Protein hydrolysates and amino acids
Hydrolysed proteins and free amino acids appear in six crop products. What they contribute beyond nitrogen — and why the source material matters.
What is protein hydrolysates and amino acids?
Protein hydrolysates are proteins broken into peptides and free amino acids by chemical or enzymatic hydrolysis. Source can be animal — collagen, leather, feather, blood — or plant, typically legume or cereal protein. Enzymatic hydrolysis of plant protein generally yields a better-defined product with a higher proportion of intact L-amino acids; harsh chemical hydrolysis can racemise amino acids into D-forms that plants cannot use, and can leave undesirable residues.
Source and process therefore matter considerably, and are frequently undisclosed.
What they do
Three contributions, in descending order of evidential strength. As a nitrogen source they supply organic nitrogen that can be taken up directly as amino acids or peptides, bypassing part of the energy cost of nitrate assimilation — useful under stress when that machinery is impaired.
As signalling and stress-protective agents, specific amino acids do specific jobs: proline and glycine betaine as osmolytes, glutamate in nitrogen metabolism signalling, tryptophan as the auxin precursor.
As chelators, amino acids complex micronutrient cations and improve their uptake and mobility, which is why amino-acid-chelated micronutrients are a product category in their own right.
Where does protein hydrolysates and amino acids appear in the range?
Protein hydrolysate appears in Calcium Boost, Cellular Boost, Grow Boost, Pollen Boost, Vita Boost and Vega Pro. Free amino acids are listed in Grow Boost (with amino acids at 18%) and Kelp Boost. L-tryptophan appears in Kelp Boost and Root Boost and has its own page. Glutamine appears in Pollen Boost, and glycine betaine in Cellular Boost.
Note a data issue to resolve: the Vita Boost page currently carries two incompatible formulations, one listing gluconic acid with Ascophyllum and protein hydrolysate at NPK 1-0-5, the other citing 18% amino acids with citric acid and magnesium sulfate at 0-0-2.
What does protein hydrolysates and amino acids not do?
They are not a substitute for mineral nitrogen at field rates — the quantities applied are small. Uptake of intact peptides through leaf surfaces is limited, so foliar amino acid products deliver less than the label percentage suggests. And amino acid content alone says little: the profile and the L-form proportion determine whether it is useful.