PlaCoFuGostei, beleza?
Suas plantas tão ficando muito loucas, hein?
Demorei mas achei, dá uma olhada nesse faq do overgrow:
http://www.overgrow.com/growfaq/1111
"Nitrogen (N)
Nitrate - Ammonium is found in both inorganic and organic forms in the plant, and combines with carbon, hydrogen, oxygen and sometimes sulfur to form amino acids, amino enzymes, nucleic acids, chlorophyll, alkaloids, and purine bases. Nitrogen rates high as molecular weight proteins in plant tissue.
Plants need lots of N during vegging, but it's easy to overdo it. Added too much? Flush the soil with plain water. Soluble nitrogen (especially nitrate) is the form that's the most quickly available to the roots, while insoluble N (like urea) first needs to be broken down by microbes in the soil before the roots can absorb it. Avoid excessive ammonium nitrogen, which can interfere with other nutrients.
Too much N delays flowering. Plants should be allowed to become N-deficient late in flowering for best flavor. "
Já vi isso em outros lugares, mas não me lembro bem...
O nitrogênio é sempre necessário, mas em quantidades menores na floração, e o esterco de galinho é extremamente rico em nitrogênio...
Abraço!