Building soil organic matter (SOM) will improve plant available nutrients in the following ways:

• Increased nutrient storage: SOM can store a large pool of essential plant nutrients, such as nitrogen, phosphorus, and potassium. As SOM decomposes, these nutrients are released into the soil in a form that is readily available to plants.
• Improved nutrient retention: SOM can help to retain nutrients in the soil, preventing them from leaching away into groundwater or being lost to the atmosphere. This is because SOM has a high cation exchange capacity (CEC), which means that it can hold onto positively charged ions, such as ammonium (NH₄⁺) and potassium (K⁺).
• Enhanced nutrient availability: SOM can improve the availability of nutrients to plants by chelating them. Chelation is a process in which metal ions are bound to organic molecules, making them more soluble and available to plant roots.
• Increased microbial activity: SOM provides a food source for soil microorganisms, which play an important role in nutrient cycling. As microorganisms decompose SOM, they release nutrients into the soil and also produce organic substances that can improve nutrient availability to plants.

Importance of soil organic matter in plant nutrition:

SOM is essential for plant nutrition because it provides a source of essential nutrients and improves the availability of those nutrients to plants. SOM also helps to improve soil structure, water infiltration, and water holding capacity, all of which are important factors for plant growth.

In addition, SOM plays a role in plant defense against pests and diseases. SOM can suppress the growth of harmful pathogens and attract beneficial organisms, such as mycorrhizal fungi, which can help to protect plants from disease and improve nutrient uptake.

Overall, building soil organic matter is one of the best things you can do to improve plant nutrition and grow healthy, productive plants.

Here are some tips for building soil organic matter:

• Add organic matter to the soil regularly, such as compost, manure, or mulches.
• Cover the soil with a living cover crop whenever possible.
• Reduce tillage to minimize disturbance to the soil and its microbial community.
• Adopt sustainable farming practices that promote soil health, such as crop rotation and cover cropping.

By building soil organic matter, you can create a healthy and productive soil environment for your plants to thrive in.

Dr Murtadha Shukur thank you for your contribution to the discussion

Soil organic matter, its stable components and its transient components can strongly improve nutrient availability and acquisition by higher plants. Soil organic matter also strongly affects nutrient storage and its availability in soils. 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 structure plays an important role in determining the amounts of nutrients that are available for uptake by roots as well as growth of roots laterally and down the profile. Location of roots and the properties of the surrounding microenvironment influence nutrient uptake. Soil pH affects the availability of nutrients to plants. In acid soils (pH is low) calcium and magnesium become more available to plants, whereas the micronutrients iron, aluminum and manganese become soluble and can reach levels toxic to plants. Adding organic matter improves soils high in clay or sand. Soils high in OM retain more moisture, have a crumbly structure that resists soil compaction, and contain a reservoir of nutrients that are slowly released over time. OM improves soil aeration, water drainage, root growth, and biological activity. Increasing levels of organic matter aid in soil structure, water-holding capacity, nutrient mineralization, biological activity, and water and air infiltration rates. Organic matter drives nutrient availability in the soil, improves nutrient retention in soils and water holding capacity. It also promotes aggregate formation. It accumulates via inputs from plants, both from litter on the surface and root turnover in the soil. Organic matter includes any plant or animal material that returns to the soil and goes through the decomposition process. In addition to providing nutrients and habitat to organisms living in the soil, organic matter also binds soil particles into aggregates and improves the water holding capacity of soil. 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. Organic matter contributes to nutrient retention and turnover, soil structure, moisture retention and availability, degradation of pollutants, and carbon sequestration.

Organic Matter (OM) plays a significant role in crop production and soil health through improving soil physical, chemical and biological functions. Increasing levels of organic matter aids in soil structure, water-holding capacity, nutrient mineralization, biological activity, and water and air infiltration rates. The five key functions of OM are described in the attached file.

Best regards,

Chibeba

Dr Amaral Chibeba thank you for your contribution to the discussion