Abstract
Due to the fact that amaranth belongs to type C4 plants, the process of photosynthesis of amaranth differs from other plants. It absorbs carbon dioxide more actively than C3 plants and effectively enriches the air with oxygen. In this regard, decorative amaranth varieties should be used as a natural filter in urban environments with a high carbon dioxide content. In addition, decorative amaranth varieties have a unique leaf and flower shape. The color of amaranth can be yellow, red, green, crimson, three colors; the shape of the leaves is oval, curly; inflorescences are also distinguished by their varied beauty. Soil fertility, temperature and humidity are great importance for the normal development for any plant. In the absence of one of the above factors, the quality of life of the plant will decrease. Lack of nutrients in the soil, unfavorable weather, l ack of moisture leads to inhibition of photosynthesis in plants, a decrease in biomass, and decrease disease resistance. During our research, the sludge of municipal wastewater was used as fertilizer. Slud ge accumulates on landfills as waste, giving off an unpleasant odor and negatively affecting the environment. However, this hazardous waste can be recycled and obtained organic fertilizers for urban landscaping or soil reclamation of disturbed lands. The results of the study showed that 10 t / ha of sewage sludge is the most positive impact on the growth of amaranth, the increase in total biomass, stem length and flower were noted . At this length of the stem of the plant increased by 77%, the length of the inflorescence - in 2.2 times, the mass of inflorescences - in 1.8 times, the biomass of the plant before flowering - in 2.1 times compared to the control.