Humic acid is a natural polymer organic matter that can enhance soil and fertilizer nutrients. But have you ever thought about what factors will affect this effect? We will explain it to you systematically in the following content.
In short, the synergistic effect of humic acid on soil and fertilizer nutrients is affected by the type, functional group, addition amount, and environmental pH of humic acid.
1. Types of humic acid
Different types and sources of humic acid have different synergistic effects on soil and fertilizer nutrients. For example, research has confirmed that there are obvious differences in the effects of humic acid from different origins on the soil nitrogen, phosphorus and potassium content of pakchoi at each growth stage.
2. Functional groups in humic acid
Certain specific functional groups in humic acid can undergo binding reactions with urea, ammonium ions, phosphates and potassium ions. Therefore, the number of humic acid binding sites affects the synergistic effect of humic acid on soil and fertilizer nutrients.
3. The amount of humic acid added
Different amounts of humic acid added will affect the synergistic effect on soil nutrients. On the one hand, different amounts of humic acid added affect the release rate of nutrients in the soil. Research shows that the release of N, P, and K in the soil is linearly related to the amount of humic acid added. On the other hand, the added amount of humic acid has different effects on the transformation of nutrients after fertilizer application. Only when the added amount of humic acid reaches a certain level will it have an activating effect on soil fixed phosphorus. In addition, studies have shown that the greater the amount of humic acid added, the stronger its inhibitory effect on the volatilization of urea and ammonia.
4. PH value of application environment
In addition, the pH value of the application environment affects the competitive adsorption effect of humic acid and phosphate. Under low pH conditions, humic acid and phosphate have a stronger competitive effect on the adsorption sites on goethite, gibbsite and soil.
In summary, the synergistic effect of humic acid on soil and fertilizer nutrients is affected by four factors: the type of humic acid, the number and addition amount of functional groups, and the environmental pH value.