International Academy of Ecology and Environmental Sciences Proceedings of the International Academy of Ecology and Environmental Sciences 2220-8860 5 2 2015 06 1 Diatomite and re-use coal waste as promising alternative for fertilizer to environmental improvement 70-76 EN Mohammad Hassan Sayyari-Zahan AbdolHamid Gholami Somayeh Rezaeepour http://www.iaees.org/publications/journals/piaees/articles/2015-5(2)/diatomite-and-re-use-coal-waste-for-fertilizer.pdf> Application of conventional fertilizers has been contributing much pollutant to the environment. This study aimed to assess the potential of diatomite and re-use coal waste as a non chemical fertilizer to environmental improvement. The experiments were evaluated in 2kg pots under greenhouse conditions at 4 levels of diatomite powder including 0, 10, 20, 40 g/kg soil as well as 5 levels of coal waste powder including 0, 20, 40, 80, 160 g/kg soil based on completely randomized design with three replications. Treatments of diatomite and coal waste were mixed well and kept under field capacity moisture for 4 months. The results showed that the effects of diatomite and coal were significant on EC, K and P concentrations in soil while the coal waste showed more influenced on decreasing of soil pH. Adding diatomite up to 40 g/kg in soil increased EC, K and P viz. 2.92, 1.19 and 1.54 times respectively compared to control sample. Using of 160 g/kg of coal in soil increased EC (2.89 times) and decrease pH (1.06 times) which had led to increased availability of trace elements that enhance plant growth. The highest bio-available concentrations of K and P in soil obtained at 80 and 40 g/kg of diatomite and coal waste respectively. This study demonstrates that a good fertilizer can be produced by using diatomite and coal waste; however, further research is required.