I believe for the first time since I've been binge-watching AgPHd videos I may have the answer to "weed of the week": From my 1980s working Summers as a farm-hand West Central Wisconsin farms, and the only thing that looks close to what my mother used to raise in the backyard rhubarb pie, and it not being October where I could see the brown cockle-burrs: My guess is that it's "BURDOCK".

I have a question about this video. You say you can supply the lack of nutrient on the plant by doing a pop-up application during planting, but what happens with what you said in other video about the inminent seed or seedling injury by salts ? What do you recommend to prevent a nutrient deficiency ? A pop-up or a sidedressing application ? I'm asking because i see it a lot on the corn fields i supervise down here in Chile, and farmers tend to think mos of the sinthoms are lack of water.

that soil is straight black