The effects of heavy metals, ammonia and electrical conductivity in compost derived from swine solid fraction on seed germination and root elongation of Lepidium sativum L.

Phytotoxicity of four different composts derived from swine solid fraction were tested with a bioassay method. The effect of water extracts of compost on seed germination and primary root growth of Lepidium sativum L. was measured. The composts were chemically analyzed to determine electrical conductivity, total N, NH4 + and heavy metals. The percentage seed germination was not affected by the water extracts of composts. The root lengths of all composts were more than 100% of the control (deionized water) throughout the experiment. Electrical Conductivity showed a significant and negative correlation with relative seed germination at the 50% and 75% concentrations. A strong positive correlation was found for water-extractable Cu with relative root growth and germination index at the 10% concentration. Water-extractable Zn showed a high and significant positive correlation with relative root growth and significant but less high correlation with germination index at the 10% concentration.