Organic matter is a complex mixture of dead plant and animal residues, as well as the products of their decomposition by soil microorganisms. It is a vital component of healthy soils, playing a key role in soil fertility, structure, and water retention.

Why is organic matter so important?

Organic matter is important for a number of reasons:

• It provides a source of nutrients for plants. As organic matter decomposes, it releases essential nutrients, such as nitrogen, phosphorus, and potassium, into the soil.
• It improves soil structure. Organic matter helps to bind soil particles together, creating aggregates that improve drainage and aeration. This makes it easier for plant roots to grow and access nutrients.
• It increases water retention. Organic matter acts like a sponge, absorbing and holding water. This helps to reduce drought stress and improve plant growth.
• It supports soil biodiversity. Organic matter provides a food source and habitat for a wide variety of soil organisms, including bacteria, fungi, and earthworms. These organisms play an important role in nutrient cycling and soil health.

Role of organic matter in the soil to improve nutrient availability

Organic matter plays a vital role in improving nutrient availability in the soil in a number of ways:

• It acts as a storehouse of nutrients. Organic matter can hold up to 95% of the total nitrogen in the soil, and significant amounts of other nutrients, such as phosphorus and sulfur.
• It releases nutrients slowly over time. As organic matter decomposes, it releases nutrients into the soil in a form that is readily available to plants. This helps to ensure that plants have a steady supply of nutrients throughout the growing season.
• It improves the cation exchange capacity of the soil. The cation exchange capacity (CEC) is a measure of the soil's ability to hold positively charged ions, such as calcium, magnesium, and potassium. Organic matter has a high CEC, which means that it can hold a large amount of nutrients in a form that is available to plants.
• It reduces nutrient leaching. Nutrient leaching is the loss of nutrients from the soil due to water movement. Organic matter helps to reduce nutrient leaching by binding nutrients to soil particles and making them less susceptible to being washed away.

Overall, organic matter is essential for improving nutrient availability in the soil. It acts as a storehouse of nutrients, releases them slowly over time, improves the cation exchange capacity of the soil, and reduces nutrient leaching.

How to increase organic matter levels in the soil

There are a number of ways to increase organic matter levels in the soil, including:

• Adding compost or manure. Compost and manure are excellent sources of organic matter. They can be added to the soil as a topdressing or mixed in with the soil before planting.
• Leaving crop residues in the field. Crop residues, such as cornstalks and soybean stubble, can be left in the field after harvest to decompose and add organic matter to the soil.
• Planting cover crops. Cover crops are plants that are grown to protect and improve the soil. They can be planted between rows of crops or after harvest. Cover crops add organic matter to the soil and also help to improve soil structure and water retention.

By following these practices, farmers and gardeners can help to increase organic matter levels in their soil, which will improve nutrient availability and lead to healthier plants and higher yields.

Dr Murtadha Shukur thank you for your contribution to the discussion

Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have come from the feces and remains of organisms such as plants and animals.Soil organic matter is a primary source of carbon (C) which gives energy and nutrients to soil organisms. This supports soil functionality because it improves the activity of microorganisms in the soil and it can enhance biodiversity. Crops are better able to withstand drought when infiltration and water holding capacity increase. Organic matter may bind pesticides, making them less active. Soils managed for organic matter may suppress disease organisms, which could reduce pesticide needs. Organic matter retains plant nutrients and prevents them leaching to deeper soil layers. Microorganisms are responsible for the mineralization and immobilization of N, P and S through the decomposition of organic matter. Soil organic matter significantly improves the soil's capacity to store and supply essential nutrients, and to retain toxic elements. It allows the soil to cope with changes in soil acidity, and helps soil minerals to decompose faster. It increases the water holding capacity of the soil, particularly in sandy soils. It improves aeration and infiltration in heavy soils. It serves as an important source of certain plant of food element. Precise nutrient availability and fertilizer management are essential for crop productivity. Accurate estimation of the nutrient availability in the soil will help in increasing productivity and reducing the leaching of excess nutrients. Organic matter contributes to nutrient retention and turnover, soil structure, moisture retention and availability, degradation of pollutants, and carbon sequestration. Factors that affect the availability of soil nutrients include leaching, soil erosion, soil pH, denitrification, volatilization, nitrogen immobilization and crop nutrient uptake. This article will discuss some of these factors.Nutrient availability in soil is influenced by many, often interrelated, factors. These include the parental rock material, particle size, humus and water content, pH, aeration, temperature, root surface area, the rhizoflora, and mycorrhizal development. Soil organic matter (SOM) plays important roles in carbon storage, aggregate formation, plant nutrient supply and retention, and the immobilization and mobilization of metals.