Covid-19 and the “gut” of the plant

The Covid-19 pandemic has caused havoc all over the world. However, microbes such as viruses, bacteria, fungi and other primitive forms of life were here long before us, are much more abundant and have a profound influence on various aspects of our daily lives. Think of the “good microbes” as those used for fermentation of alcoholic beverages, making of dairy products, compost and even the production of antibiotics, antimycotics and various other industrial enzymes. In contrast, the “bad microbes” such as rot and disease-causing microorganisms can lead to food and water spoilage and may eventually destroy its host as in the case of the Covid-19 virus. If it weren’t for an effective immune system, mankind as a whole would have been wiped out long ago by pandemics such as the infamous Black Death of 1347 and the Spanish Flu of 1918.

The immune system co-evolved with trillions of gut-bacteria, archaea, fungi, protists and viruses collectively known as the gut-microbiome or gut-microflora. All work together in the gastrointestinal tract to keep us healthy and protect us against unwanted microbes. The microbiome, which can make up as much as 1-2kg of an average person’s body weight, also plays an important role in nutrient and mineral absorption, synthesis of enzymes, vitamins, amino acids, and the production of short-chain fatty acids. The gut contains 70-80% of the body’s immune cells and the “good” bacteria help keep your “bad” bacteria in check.

Although these processes in the body and in the soil function differently, there are obvious similarities. The soil surrounding the plant’s root zone is effectively its digestive system or “gut”. A healthy rootzone containing high numbers of beneficial microbes produces healthy plants, which bear nutrient-rich crops. A recent publication in the Virus Research Journal (13 May 2020) found that improving the gut microbiota profile by personalized nutrition and supplementation known to improve immunity can minimize the impact of Covid-19 in the elderly and immune-compromised patients. The more nutrient-rich food we consume, the healthier our microbiota will be and the healthier we will be.

Just as we have unwittingly depleted vital microbes in the human gut through overuse of antibiotics and eating highly processed foods, we have destroyed soil microbiota essential to plant health through overuse of certain chemical fertilizers, fungicides, herbicides, pesticides, failure to add sufficient organic matter (upon which they feed), and heavy tillage.  These excessive agricultural practices have reduced soil fertility and proven detrimental to the functioning of the natural root-microbiome.

The decrease in soil health over several decades has resulted in lower production levels, a decline in product quality as well as an increase in the use of agrochemicals and pesticides. Thus the growing interest in “regenerative agriculture”, “soil health”, “sustainable soil management”, “biological farming”, “organic farming”, “minimum or no-tilling”, etc. All these practises share a common goal, which is to increase soil health and stimulate soil life in the rootzone of the plant.

RESTORING SOIL HEALTH IN ORCHARDS AND VINEYARDS

By using biological- and regenerative agriculture methods, agrochemical inputs can be reduced and soil health can be restored. This is the basis of sustainable soil health programmes, and nutrient-rich crops produced in such a manner are in great demand by health-conscious consumers worldwide. A tried and trusted approach used successfully by our company to restore soil health specifically in orchards and vineyards is as follows:

1. Analyze and make physical and chemical corrections in the soil.

To improve soil health, it must be ascertained whether there are any physical problems or plant nutrient deficiencies in the soil. Physical soil preparation, e.g. layer removal, compaction and application of soil enhancers is a prerequisite. By analyzing soil and leaf analyses, it is possible to determine whether there is a mineral deficiency and to confirm if nutrients can be absorbed by the plant.

2. Use environmentally friendly fertilizers and chemical sprays.

Certain fertilizers and chemical sprays can adversely affect root growth and soil microbes. Thus be aware of the salting- and acidification effects of fertilizers, as well as the fact that chemical sprays kill beneficial microbes and predators. The use of toxic sprays should be kept to a minimum or stopped altogether.

3. Optimize water quality and irrigation scheduling.
   Measure water quality (dissolved salts/minerals, pH, harmful organisms) and optimize. The best irrigation system is meaningless without the proper scheduling system. Scheduling involves managing the amount of water given and at what frequency. This involves gathering data, processing and calculations, applying irrigation and then monitoring. By managing the soil water content and water table, one manages the gas exchange in the soil, which in turn directly affects optimal photosynthesis, root formation, soil life and the accessibility of plant nutrients.

4. Increase ground cover and biodiversity (orchard floor management).

To restore biological activity in soil, the use of mixed cover crops and natural soil cover is encouraged. If crop rotation and/or mixed cover crops are used, soil aggregation is promoted and fewer weeds, insects and plant diseases are present. Consequently, the need for pest and disease control is reduced, and stress on plants and the ecosystem is much lower. This leads to reduced input costs and higher profitability.

5. Nourish and stimulate soil life.

Beneficial soil microbes can make significant contributions if we provide them with a suitable habitat (soil with sufficient air and moisture), food (organic matter), and an environment free of harmful chemicals. Beneficial microbes can be added to set the soil food chain into operation by using biostimulants.

6. Measure continuous progress.

A soil health expert must collaborate with your existing technical team to prepare a Biological Scorecard for your farm. This constantly monitors the progress of all the above aspects and enables improvements to be made.

To learn more on how to use practical, sustainable methods to restore and monitor soil health in orchards and vineyards, contact Dr Jan Jacobs on 0845590318 or jan@humefert.com