POTENTIAL IMPACT OF BIOENERGY WASTES AS FERTILIZER SUPPLEMENT ON SOIL PROPERTIES.

Wastes materials produced from bio-energy plants such as ash, slurry etc., may be problematic if they are not safely disposed. The wastes utilization as soil amendments is a viable approach as these are rich source of mineral nutrients. Therefore, the present experiment was conducted to evaluate the nutrient release and changes in physicochemical properties of soil after incubation with a different combination of bio-energy residues. Two variants of sugarcane bagasse ash, (A) combustion ash from sugarcane industry and (G) ash from gasification plant were mixed in 1:1 ratio with wheat straw biochar (B) and dairy manure digestate (D) @ 10, 15 and 20 t ha-1. Soil samples were taken after 15, 30, 45, and 60 days of incubation and analyzed for soil physico-chemical and biological parameters. Various amendments significantly influenced the soil pH, electrical conductivity, soil respiration, P, and K contents at each sampling interval. The P and K contents in soil amended with digestate+ combustion ash were significantly increased after 60 days of incubation compared to their initial soil contents. Ammonium contents were increased up to 15 days of incubation and then decreased while nitrate contents increased in the same treatment. While macro-aggregate (77 g kg-1) and organic carbon contents (1.40%) were maximum in biochar + combustion ash treatment. The application of bioenergy wastes improved respiration, soil organic carbon, soil P and K contents. The study warrants that these wastes combinations should be tested under field conditions for further recommendations. [ABSTRACT FROM AUTHOR]