Organic nutrients in soil represent any type of nutrient or material that is originally produced by living organisms and is then returned to the soil via the decomposition process. It contains a range of materials, some of which include the intact and original tissues of formerly living animals and plants. Also common as an organic nutrient is humus, the substantially decomposed mixture of materials found in most organic soil. Mineral soil, the alternative to organic soil, is not a vital cropping soil and does not benefit from organic nutrients as much as organic soil does (although mineral soil can contain anywhere from a trace to 30% organic matter). Most organic nutrients originate from plant tissue, and consist of a variety of components. Some of these components vary in size and frequency. They include microorganisms (anywhere from 10-40% of organic nutrients are microorganism-based) and humus, which is otherwise serving the function of being a stable organic matter. Anywhere from 40-60% of organic nutrients will be derived from humus, because it is the predominant organic material present in the soil. Organic materials present within the soil often serve two main functions:

  1. Because soil organic matter and therefore nutrients are derived primarily from plant residues, it contains all of the essential plant nutrients. Accumulated organic matter is a storehouse of plant nutrients, and contains all of the essential nutrients necessary to feed your soil.
  • Humus, the stable organic matter that holds and absorbs nutrients in a plant-available form, is an organic material which is essential for delivering organic nutrients to plants through soil. Upon decomposition, organic matter turns into organic nutrients in a plant-available form.

In this manner, a nutrient cycling system is established and maintained via an equalization of the rate by which decomposition and nutrient cycling both take place. When the rate of organic matter and nutrient addition into the soil dips below the rate of decomposition, soil organic matter and nutrients decline. Oppositely, when the rate of organic matter and nutrient addition into the soil rises above the rate of decomposition, the amount of organic matter and nutrients present within the soil rises. Organic nutrients present within the soil improve soil structure drastically, along with microorganisms and fungi. Together, they work to bind soil particles into larger aggregates (aggregation is important for good soil structure, aeration, water infiltration and erosion along with crusting resistance). Soil aggregation has been positively linked to increased soil stability through scientific research already. Organic nutrients that can only be found in organic soil are essential for guaranteeing that soil aggregation will occur via the binding of soil particles into aggregates. The stable fraction of organic nutrients and materials within soil contributes mainly to nutrient holding capacity and soil color. Because organic nutrients within soil decay very slowly, they have less influence on soil fertility than other materials do.

Soils high in organic matter, materials, and nutrients will allow plants to grow bigger and stronger than they otherwise would have if being grown in averagely kept soil. Building up and maintaining high soil organic matter levels is beneficial to your plants because it helps them to develop a more extensive and versatile root system, which in addition to allowing your plant to gain nutrients from a larger volume of soil also gives it a higher chance of surviving and thriving. Scientifically speaking, the best overall strategy for soil nutrient management is to enhance the levels and amounts of organic matter within soils. Soil organic matter, together with residues, provide natural chelates that plants can utilize. These chelates help your plants absorb micronutrients such as zinc, copper, and manganese. The improved soil tilth and other growth-promoting substances produced when organic matter decomposes will also ensure that your plants gain a footing in their development early on.

Organic nutrients in your soil are important to have for the sake of your plants. They can benefit in a variety of ways just from you strengthening your soil quality. Implementing organic nutrients into your soil is as simple as testing your soils regularly to determine their nutrient statuses. If manures, fertilizers, or lime are needed in order to introduce organic matter to the soil content, they should be introduced and left to mix. You can also enhance your soil structure and reduce field runoff by minimizing soil compaction damage. Cover crops should be utilized to tie up nutrients in the off season while enhancing soil structure, reducing runoff and erosion, and providing microbes with fresh organic matter.