Abstract:
The utilization of biogas slurryr, a by-product of anaerobic digestion, has gained significant
attention for its potential in sustainable agriculture. This study focuses on evaluating the
chemical composition, particularly the nitrogen (N), phosphorus (PzOs), and potassium
(KzO; levels, of biogas slurry produced from a mixture of cattle waste manure and dairy
by-products, including waste mitrk and yogurt. Additionally, the study investigates the
impact of incorporating mango wood ash into the slurry at various ratios.
The study employs a weighted average approach to calculate the resultant chemical
composition of the slurry-wood ash mixtures. At a2:l rctio, the pH increased to 8.07, with
N, PzOs, and llzO levels reaching 0.040033%,0.95yo, and0.4l2%y respectively. The 4:l
ratio yielded apH of 7.68, N at 0.39%, PzOs at}.2l%o,and KzO at0.28o/o.The 1:0.15 ratio
resulted in a pH of 7 .478,N at 0.24o/o, Pzos at 0.018yo, and llzo at 0.r9o/o.
This study contributes to the body of knowledge on the use of biogas slurry as an organic
ferlllizer by demonstrating how the addition of wood ash can significantly alter its
chemical properties. The findings highlight the potential of biogas slurry enriched with
dairy by-products and wood ash to enhance soil fertility and support sustainable
agricultural practices. Moreover, this research underscores the importance of optimizing
the ratios of slurry to wood ash to achieve desired nutrient levels, which can vary based
on specific agricultural needs.
In conclusion, the integration of waste milk, yogurt, and wood ash into biogas slurry offers
a promising approach to recycling organic waste and improving the nutrient profile of
organic fertilizers. Future research should focus on long-term field studies to assess the
agronomic benefits and environmental impacts of using such enriched biogas slurry in
various cropping systems.
