Research Information System
2nd INTERNATIONAL CONFERENCE ON SCIENCE, ECOLOGY AND TECHNOLOGY, Barcelona, Spain, 14 - 16 October 2016, pp.857-867, (Full Text)
Sewage sludge is the end product of waste water treatment plants. Due to its high levels of organic matter and plant nutrients, this material is potentially useful in crop production. This study investigated the effects of dried and stabilized sewage sludge on the yield and nutrition of bermuda grass (Cynodon dactylon L. Pers) that was grown on two types of soils containing different levels of lime. In the pot experiment, bermuda grass was grown for 16 weeks in growing medias using two soils containing 8 % (CS1) and 19.4 % (CS2) lime. Sewage sludge was applied to these medias doses of 0 (SS0), 0.5 (SS0.5), 1 (SS1), 2 (SS2), 4 (SS4), 8 (SS8) tones da-1
The effect of sewage sludge on growing media pH was not significant; but, EC and organic material levels had increased. The average organic matter content increased by 26.38 % at SS4 while it increased 37.7% at SS8 compared to the control (SS0). On both soils, the lowest P, K, Ca, Mg, Na concentrations in growing medias were determined at the SS0 applications; the sewage sludge treatment has increased the concentration of these elements. When evaluated according to the SSXCS interaction, the growing media which was prepared by applying sewage sludge to the CS2 soil, showed higher concentrations of total N, P, K, Ca and Mg than the CS1 soil. The Na concentration, however, was determined lower.
Due to the sewage sludge applications, the shoot dry matter yield steadily increased. While the average shoot dry matter yield was 4.01 g pot-1 at SS0, it reached 69.15 g pot-1 at SS8. The shoot dry matter yield in SS4 X CS2 and SS8 X CS2 was respectively 62.39 and 62.65 g pot-1 and it was not statistically different. The highest shoot dry matter yield was obtained from SS8XCS1 as 75.65 g pot-1. Depending on sewage sludge applications, the N concentration of shoot had increased and the highest value was determined in the SS8XCS2. The shoot P and Ca concentrations increased with the application of sewage sludge to CS1, but decreased with the application to CS2. However; shoot P and Ca concentrations of plants grown in CS2 were determined higher than plants grown in CS1. Sewage sludge application increased the shoot K concentration where the highest values were obtained at the SS4XCS2. The shoot Na concentration increased depending on the applications of sewage sludge and highest values were obtained in the applications SS8XCS1 and SS8XCS2. The applications didn’t affect the shoot Mg concentration.
As a result, sewage sludge provided to have positive effects on the soil organic matter and nutritional content. Compared to the control plant, it caused an average 12 -fold increase in dry matter yield by improving the quality of nutritional intake with basic macro plant nutrient elements. In spite of these positive results, effect of sewage sludge on soil salinity should be taken into account to prevent any salinity problem in long-term application to soils.