Some plants absorb excess nitrates or oxalates from the soil and store them in plant tissues. Toxicity problems can occur in animals which feed on these plants.
Rooting tonics contain plant growth hormones used to stimulate root growth during plant propagation. They're easy to make at home.
Forage quality of common pasture weeds was determined through laboratory testing to compare feed value of weeds to desirable forage species and nutrient requirements for grazing livestock.