The Impact of Treated Coal Waste Sludge on Paddy Soil Chemistry Rice Growth

Mud from the coal washing pond, treated with lime, has spilled multiple times, resulting in pollution of the rice fields and sparking conflicts between local farmers and coal miners. The focus of this study was to determine the chemical properties of paddy field soil mixed with mud, chicken manure compost, and its effect on rice plants. The research was conducted in a greenhouse using a complete random design with a 3x4 factorial and three replications. Rice was planted in a bucket containing 10 kg of soil treated with water. This study using three levels of chicken manure compost (P), designated as P0 (0 g), P1 (50 g) and P2 (100 g). The soil mixture was comprised of four levels of mud (L) and paddy field soil (S), designated as M0 (0 kg L + 10 kg S), M1 (2 kg L + 8 kg S), M2 (4 kg L + 6 kg S), and M3 (6 kg L + 4 kg S). Through a series of tests, it was found that this treatment had a positive impact on the chemical properties of paddy soil, with a notable decrease in soil acidity (pH of 5.2 to 6.2), an increase in total nitrogen (0.17% to 0.37%), and an enhancement in total phosphorus (P2O5) and potassium (K2O) levels (24 to 55 ppm and 43.3 to 72.87 ppm, respectively). The control treatment (P0M0) exhibited a pH of 4.5, a total N of 0.16%, P2O5, and K2O of 18.0 ppm and 41.50 ppm, respectively. During the generative phase, the application of sludge and compost separately resulted in a significant effect on plant height at 60 days after treatment (DAT). However, the interaction between the two treatments was not significant. The generative phase of P1M3 interaction exhibited the fastest flowering, with a duration of 53 days, which was 6 days faster than the control. The separate compost treatment exhibited a duration of 3 days, which was 3 days faster than the control. Also, the mud treatment did not yield significant results. Additionally, for panicle length, all treatments exhibited no significant differences. The weight of dry seed contents of panicles exhibited a significant difference between the interaction and the control. The highest yield of P1M3 was 5.33 g, while the control exhibited a yield of only 2.12 g. These results confirm that the treated coal waste sludge spill had no negative effect on paddy rice, on the contrary, it reduced the acidity of paddy soil at the optimum level of macro and micro nutrient availability. The addition of a 50 g compost dose and 1.5 times the weight of sludge to paddy soil significantly accelerated flowering in the best rice plants, P1M3, and increased yield by 2.5 times compared to the control group. These findings have changed farmers' perceptions regarding sludge spillage, which they previously viewed as a pollutant in their paddy fields.