Overview

Agricultural biologicals are a rapidly growing class of agronomic inputs derived from microbes, plants, or other living organisms. The global market value of biologicals is predicted to exceed 33 billion USD by 2030 (Fortune Business Insights 2023). These biological technologies harness nature-based solutions for crop production and protection and are classified into two major categories: biostimulants and biopesticides.Biostimulants are defined by the USDA in the 2018 Farm Bill and the Plant Biostimulants Act of 2023 as "a substance or micro-organism that, when applied to seeds, plants, or the rhizosphere, stimulates natural processes to enhance or benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, or crop quality and yield." In the United States, biostimulants are not federally regulated but are typically registered at the state-level (similar to fertilizers). Biostimulants can be further classified by their source material as microbial or natural products.

• Microbial biostimulants are living microbes (e.g., bacteria and fungi) that can carry out a range of plant growth promoting activities such as improved plant water and nutrient use efficiency, enhanced germination and plant development, and increased stress tolerance. The term "biofertilizer" is sometimes used interchangeably with microbial biostimulant and refers to microbial products that improve plant nutrient acquisition.
• Natural product biostimulants are natural substances produced or extracted from microbes, plants, or other organisms. Natural products encompass diverse materials ranging from seaweed extracts, organic acids (i.e, humic and fulvic acids), vitamins, and biopolymers (i.e., chitin or chitosan).

Biopesticides are substances derived from living organisms intended for preventing, destroying, repelling, or mitigating any pest. Biopesticides include naturally occurring substances that control pests (biochemical pesticides), microorganisms that control pests (microbial pesticides), and pesticidal substances produced by plants from added genetic material (plant-incorporated protectants or PIPs). Biopesticides are federally regulated by the EPA (find a list of registered biopesticide active ingredients here).

Fertilizers are any materials that supply plant-bioavailable macronutrients and/or micronutrients. Fertilizers can be organic or inorganic (derived from living organisms or non-living substances) and natural or synthetic. An important distinction between fertilizers and biostimulants is plants directly uptake nutrients from fertilizers, while biostimulants stimulate beneficial biological processes – which can include increased nutrient acquisition.

Summary

Agricultural biologicals are a promising class of inputs engineered for reducing dependence on synthetic chemicals and for supporting crop health and productivity. Biologicals can be biostimulants that stimulate a range of beneficial processes, or biopesticides that controls pests. Biologicals can be living microbes, or natural products derived from living organisms. Biopesticides are federally regulated, but biostimulants are not.