What happens if soil has too much organic matter?

Soil organic matter is essential for a healthy soil, but it is possible to have too much of a good thing. If a soil has too much organic matter, it can become waterlogged and anaerobic, which can lead to a number of problems, including:

• Reduced plant growth: Plants need oxygen to survive, and anaerobic conditions can suffocate their roots.
• Increased risk of pests and diseases: Anaerobic conditions can favor the growth of pests and diseases that can harm plants.
• Nutrient leaching: Organic matter can hold onto nutrients, but too much organic matter can lead to nutrients being leached out of the soil and into groundwater.
• Soil erosion: Organic matter helps to bind soil particles together, but too much organic matter can make the soil more susceptible to erosion.

How does soil organic matter affect soil water retention?

Soil organic matter acts like a sponge, absorbing and holding onto water. This is because organic matter has a large surface area and is made up of hydrophilic molecules, which means that they attract water.

The amount of water that soil organic matter can hold depends on a number of factors, including the type of organic matter, the texture of the soil, and the pH of the soil. In general, however, organic matter can hold up to 20 times its weight in water.

The increased water retention capacity of soils with high organic matter content has a number of benefits, including:

• Reduced need for irrigation: Soils with high organic matter content can hold more water, which means that they require less irrigation.
• Improved drought tolerance: Soils with high organic matter content are more drought tolerant because they can hold onto water for longer periods of time.
• ** Reduced risk of flooding:** Soils with high organic matter content can absorb more water during heavy rainfall, which can help to reduce the risk of flooding.

Connection between soil organic matter and soil water

Soil organic matter and soil water are closely connected. Soil organic matter helps to improve soil water retention, which makes more water available to plants. In turn, plants release water vapor into the atmosphere through transpiration, which helps to create clouds and precipitation.

Soil organic matter also helps to improve soil drainage, which prevents waterlogging and allows excess water to infiltrate deeper into the soil profile. This helps to recharge groundwater supplies and reduce the risk of runoff and erosion.

Overall, soil organic matter plays a vital role in the water cycle and is essential for healthy soils and ecosystems.

Here are some tips for maintaining optimal levels of soil organic matter:

• Add organic matter to the soil in the form of compost, manure, or mulch.
• Avoid over-tilling the soil, as this can break down organic matter.
• Plant cover crops to help protect the soil from erosion and add organic matter to the soil.
• Rotate crops to help prevent nutrient depletion and pest and disease problems.

Dr Murtadha Shukur thank you for your contribution to the discussion

The addition of organic matter to the soil usually increases the water holding capacity of the soil. This is because the addition of organic matter increases the number of micropores and macropores in the soil either by “gluing” soil particles together or by creating favorable living conditions for soil organisms. Too much compost or other organic matter, however, can increase the phosphorus concentration in soils to the point where the element may become a pollutant. So have your soil tested regularly to make sure it holds 20 to 40 pounds per acre of available phosphorus. Soil with more organic matter can absorb and keep in more water. This can improve crop productivity and reduce: tillage and irrigation costs and flooding, as water moves more slowly through the landscape after heavy rain. The addition of organic matter to the soil usually increases the water holding capacity of the soil. This is because the addition of organic matter increases the number of micropores and macropores in the soil either by “gluing” soil particles together or by creating favorable living conditions for soil organisms. Water-holding capacity is controlled primarily by soil texture and organic matter. Soils with smaller particles (silt and clay) have a larger surface area than those with larger sand particles, and a large surface area allows a soil to hold more water. Soil organic matter levels commonly increase as mean annual precipitation increases. Conditions of elevated levels of soil moisture result in greater biomass production, which provides more residues, and thus more potential food for soil biota. Soil biological activity requires air and moisture. Soil organisms form a complex food web, and soil organic matter is the base of the web. Most soil microorganisms use organic compounds in soil organic matter as carbon and energy sources. Some soil organisms feed directly on living roots, but most depend on dead plant matter. Water moves by gravity into the open pore spaces in the soil, and the size of the soil particles and their spacing determines how much water can flow in. Wide pore spacing at the soil surface increases the rate of water infiltration, so coarse soils have a higher infiltration rate than fine soils. With better soil structure, water infiltration through the soil increases and improves the soil's ability to absorb and hold water as well as reduces the potential for surface crusting of the soil. Soils with higher organic matter can infiltrate and store water at greater capacities.