Marco Banks wrote:
I wish there were some way to calculate how much N has been kept in the system down through the years by faithfully taking a leak in the orchard. My guess, at this point, is hundreds of pounds of N, with significantly less K and P, although measurable none-the-less. If the NKP of human urine (as it's been reported) is 11-1-2, there are hundreds of dollars worth of free fertility being added to the garden annually.
Jason Hernandez wrote:So, what levels of chlorine residuals are harmful to soil? As with everything, "the poison is in the dose;" a lot of toxic materials occur naturally in trace amounts, and only become problematic when the amounts become too high.
As an example, here are some stats from the City of American Canyon, California:
Substance Units MRDL MRDLG Average Range Contaminant Sources
Chlorine ppm 4.0 4.0 0.68 0.10 – 1.48 Drinking water disinfectant added for treatment
Now, how many of us can translate that into useful information about watering our plants?