The champions of the "soil food web" methodology have done well to show us that a better understanding of soil biology and "working with the soil rather than against it" is the wave of future agriculture. Farming practices are increasingly being influenced by consumer demand, banning of older environmentally damaging chemistries, mandated water quality standards, and the introduction of newer organic agricultural methods and technologies that provide benefit for soil biology rather than the disruption of natural soil/plant processes.
"Old agriculture" is intensive, requires a lot of fertilizers and pesticides, disregards soil health, produces decreasing crop yields over time (even with increased usage of chemicals), as well as declining crop nutrient values. Studies have shown that the nutrient value of various crops has declined significantly since the 1940's when agriculture was first introduced to using these chemicals for commercial farming.
Organic agriculture focuses on improving soil biology, which utilizes in practice; soft chemistries, organic soil amendments (to increase biology diversity and levels), no till (to avoid disruption of biology), precision farming and automated irrigation (to maximize production potential), and overall reduction of field applied input materials (which reduces material and labor costs). Well balanced and diverse soil biology makes the "locked nutrients" already in the soil "plant available", so less input materials are required as the soil's biology develops.
Soil biology is very complex and still largely not well understood, however this is changing rapidly. Studies are showing that instead of disrupting the soil, much better results can be achieved by complementing natural processes. Plant Growth Promoting Rhizobacteria, or PGPR, are proving to be of great importance as part of soil biology diversity. These microbes reside on the surface of roots and work symbiotically with host plants. PGPRs comprise of the bacterial species of Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Arthrobacter, Burkholderia, Bacillus, and Serratia, which are all beneficial to enhance plant health, plant growth, and yield production. These microorganisms are nourished by the host plant through root exudation, and in turn produce lipopeptides/bio-surfactants that inhibit the growth of phytopathogens, siderophores that chelate iron, enzymes that are essential organic catalysts for molecular activity and, finally, Systemic Induced Resistance or SIR elicitors that activate the plant’s own defensive mechanisms.
Rhizobacteria reduce the need for chemical fertilizers. Part of this is due to the plant’s use of ionophores which are produced naturally by a variety of microbes. Ionophores are molecules that act as shuttles for particular ions across the lipid membranes of plant root cells without expenditure of energy, which provides "free transport" for the uptake of nutrients.
Nurturing the soil (which in turn nourishes the plants) begins with rebuilding diverse soil biology. This includes using organic soil amendments, plant extracts (such as seaweeds and yucca), and a regular implementation and deployment schedule of good compost tea. These materials are key to building soil and plant health and reducing plant diseases. OASCO carries an array of premium organic input materials and compost tea blends that produce results that growers can count on.
We’re committed to Improving Agriculture from the Ground Up and are always available to talk to you about our products and recommendations.
(Content originally published on the Organic AG Supply Company Blog - January 2019)