Resumen
- Plant growth promoting microorganisms (PGPMs) are inhabitants of the rhizosphere that are able to provide better growth and biomass accumulation. Current agronomic practices have depleted these communities, which has created the opportunity for the development of commercial inoculants. These products use strains that are able to interact with a wide range of plant species and survive in diverse environments. The use of these generalist strains is required for providing a widespread solution that aggregates enough demand to reach market scale. Growth promotion by generalist strains may be suboptimal in comparison to the effect provoked by native and host-specific populations, but these specialist strains are not a market-available solution. In this work, we assess the nitrogen, phosphorus and potassium (NPK) use efficiency provided by commercial inoculants to cassava plants using Data Envelopment Analysis (DEA) to demonstrate the advantages of conceiving nutrient-limited yield as a production function. We also estimate the prospective production frontier that commercial inoculants can provide to cassava plants. Our results suggest that commercial inoculants have potential for improving cassava yields via improved NPK use efficiency. The methods presented here offer an ecological/economic production framework for the assessment of PGPMs and PGPMs-based commercial inoculants that can be extended to other laboratory, greenhouse or field situations. The simple, intuitive and graphical approximation that DEA offers will facilitate the understanding of the concept of technical efficiency and the role of commercial inoculants on closing yield gaps.