Developing Biostimulants From Agro-Food and Industrial By-Products

Abstract

In modern agriculture, seeking eco-friendly ways to promote plant growth and enhance crop productivity is of priority. Biostimulants are a group of substances from natural origin that contribute to boosting plant yield and nutrient uptake, while reducing the dependency on chemical fertilizers. Developing biostimulants from by-products paves the path to waste recycling and reduction, generating benefits for growers, food industry, registration and distribution companies, as well as consumers. The criteria to select designated by-products for valorizing as biostimulant are: absence of pesticide residue, low cost of collection and storage, sufficient supply and synergy with other valorization paths. Over the years, projects on national and international levels such as NOSHAN, SUNNIVA, and Bio2Bio have been initiated (i) to explore valorization of by-products for food and agriculture industries; (ii) to investigate mode of action of biostimulants from organic waste streams. Several classes of waste-derived biostimulants or raw organic material with biostimulant components were shown to be effective in agriculture and horticulture, including vermicompost, composted urban waste, sewage sludge, protein hydrolysate, and chitin/chitosan derivatives. As the global market for biostimulants continues to rise, it is expected that more research and development will expand the list of biostimulants from by-products. Global nutrient imbalance also requires biostimulant to be developed for targeted market. Here, we review examples of biostimulants derived from agricultural by-products and discuss why agricultural biomass is a particularly valuable source for the development of new agrochemical products.

Keywords: agrochemical; bio-economy; biofertilizer; organic waste stream; plant extract; sustainable farming.

FIGURE 1

Possible scenario in valorization chain of biostimulants from waste streams. Food industries and growers generate substantial amount of waste material and they are seeking methods to valorize as it costs to process the by-products. Food industries have the capacity to transport the by-product out of sites. Growers, however, usually lack the logistic means to process the by-products. Thus, a limiting factor for growers to valorize the crop residues is the cost of transport. As the first step toward valorization, Company a has the expertise in extraction and formulation from by-products. Company C–E, and G are heavily involved in the production and marketing of biostimulant products and they invest in registration and distribution. In spite of the ability to produce bioactive ingredients, these companies might still need assistance from Company a in extraction and formulation. Company C–E are also selling biostimulants to intermediate companies (Company F), who produce seeds, substrates or fertilizers. It is likely that one new biostimulant will be marketed as substrate, soil improvers or seed-coating. The ultimate target groups of biostimulants are crop growers. The proved efficacy of one biostimulant from growers will inspire the identification of chemical structure by Company B, carrying out synthesis of analogs. Consequently, it provides further knowledge into the valorization chain since the extraction and formulation can be designed to isolate the targeted bioactive ingredients.