It’s true that plants grow from the top-down. In other words, it uses water and carbon dioxide from the air to grow. But you can’t remove key nutrients like:
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
Because if you deplete the soil from these nutrients, this deprives the plants of growing. For example, this is common in crop production and tree harvesting areas.
Nutrients from soil organic matter
Plants absorb nutrients directly from soil organic matter. For example, nitrogen (N), phosphorus (P), and potassium (K) are vital for plant survival. Together, these three soil nutrients make up NPK.
To a lesser extent, plants need calcium (Ca), sulfur (S), and magnesium (Mg) from the soil. But how do these nutrients contribute to plant growth?
|Element||Major Uptake Source||Purpose|
|Nitrogen (N)||Soil organic matter from soluble NO3 and NH4; Atmospheric N2 from nitrogen fixing species||Chlorophyll and plant leaf development and every day functions from DNA, RNA and proteins.|
|Phosphorus (P)||Soil organic matter; Soluble phosphorus.||Root growth and helping withstand environmental stress.|
|Potassium (K), Calcium (Ca) and Magnesium (Mg)||Soil organic matter: Soluble K+, Soluble Ca3+, Soluble Mg2+||Plant strengthening, growth and disease resistance.|