Which one is better for fertilizer sodium humate or humic acid powder？

Both sodium humate and humic acid are derived from humic substances and offer various benefits as soil amendments. The decision on which is better depends on the specific needs of your soil, plants, and application objectives. Here's a brief comparison:

Humic Acid:

Benefits:

Enhances soil structure, promoting good tilth and improved aeration.
Increases water retention capability.
Promotes nutrient uptake by plants.
Can stimulate plant growth and improve root development.
Drawbacks:
Needs specific conditions (acidic) for solubility which might require pH adjustments.
Raw humic acid can be more difficult to handle in some applications.

Sodium Humate:

Benefits:

Highly soluble in water regardless of pH, making it easy to apply.
Can also enhance soil structure and nutrient uptake.
Often acts as a chelating agent, improving the availability of micronutrients.
Drawbacks:
Sodium can be problematic in soils, especially in large amounts. High sodium can lead to soil dispersion, resulting in poor soil structure. In areas with existing high sodium or salinity issues, adding more sodium can exacerbate the problem.

Which is better?

The answer depends on your specific requirements:

If you're looking for a highly soluble product that can be easily applied in various conditions, sodium humate might be the choice.
If you're working with soils that already have sodium issues or are in regions where salinity is a concern, it might be better to consider using humic acid and adjusting conditions for its solubility.

Always keep in mind the specific needs of the crops or plants you're growing and the characteristics of the soil. It's a good practice to get a soil test before making amendments and, if possible, consult with a soil scientist or agronomist for personalized recommendations.