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Commercial Fertilizer is Harming our Soils
by LuAnn Rolling, District Conservationist
Regenerative farming practices emphasize nutrient uptake from soils through natural soil biological cycles. This approach uses microbes and carbon compounds to produce crops naturally rather than relying entirely on highly soluble “salty” fertilizer inputs for plant nutrition.
According to James Hoorman, writing for Ohio’s Country Journal in May, 2022, before commercial synthetic fertilizer, historically, soil microbes provided about 80% of soil nitrogen (N) through the efficient process of microbial N fixation. For the first time, the total fixed N supplied by microbes is less than the amount of applied synthetic N from fertilizer. Excess salt based or soluble fertilizer is disrupting the natural soil balance.
Dr. Christine Jones, in an article titled Nitrogen: the double-edged sword, says that globally, over $100 billion of nitrogen fertilizers are applied to crops and pastures every year. Between 10 and 40% of the applied N is taken up by plants. The other 60-90% is leached into water, volatilized into the air or immobilized in soil. She says that the application of high rates of inorganic nitrogen in agricultural systems has had many unintended negative consequences for soil function and environmental health.
Biological release of plant nutrients has far greater potential for plant mineral uptake than relying entirely on soluble nutrients from fertilizer. There are many natural biological ways to efficiently, profitably, and ecologically uptake plant nutrients without using soluble or salty fertilizers. We are just starting to fully understand these biological processes.
The soil is a living system that is sensitive to highly soluble salt inputs. In low input (sustainable, biological, regenerative) agriculture, highly soluble soil inputs are used sparingly.
Hoorman says that in countries where crops are fertilized with synthetic N fertilizer, nitrogen use efficiency is very low. In the USA, about 54% of all N fertilizer applied to corn crops is wasted. In biological based systems, nitrogen is used efficiently by both microbes and plants. Soil compaction and poor soil structure robs soil microbes of needed oxygen and nitrogen, destroying the opportunity to reduce N inputs. Heavy use of salt fertilizers means soils will either leach out or use large quantities of water to offset the high salt inputs. Using regenerative practices (cover crops, no-till, manure, compost, humates) enhances soil life and improves nutrient efficiency.
