I'm not picking on you or being sarcastic, just curious what new science I'm missing. What biosciences can be applied to eliminate the need for chemicals to kill weeds? I have farmer friends trying to deal with marestail in notill soybeans who are all ears.
Great question, and the discussion I wish we'd be having across the whole internet.
First, take farmers outta the discussion. Those guys have constraints that don't bind us: profit and harvest-ability.
There are no weeds, only misunderstood plants. Anything growing on the landscape is an expression of what's needed. Unkillable zombie weeds are first responders after a disaster, and we're shooting at them with chemical and iron while they try to do their jobs. The worst of the weeds follow the worst of management to rectify what we've done to the soil. Plant life evolves with what is going on in the soil. First the horrible, then it weakens and other stuff begins to fill in. Eventually it turns back into what it was before us.
My whole contention is that the closer we get to whole-system/whole-health management, the first responders will quit coming. I'm convinced now more than ever that clover has to be the canvas to any plot system we have. But you can't just have clover. You'll lose it to grass and broadleafs in a few years. Spray as you may, it'll thin and weaken and something we can't kill will inevitably take over to un-do what we've done.
For me, that was horsetail, and curly dock. I sprayed to kill sedge, and it touched off a crop of horsetail that completely shaded the ground. Imagine that for a second, a plant with no leaves so dense it shaded the ground. I've also replicated that feat with horsetail and thistle as illustrated below. That was the last time I used glyphosate because I had no plan B after plan A resulted in catastrophe.
The closer we can get to a balanced plant community in the soil, the fewer management issues we'll have. That's where I'm at today. Any new plot almost has to start with rye, white clover, and chicory. It's the cornerstone of a balance that mimicks nature, but is still extremely simple. Think of it as a city economy. If all you had were military blowing things up, and nobody to rebuild and produce, that economy would collapse. You have to have carpenters, doctors, electricians, growers, teachers, bakers, women wrestlers, firemen, cooks, cleaners, mechanics, welders etc.
Native plant communities consist of grasses, legumes, broadleaves, flowers, fungus, bacteria, bugs, bees, nematodes, worms etc. They all play a part. Every one of them exists to do a job, and every one serves as a food source for another. Clover feeds AMF. AMF builds a grid that connects all plants beneath the soil. Along that grid, plant root exudates are used and traded by the fungus for exudates from the other plants.
Bacteria that consume (tie up) nitrogen are eaten by nematodes and pooped back out as stable and soluble N. Flowers above ground draw in predators that will eat other predators that would seek to defoliate a mono-crop planting. Worms dig channels, solubilize minerals, and kick out castings that aid soil flocculation which enables water holding capacity and movement into the subsoil vs ponding or running off. Glomalin is produced in functioning soil that holds particles and nutrients together so the soil pores don't collapse and sever the fungal nutrient trade network.
What is all boils down to is picking your weeds. Pick them yourself or nature will pick for you. It's figuring out how to manipulate a system like this that is tougher, but worth figuring out. This year I was able to get barley, jap millet, soybeans, and some flowers going in my clover plot by simple throwing and mowing as soon as the soil warms. It was a nice leap forward, but there is work to do. My barley planting was far too thin, and my sorghum didn't do well. I went way to light on seed rates. I'll adjust and try again next year. Most importantly, I knew if I failed, I would still have a clover and chicory plot. That will buy me some time to adjust and work back towards balanced before the long drain of imbalance brought me something I didn't want.
I was flattered as hell when I heard Dr. Nichols echo these same words. If you have time, watch the whole video. If not, just watch a minute or so from the 57:48 mark.