Studies have found that over the last 70 years, the level of nutrients in many foods has fallen between 10 and 100 percent. Based on that, there are some estimates that an individual today would need to consume twice as much meat, three times as much fruit, and four to five times as many vegetables to obtain the same amount of minerals and trace elements available in those same foods in 1940. There are many who believe this overall decline in nutrient density is likely having an impact on human health and well-being.
Restoring the nutrient density of food is not as simple as just adding these minerals and trace elements to the soil. Rarely are minerals and trace elements completely absent from the soil. Rather, most deficiencies are due to soil conditions not being conducive for nutrient uptake. The minerals are present in the soil but are not plant-available.
It is estimated that around 85 to 90 percent of plant nutrient acquisition is microbially-mediated. These microbes are plant-dependent, surviving on carbon compounds exuded by the plant roots in exchange for making soil nutrients available to the plants. As such, soil health practices which increase the microbial biomass and activity in the soil should result in better nutrient acquisition by the plant and ultimately, higher nutrient density in food derived from the plants.
There is recent research which is beginning to show that soil health is connected to human health and that ties soil health practices to improved human health and nutrition.
For example, new research by an interdisciplinary team at Penn State, recently demonstrated that soil disturbance can directly impact a key dietary factor associated with long-term human health. This study found that soil tillage may significantly reduce the availability of ergothioneine (ERGO) in crops. ERGO is an amino acid produced by certain types of soil-borne fungi and bacteria that is known as a “longevity vitamin” due to its potent antioxidant properties.
Research suggests that a lack of ergothioneine in the diet may result in increased incidences of chronic diseases of aging, such as Parkinson’s Disease and Alzheimer’s, and reduced life expectancy.
The researchers found that ERGO concentrations declined as tillage intensity increased, due to tillage disrupting the fungi populations in the soil and compromising the availability of this important amino acid.
The study was comprised of a randomized complete block design with three tillage treatments — moldboard plowing/disking/harrowing (MB), which represents the most intense tillage; chisel plowing/disking/harrowing (CD), which represents a medium amount of tillage; and no-till (NT) — each replicated four times. The crops grown in the study include maize, soybeans and oats.
Results of the study found that as tillage increased from NT to MB, ERGO content declined by 32% for maize, 33% for soybeans and 28% for oats. In addition to being associated with reduced ERGO concentrations, increased tillage also was associated with reduced crop yields.
The full news release on the study can be read at Soil tillage reduces availability of ‘longevity vitamin’ ergothioneine in crops | Penn State University (psu.edu) .
Preliminary results from another study recently conducted by the University of Washington have found that farms that used regenerative agriculture practices such as no-till farming, cover crops and diverse crop rotations produced crops with higher levels of certain vitamins, minerals and phytochemicals than farms using conventional practices.
The researchers tested the influence of soil health and soil health scores on the nutrient density of crops by measuring eight pairs of farms using regenerative agriculture practices or conventional practices in the states of North Carolina, Pennsylvania, Ohio, Iowa, Tennessee, Kansas, North Dakota and Montana. Each regenerative agriculture farm was paired with a nearby conventional farm that grew the same crop variety, such as peas, sorghum, corn or soybeans.
When compared to crops from conventional farms, crops from regenerative agriculture farms had 34% more vitamin K, 15% more vitamin E, 14% more vitamin B1 and 17% more vitamin B2. The regenerative agriculture crops also had 11% more calcium, 16% more phosphorus and 27% more copper.
The study also compared wheat crops. Regenerative wheat crops were planted in a crop rotation pattern that included cover crops between crops of spring barley and winter wheat. The regenerative wheat samples had 41% more boron, 29% more magnesium, 48% more calcium and 56% more zinc than conventional wheat samples.
The results from this study are considered preliminary due to the relatively small sample size but more studies are planned to better quantify how differences in soil health affect the quality of crops that come from that land.
The full results of this study published in the science journal PeerJ can be found at Soil health and nutrient density: preliminary comparison of regenerative and conventional farming [PeerJ] .
These research results suggest that applying soil health principles can be important, not only for the environment, but also for human health, as it appears that healthy soils produce healthier foods.