Humic acid and root-zone development
How humic and fulvic substances work in the soil and at the root, what makes a good product, and how to use it for a stronger root zone.
Read the previous partProtein hydrolysates are mixtures of amino acids and short peptides made by breaking down plant or animal protein. Studies report that they can support nutrient uptake, nitrogen use and recovery from stress. They do not replace fertilizer; the aim is to help the crop use the nutrients you already apply, so the benefit depends on the source, the dose and the crop.
Part 5 of 6 in the Plant Science Series by Gafar Laiya: plant physiology and biostimulant science, in plain language. Published 30 October 2026.
What nutrient-use efficiency means
Nutrient-use efficiency is how much of the fertilizer you apply ends up in the crop. A lot is usually lost: nitrogen leaches or escapes as gas, phosphorus is locked up in the soil, and potassium and micronutrients can be unavailable. A crop with a weak root system or under stress takes up even less. Improving efficiency means a better root system, a healthier plant and better timing, and biostimulants such as protein hydrolysates are one of the tools.
What a protein hydrolysate is
| Feature | What it means |
|---|---|
| Raw material | Plant protein (for example from legumes or crop residues) or animal protein (for example hides, feathers or fish). The source changes the amino acid profile and what the label can say |
| Process | Protein is broken down by acid, alkali or enzymes. Enzymatic processes tend to keep more of the natural amino acids and peptides, while harsh processes can damage some |
| Content | A mix of free amino acids and short peptides. Both may act as nutrients and as signals |
| Form | Usually liquid or powder for foliar and root-zone use |
What studies report
- Better uptake and use of nitrogen and other nutrients, partly through effects on enzymes that handle nitrogen in the plant.
- A larger, more active root system in some crops.
- Faster recovery from stresses such as transplanting shock, heat, cold, salt and drought.
- Better quality in some vegetable and fruit crops.
The effects vary. Studies differ by crop, dose, timing and product, and some trials show no benefit. The aim is to improve results with what you already apply, not to promise a yield.
When growers use them
| Situation | How it is used |
|---|---|
| Transplanting and early growth | Root-zone or foliar application to support re-establishment |
| Before or after heat, cold or dry spells | Foliar application to support recovery |
| Vegetative growth | With a balanced fertilizer programme, to support uptake |
| Flowering and fruit growth | As the crop's demand rises, in line with the label |
Do not use amino acid sprays as a way to cut fertilizer sharply. Reduce fertilizer only if a soil or leaf test and a trial on your own farm support it.
What to ask a supplier
- What is the source of the protein: plant or animal?
- How is it made: enzymatic, acid or alkali?
- What is the content of free amino acids and total amino acids?
- Is it listed in Schedule VI of the Fertiliser Control Order? Only listed biostimulants can be sold in India.
- What are the dose, timing and mixing instructions, and is it safe on my crop?
What protein hydrolysates do not do
- They do not replace nitrogen, phosphorus or potash fertilizer.
- They do not correct a soil problem such as salt, compaction or poor drainage.
- They do not guarantee a result. Test on a small area first.
Last in this series: biostimulants for salinity and drought stress.
Written by Gafar Laiya, founder of Gujarat Bio Organics, working with farmers since 2006. Results differ from farm to farm with soil, weather, crop and management. Farmer experiences on this site are their own reports, not a promise of results.
Questions
Are amino acid fertilizers the same as protein hydrolysates?
Products sold as amino acid fertilizers are often protein hydrolysates, but the name does not tell you the source, the process or the content. Check the label.
Can I reduce fertilizer if I use amino acids?
Do not cut fertilizer on the strength of a label. Confirm with a soil or leaf test and a trial on part of your field.
Is a plant-based hydrolysate better than animal-based?
Neither is better for every crop. The source changes the profile and what you can claim, for example for organic certification. Check what your buyer or certifier requires.
Do amino acid sprays burn leaves?
A product used at the right dose is usually safe, but a high dose or a hot-day spray can harm leaves. Follow the label.
Further reading
- Colla G, Nardi S, Cardarelli M, et al. (2015). Protein hydrolysates as biostimulants in horticulture. Scientia Horticulturae 196:28-38.
- Calvo P, Nelson L, Kloepper JW (2014). Agricultural uses of plant biostimulants. Plant and Soil 383:3-41.
- du Jardin P (2015). Plant biostimulants: definition, concept, main categories and regulation. Scientia Horticulturae 196:3-14.
These are starting points for readers who want to look at the research. Findings differ between crops, products and conditions.
Continue the series
Biostimulants for salinity and drought stress
How salt and drought hurt crops, which fixes come first, and where seaweed, amino acid and humic biostimulants may help the plant cope.
Read the next partSee all six parts of the Plant Science Series.
For business buyers and formulators
Technical notes on our business site (b2b.gujaratbio.com), for manufacturers, importers and brand owners:
Biostimulant manufacturer in India: bulk, private label and export
Send us your enquiry
Tell us your crop, the problem and your location, and send a photo if you can. Our team replies on WhatsApp or calls you with what to check, which product suits and where to buy it near you.