Organic biostimulants: an approach to their characterization and management within an integrated, sustainable and competitive agricultural strategy

The following article shows the results of an exhaustive comparative study of both analytical characterization and agronomic efficacy of 4 biostimulant products from different sources of raw material (animal and plant origin) and methods of production (chemical or enzymatic hydrolysis). Regarding the analytical characterization, the results show a greater degree of hydrolysis and a more complete and balanced amino acid profile of the Terra-Sorb® biostimulant compared to other products of plant origin and chemical hydrolysis. The high degree of racemization of biostimulants of plant origin is also indicative that at some point in the process there has been a chemical treatment (acid hydrolysis) while the Terra-Sorb® product (enzymatic hydrolysis) is the only one that maintains a high proportion of L-α-amino acids. On the other hand, in the comparison of the agronomic efficacy carried out under a test model in pepper and saline stress, it becomes clear how the variable quality depending on the origin and method of obtaining determines the agronomic efficacy of the amino-based biostimulants. The test reveals how the highest productive yield of the Terra-Sorb® biostimulant in saline conditions is due to the free amino acid content of the product and not to a simple nitrogen supply. In addition, equating application doses according to the percentage of free amino acids, it is revealed that other bioactive compounds of the Terra-Sorb® product would enhance this greater tolerance to stress observed in the treated plants.