Greener Yields: How Biofertilizers Combat Nitrogen Runoff and Boost Sustainability

By: Francisco Montaner

This photo showcases eutrophication in Taihu Lake (Xia et al. 2020)

Nitrogen runoff in agroecosystems is a major contributor to non-point source pollution, which occurs when nitrogen, primarily from fertilizers and agricultural activities, is carried by rain or irrigation into nearby rivers, lakes, and oceans. This runoff has a huge environmental impact introducing excessive amounts of nitrogen into aquatic ecosystem particularly the contribution to eutrophication, where high nutrient levels in water bodies lead to excessive growth of algae. The overuse of fertilizers greatly intensifies nitrogen runoff, as surplus nitrogen is easily washed away into surrounding water systems. Biofertilizers offer a cost-effective and eco-friendly alternative to conventional chemical fertilizers. In a study conducted by Sun and colleagues, the effects of biofertilizer mixtures combined with conventional chemical fertilizers were evaluated to assess nitrogen runoff loss and crop yield. Sun and colleagues tested various treatments, including no fertilization, conventional fertilization, a combination of biofertilizers and conventional fertilization, and biofertilizers alone. They found that nitrogen runoff from conventional fertilizers was 3.6 times greater than that from plots without fertilization. In contrast, the use of biofertilizers reduced nitrogen runoff loss by 51% to 61% compared to conventional fertilizers. Furthermore, all fertilizer treatments significantly increased crop yields, with the combination of biofertilizers and conventional fertilizers resulting in yields that were 5% and 4% higher than those achieved with conventional fertilizers alone. These findings provide an alternative to conventional fertilizers that is less harmful to the environment. While relying solely on biofertilizers may result in lower crop yields, it promotes a healthier environment overall.

Text: 

Sun B, Gu L, Bao L, Zhang S, Wei Y, Bai Z, Zhuang G, Zhuang X. 2020. Application of biofertilizer containing Bacillus subtilis reduced the nitrogen loss in agricultural soil. Soil Biol. Biochem. 148:107911. doi: https://doi.org/10.1016/j.soilbio.2020.107911.

Photo:

Xia Y, Zhang M, Tsang DCW, Geng N, Lu D, Zhu L, Igalavithana AD, Dissanayake PD, Rinklebe J, Yang X, et al. 2020. Recent advances in control technologies for non-point source pollution with nitrogen and phosphorous from agricultural runoff: current practices and future prospects. Appl. Biol. Chem.63(1). doi: https://doi.org/10.1186/s13765-020-0493-6.