Primary Research on Agricultural Effect of Sludge–Impact of Sludge Application on Crop Seeds Germination and Seedling Growth

Abstract Municipal sludge contains a large number of plants essential nutrients such as C, N, etc., however, pollutants such as heavy metals, pathogenic microbes, organic pollutants being harmful to plants and human also exist in sludge, obviously, sludge has the character like “double-edged sword” if it is used in agriculture. Hence, how to apply sludge into agriculture lands safely has become a focus problem. As first-step research on sludge agronomy effect, a potted plant experiment involved different elements such as plant type, soil type, sludge type and application rate was carried out, aiming at verifying sludge agriculture use value as an agriculture resource to guide effective use of plants nutrients in sludge and confirm the soil bearing value for pollutants in sludge. As result shows, comparing with no sludge dressing treatment, application of dry sludge for trial has no obvious impact on crop seeds germination. Generally, dressing equiponderance sludge promotes different crops seedling growth and seedling biomass increases with sludge application rate increasing. As a conclusion, sludge can be selected as an agriculture resource to provide additional nutrients that plants need, and dressing lime stabilized sludge contributes to improve Red soil productivity more obviously than the other type of sludge, however, the accumulation of sludge application rates should be paid attention for keeping pollutants harm from agriculture environment and food chain.