The Effect of Locally Fabricated Pelletizing Machine on the Chemical and Microbial Composition of Organic Fertilizer

Abstract

In order to make organic fertilizer more quantifiable and attractive to farmers, a pelletizing machine was fabricated locally to produce pellets from powdery fertilizer. However, concerns have been raised on the potential impacts this process could have on the quality of organic fertilizer. An experimental study design with laboratory analysis was adopted. The study took place at Alesinloye market solid waste recycling complex, Ibadan Nigeria, in April, 2012. Samples of both powdery fertilizer and pellets were collected for chemical analysis. Total bacterial count was also determined in the laboratory. The results were subjected to student t- test statistics to compare the means. The variations in the levels of N (2.14 ± 0.02%; 2.39 ± 0.01%), C (37.19 ± 0.01%; 39.25 ± 0.01%), Na (0.1 ± 0.01%; 0.12 ± 0.01%), Ca (1.09 ± 0.01%; 1.16 ± 0.02%) and all heavy metals analyzed:  Mn (123.50 ± 0.50 mg/kg; 131.50 ± 0.50 mg/kg), Fe (2,083.00 ± 8.00 mg/kg; 2,135.50 ± 1.50 mg/kg), Cu (224.50 ± 1.50 mg/kg; 238.00 ± 1.00 mg/kg), Zn (305.00 ± 1.00 mg/kg; 330.00 ±1.00 mg/kg), Pb (13.75 ± 0.15 mg/kg; 15.70 ± 0.10 mg/kg), Cd (0.82 ± 0.02 mg/kg; 1.08 ± 0.02 mg/kg), Ni (6.68 ± 0.02 mg/kg; 7.12 ± 0.02 mg/kg), and Cr (7.88 ± 0.03 mg/kg; 8.81 ± 0.01 mg/kg) for pellet and powdery fertilizers respectively was significant (P =.05). The microbial count was significantly lower in pellets than powdery fertilizer. It is evident in this study that pelletizing improved the quality of organic fertilizer due to the significant reduction of heavy metals and bacterial. Though pelletizing significantly reduced the levels of major nutrients as well, the effects were minimal as the pelletized fertilizer still fulfilled the standards organic fertilizer requirements. It is therefore recommended that organic fertilizers should be pelletized before their usage.