Of course, corn plants are different now, yields are higher, GMOs are a regular part of conventional corn breeding, there is even some natural resistance to insects or disease we never had. But there are also some unintended consequences that researchers are just now discovering.
A research report published in March of this year is eye-opening especially for those in organic agriculture. Basically, what these researchers did was to study if the corn breeding program have altered the recruitment of microorganisms to the rhizosphere of plants over time and with changes to the plant genotypes.
In as simple a language as possible they looked at 20 corn lines spanning the years 1949 to 1986. This is the time when great advances were made in corn genetics, and they corresponded with the introduction of synthetic nitrogen into the corn production system. What they were looking to investigate was whether the breeding program, conducted with plenty of nitrogen, bred superior corn yielding varieties, but without the necessary tools to recruit the rhizosphere microbiome that helps the corn plant to transform atmospheric nitrogen into nitrogen necessary for growth.
Past research has proven that plant microbiomes play a major role in altering plant resilience, fitness, nutrition, and productivity. Plant hosts selectively filter microorganisms that colonize their rhizosphere, and this selection ability is inherited (or not) across the crossbreeding process. So, if the breeders were only looking at yield, and they had plenty of nitrogen, then they may lose this beneficial rhizosphere microbiome recruitment process.
Okay, lots of information to take in, but the takeaway is – when we use varieties (possibly any crop) that has been developed for modern agriculture, that uses synthetic crop inputs, they will probably struggle in an organic system. I do believe that conventional crop breeders will be looking to fix this issue, especially with high nitrogen prices, but it only emphasizes a need to have organic crop breeding programs that understand and use the plant/soil/microbiome interactions in plants.
If you would like to see the entire research report, “Maize germplasm chronosequence shows crop breeding history impacts recruitment of the rhizosphere microbiome,” just click the button below.