Proper plant nutrition is important, here are some common sources here.
The idea is simple. Plant an extra row of vegetables, and donate the harvest to your local food bank or shelter.
Manure, Seabird (Peruvian)
Micronutrient values may show a zero value for missing data. Over time the dataset will improve, but keep in mind that in some instances; especially with natural materials, the listed values given are rough estimates and will vary with samples from different sources.