Influence of Sewage Sludge Compost on the Growth of Plant Stipa capillata Linn. and Plantago asiatica Linn.

On account of sludge compost utilization issue in municipal sewage plant, two types of common perennial herbs in North China Stipa capillata Linn. and Plantago asiatica Linn. were selected, adopting pot experiments to investigate the relations between plant dry weight and nutrient elements utilization rate under sludge compost blending ratio (sludge compost dry weight to soil dry weight) of 0%, 5%, 10%, 15% and 20%, respectively. The results indicate that the soil organic matter, TKN, TP and EC values show increasing trend, and pH shows a slightly decreasing trend with the increase of sludge compost blending ratio. Different plants have different optimum sludge compost blending conditions, with Stipa capillata Linn. and Plantago asiatica Linn. obtaining maximum dry weight under the blending ratio of 15% and 10%, respectively. The SPSS variance analysis indicates that the increment of Stipa capillata Linn. dry weight is obviously related to 5% sludge compost blending ratio and unfavorable with 20% sludge compost blending ratio, while the increment of Plantago asiatica Linn. dry weight is obviously related to 10% sludge compost blending ratio. The nutrient elements absorbed by plants only account for a small part of nutrient elements decrement in soils. The nutrient elements utilization ratio of Stipa capillata Linn. and Plantago asiatica Linn. decreases with the increase of sludge compost blending ratio. With 10% sludge compost blending ratio, the Stipa capillata Linn. nitrogen utilization ratio is 1.76%-6.15%, and the phosphorus utilization ratio is 0.93%-2.57%; the Plantago asiatica Linn. nitrogen utilization ratio is 2.52%-9.13%, and the phosphorus utilization ratio is 3.57%-8.98%.