In the rugged Andean highlands of Peru, potato farmers face a delicate balancing act: maintaining yields while reducing reliance on synthetic fertilizers. A recent study published in *Applied Microbiology* offers a promising solution, demonstrating that microbial bioinputs can significantly cut fertilizer use without sacrificing productivity. The research, led by Miguel Tueros of the Estación Experimental Agraria Canaán in Ayacucho, Peru, explored the potential of *Bacillus subtilis* and *Trichoderma viride* to enhance potato growth under varying levels of NPK fertilization.
The study, conducted over two growing seasons, tested the effects of these microbial inoculants on two potato cultivars, INIA 303-Canchán and Yungay. The results were striking. By applying either *B. subtilis* or *T. viride* just once before planting, researchers found that they could reduce mineral fertilizer use by half while maintaining key growth metrics such as plant height, root dry weight, and stem number. In some cases, the microbial treatments even outperformed the full fertilizer regimen.
“Combining microbial inoculation with 50% NPK sustained growth responses comparable to 100% NPK,” Tueros explained. For instance, in the Yungay cultivar, *T. viride* at 50% NPK produced plant heights and root biomass comparable to those achieved with full fertilization. Meanwhile, *B. subtilis* boosted canopy vigor and stem number, particularly at full NPK levels.
The economic implications of these findings are substantial. Potato is a staple crop in the Andean region, and reducing fertilizer costs could provide significant savings for farmers. Moreover, the study highlights the potential for microbial bioinputs to play a larger role in sustainable agriculture, offering a climate-smart solution that aligns with global efforts to reduce synthetic input dependence.
“Plant height was the strongest correlate of yield,” Tueros noted, underscoring the importance of this metric as a proxy for productivity. The Yungay cultivar, in particular, showed higher overall yields, with the highest production achieved using *B. subtilis* at full NPK levels. However, even at reduced fertilizer rates, the microbial treatments maintained impressive yields, suggesting a flexible and adaptable approach to fertilization.
The research, published in *Applied Microbiology* and led by Miguel Tueros of the Estación Experimental Agraria Canaán, provides a compelling case for integrating microbial bioinputs into potato production systems. As the agriculture sector continues to seek sustainable solutions, these findings could pave the way for broader adoption of bioinputs, ultimately shaping the future of climate-smart farming.