Abstract

Since composts are soil like amendments made from plant and animal remains, they are more important than inorganic fertilizer because they consist of relatively stable decomposed materials resulting from accelerated biological degradation of organic matter. However, little attention has been paid on the use of compost as bio-fertilizers to improve soil structure,  fertility  and  consequently  growth  and  productivity of  plants among farmers in Sri Lanka mainly due to lack of awareness on the beneficial effects. Therefore, the present study focuses on obtaining baseline data set on the efficacy in terms of plant growth characteristics by using different soil compost ratios of different types of composts. Four different types of composts and three different soil compost ratios (1:0.5, 1:1 and 1:1.5) were used in this study. Results of the present study clearly indicated that different composts act differently on the growth parameters tested and showed a reasonable variation with different soil compost ratios indicating both positive and negative effects on plant growth and yield. The results showed that the best soil compost ratio that could be used to significantly improve the growth parameters of Zea mays is 1:1 followed by 1:0.5. From among the different MSW composts used in this study, the best performance was shown by Dikovita followed by Mihisaru Segregated. This study further highlighted that higher ratio (1:1.5 soil compost) of certain MSW composts was not desirable and showed a negative effect on plant height.

Key words:  Aggregate stability, compost, nutrients, phytotoxicity, soil amendment, solid waste.