Soil & Plants (Part 87)

By: John Ferguson

Remember the old saying by Hippocrates, “Let food be thy medicine”? A new study from the University of East Anglia in cooperation with Harvard University reinforces this. They found that eating a cup a day of blueberries improved heart health and reduced the risk of cardiovascular disease by 15%. American Journal of Clinical Nutrition (2019) . Many varieties of blueberries grow well in the Houston area and there are several pick your own blueberry farms in the region. A mature rabbit-eye blueberry plant can produce as much as 15 pounds of berries. Many pollinators love the flowers and many species of birds relish the ripe berries. When blueberries are grown next to woodlands the plants get better pollination and produce more fruits (USDA). The USDA also found that growing native grasses next to blueberry plants corrected signs of iron (Fe) deficiency. 

The journal Environmental International (2019) had a recent article that demonstrated that restoring environments to a wide range of plant species promoted good bacteria over bad bacteria. They found a direct connection between a healthy ecosystem and human health. In particular they found it increased bacteria that boost our immune systems. This is a good reason to increase the diversity of plants in our landscape. The greater the diversity of grasses, flowers, herbs, shrubs and trees the more health benefits one’s garden provides from microbes and earthworms, to butterflies and birds. 

A problem that gardeners often face in Houston is the disease Phytophthora. Research at Cornell University has found that it can be controlled using certain plants like Brassicaceae family as cover crops. These include mustards, cabbages, broccoli, etc. as they have sulfur compounds in them called “gluconsinolates” which give some members of this family their spicy taste. When these plants are turned under, they act as a natural fungicide for this disease. They also have deep fast-growing taproots that helps break up hardpan and loosen the soil. Additionally, they return a lot of nitrogen to the soil and return 3.5 time more carbon than other species. A bonus is that many pollinators love to feed on the pollen and nectar of the flowers. 

Researchers at the University of Sheffield’s physics lab have found that photosynthetic bacteria that directly use sunlight for energy, use a mechanism of nature called quantum entanglement to communicate with each other. Similar work at the University of Oxford stated it would explain the remarkable speed of enzyme-catalyzed reactions we find in nature.    

The June issue of Science News had a summary of a research paper published in the journal Functional Ecology. They discovered that some species of plants can grow directly from rock (no soil required). Species of plants that have this ability to secrete malic and citric acid from their root tips that dissolve nutrients (elements) directly from the minerals composing the rock. 

A study published in the journal Environmental Sciences Europe (2019) has found another problem caused by use of the herbicide glyphosate (think Round-Up). One of the breakdown products of glyphosate is a toxic chemical called AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) where it is slow to degrade further. In the soil it harms earthworms preventing them from growing properly and performing their normal ecosystem services from aerating soil to eating weed seeds. It also causes reproductive damage in earthworms. Bacteria and fungi are also sensitive to this chemical preventing them from cycling nutrients and storing carbon in the soil. This chemical has also been found to cause changes in the reproductive cycle, metabolism, growth and behavior of fish, insects and mollusks. We now have companies marketing meatless burgers made from genetically engineered soy that requires very high levels of the cancer-causing chemical glyphosate. 

Reasons to avoid artificial fertilizers continue to grow. A new study from Cornell University has found that the polluting emissions from artificial fertilizer plants (think ammonia an extremely toxic and potent greenhouse gas) were 100 time higher than the fertilizer industries self-reporting estimates. When one uses these toxic products, they contribute to climate change during manufacture, escape of methane from the fertilizer, pollution of our waterways and destruction of organic matter in the soil releasing carbon dioxide. Journal Elementa Science of The Anthropocene (May 2019).    

Over the last few years I have been doing a lot of study on how plants use nutrition (minerals and elements) to grow. I recently read a paper published in the American-Eurasian Journal of Agronomy (2010) on the effects of chicken manure on the growth of sweet potatoes. Poultry manure has been used for generations as a fertilizer for plants and works well if only used occasionally. Long term usage can lead to a salt buildup in the soil which is harmful and it is not a balanced fertilizer, hence repeated usage can lead to chemical imbalances in the soil. This study found that small amounts of poultry (chicken) in this case gave satisfactory to good results. However as increasing amounts of manure were applied yields actually declined. 

Note 1: Never use poultry manure from factory farms as it is often contaminated with antibiotics, arsenic, and other toxic materials. 

Note 2: Poultry manure is high in water soluble phosphorous (P). When there are high levels of phosphorous in the soil, the extremely beneficial mycorrhizal fungi DO NOT colonize a plants roots. The picture below courtesy of Mike Amaranthus, PhD, illustrates the importance of mycorrhizal fungi. This study was done in Southern California in highly saline soils in a very dry drought prone area. The only difference between different sides of the fields is the lemon trees on the right had been inoculated with mycorrhizal fungi at planting time.    

Note 3: Over 80% of plants on earth require mycorrhizal fungi to be healthy. 

A study of 3,600 people by the Barcelona Institute for Global Health found that adults who were exposed to natural outdoor environments as children, have several health benefits. These range from better cognitive development, better mental and physical health when as children they were exposed to green space (gardens, parks, forests, urban parks) and blue    

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space (canals, ponds, creeks, rivers, lakes, beaches, etc.). International Journal of Environmental Research and Public Health (2019) 

The Australian National University has found that children who spend one half an hour per day out in the sun decrease their risk of inflammatory bowel disease (IBD). Journal of Pediatric Gastroenterology and Nutrition, (2019). This is another reason school gardens and playing outside are important to their health. 

Our pollinators are in serious decline and a recent study (2018) by the University of Hawaii confirmed that exposure to glyphosate (Round-Up) disrupts the healthy gut flora of bees. Other studies have found similar gut disruption effects in chickens and cows. Several studies have found that glyphosate targets an enzyme found in beneficial gut bacteria that plays an important role in detoxifying harmful chemicals, and it is now considered a possible cause of the rise in modern human diseases worldwide. 

To make matters worse testing by the consumer advocacy group, Moms Across America (MAA), has revealed that the meat free Impossible Burger (made from genetically engineered soybeans) is full of glyphosate. This chemical also is believed to be related to the tremendous increase of nonalcoholic fatty liver disease (NAFLD). 

The reasons to “go organic” in our gardening and “eat organic” in our food continue to increase.