Organic matter

Things that once lived turn into organic matter.

This comes from dead plants and animals. It also comes from animal waste.

Tiny living things like fungi break it down. They turn it into soil. This process helps the earth move nutrients around.

This matter helps the ground hold water. It also helps plants grow by giving them food. This is very important for farms.

In the woods, leaves fall to the ground. They rot and become part of the soil. This makes the soil stay together.

It is amazing how old things help new things grow.

Organic matter is made of things that once lived. It comes from dead plants and animals. It also comes from animal waste.

Tiny living things like fungi and bacteria help break it down. This set of steps is called decomposition. These small life forms turn the matter into nutrients. Nutrients are the food that plants need to grow. This matter also helps soil hold water. It helps the soil stick together too. This allows tiny bacteria to work more easily.

When organic matter breaks down a lot, it becomes humus. Humus is a stable substance. It stays in the soil for a long time. You can make more humus by adding compost. Compost is organic material that has already decayed. You can also add green manure. This is plant material grown just to be put into the soil. This gives microbes more power to work. This helps plants survive and grow well. Organic matter is very important for farms and nature.

Organic matter is a huge source of carbon-based compounds found all over our world. It exists in the land, in the water, and even in man-made places. This matter comes from the remains of living things like plants and animals. It also comes from animal waste, which is often called feces. Sometimes, organic molecules are made by chemical reactions that do not even need life. These materials are very important because they move nutrients through the environment. They also help the surface of our planet hold onto water.

There is a specific way this matter works in nature through a process called decomposition. First, living things release organic material into their surroundings. They might shed leaves and roots or leave behind waste. After these things die, tiny living things like bacteria and fungi go to work. These microbes use enzymes to break the biological molecules apart. This step-by-step breakdown turns the remains into smaller pieces. Sometimes, these small pieces join back together to form even larger molecules. This cycle keeps nutrients moving so other living things can eat.

Scientists have studied these natural cycles for a long time. In 1926, a researcher named Löhnis discovered something called the priming effect. He studied how adding fresh plant waste to soil changed how it worked. Later, in 1953, a person named Bingeman gave this discovery its official name. Before that, people used different names like "extra N" or "added nitrogen interaction." Even though it was known for a long time, many people ignored the idea until the 1980s or 1990s. Today, we know this effect happens in most plant and soil systems.

Organic matter is made of many different parts with specific amounts. By weight, it is usually 45% to 55% carbon. It also contains 35% to 45% oxygen, along with small amounts of hydrogen and nitrogen. In the soil, when organic matter breaks down completely, it becomes humus. Humus is a stable substance that resists breaking down further. This substance helps soil stick together so microscopic bacteria can work easily. It also helps plants grow by releasing nutrients slowly over time. You can even make more humus by adding compost or green manure to the ground.

You can see how organic matter works by looking at a forest floor. When leaves and wood fall, they become organic material. As they decay and you can no longer recognize them, they become soil organic matter. This is just like how a compost pile works in a garden. You take old plant waste and let it turn into rich soil. This same process happens in the water, too. In lakes and oceans, organic matter can be dissolved or stay in tiny floating pieces. This helps keep the entire planet's ecosystem healthy and strong.

Organic matter is a massive source of carbon-based compounds found in many environments. It exists in terrestrial, aquatic, and even engineered systems. This matter is composed of organic compounds that originate from the remains of plants and animals. It also includes animal feces. Interestingly, organic molecules can also be created through chemical reactions that do not involve life at all. Organic matter is essential because it moves nutrients through the environment. It also plays a vital role in how the planet's surface retains water.

The formation of organic matter follows a specific cycle. Living organisms secrete or excrete organic material into their surroundings. They also shed parts like leaves and roots. When these organisms die, their bodies are broken down by the action of bacteria and fungi. These microbes use enzymatic catalysis to disintegrate biological molecules. Sometimes, the smaller pieces undergo polymerization. This means different parts of the broken-down matter join together to form much larger molecules. The final composition of natural organic matter depends on its origin, its age, and its environment.

In soil, organic matter behaves in very specific ways. When plant and animal remains fall to the forest floor, they are called organic material. As this material decays until it is no longer recognizable, it becomes soil organic matter. If it breaks down into a stable substance that resists further decay, it is called humus. Humus is very important for plant growth. It improves the soil's ability to hold water and nutrients. It also helps the soil stick together. This allows nematodes and microscopic bacteria to decay nutrients more easily.

Scientists have studied how adding new material affects this cycle. This phenomenon is called the priming effect. It involves intense changes in the natural turnover of soil organic matter. This happens when there are pulsed or continuous changes in the input of fresh organic matter (FOM). Adding FOM can trigger an acceleration of mineralization. This occurs because specialized microorganisms grow quickly to eat the new material. This process can be positive or negative. A positive priming effect accelerates mineralization. A negative effect leads to immobilization, making nitrogen unavailable.

The history of the priming effect shows how scientific ideas evolve. A researcher named Löhnis first discovered this phenomenon in 1926. He studied how green manure decomposition affected legume plants. In 1953, Bingeman gave the discovery the official name "priming effect." Before this, people used terms like "added nitrogen interaction" or "extra N." Many scientists disregarded the concept until the 1980s and 1990s. We now know that the priming effect is a common occurrence in most plant and soil systems. It can happen almost instantaneously after a substance is added to the soil.

Organic matter is a complex and heterogeneous substance. By weight, it is typically 45% to 55% carbon. It also contains 35% to 45% oxygen, 3% to 5% hydrogen, and 1% to 4% nitrogen. The molecular weights of these compounds vary drastically. They can range from 200 to 20,000 amu. Up to one-third of the carbon is found in aromatic compounds. These consist of six-membered rings of carbon atoms. These rings are very stable due to resonance stabilization. This stability makes them quite challenging to break down.

Organic matter also functions differently in aquatic environments. In water, it is divided into two main components. The first is dissolved organic matter (DOM). This is measured as colored dissolved organic matter (CDOM) or dissolved organic carbon (DOC). The second is particulate organic matter (POM). Scientists differentiate them using a filter. Anything that can pass through a 0.45 micrometer filter is considered DOM. Anything that cannot pass through is considered POM. This distinction is important for understanding how matter moves through water systems.