getting it so it's kind of fluffy so that the soil is kind of light and airy and not compacted. You don't want it hard and compacted. (So, you need air flow?) You do need air flow, yeah."

Indoor composting

The EPA website says that if you do not have space for a compost pile outside your home, you can compost materials indoors. But you may need a special container for that.

The site says to be careful of what you throw in. A properly managed compost bin will not attract animals and will not smell bad. And your indoor compost should be ready in two to five weeks.

Katie Ablard says composting is great for the environment. But she says it gives her a smaller, but still very important prize.

"Twice a year I'm able to pull out the soil that the worms and the other bugs and insects have created by breaking down the food waste. And that soil or compost then I use in our garden. And so, the soil in our community garden is very rich and very healthy and has consistently been good soil for growing vegetables. So, it's instead of using chemical fertilizers and it's instead of using other products that might help things grow, but we can just use the compost!"

And that's the Health & Lifestyle report. I'm Anna Matteo.

Do you compost? Tell us about composting where you live in the Comments Section.

Anna Matteo reported this story for VOA Learning English. George Grow was the editor.