Application of biofertilizers after biogas production
The use of biofertilizers after biogas production, in comparison with unfertilized organic waste of animal husbandry, makes it possible to obtain yields of agricultural crops 1.5 times higher.
In agriculture, there is a significant potential for the production of electricity and heat from biomass and agricultural waste. Animal waste is a valuable raw material for agricultural production, primarily as a source of organic fertilizers. Industrial livestock – the polluter of the environment, both organic and biogenic elements. It accounts for 43-46% of the total biological load on natural systems.
More than 40% of organic fertilizers of large livestock complexes are transformed into sources of environmental pollution. Continuous use of even processed by the existing traditional technologies of livestock waste leads to the accumulation of nitrates in the soil, its bacterial contamination. All this causes significant material and energy costs for the processing and disinfection of livestock wastes.
In turn, crop production has a significant need for high-quality organic fertilizers. According to the State Statistics of Ukraine, the annual loss of humus in the soil layer of Ukraine reaches 0.66 t / ha.
In accordance with the Law of Ukraine No. 962-15 as amended on June 27, 2015. “On the protection of land”, the basis for reproduction and improvement of soil fertility, other useful properties of the earth, preservation of ecological functions of soil cover and environmental protection.
According to the National Program for the Use and Protection of Land, production of high-quality organic fertilizers is envisaged, ensuring an optimal balance between biological and chemical means of increasing fertility.
The most promising among the directions of utilization of organic waste, especially animal origin, is anaerobic fermentation, which allows obtaining high-quality detoxified bio fertilizers, as well as biogas, as an unconventional renewable energy source.
It has been experimentally established that losses of nitrogen using the existing fertilizer production technologies averagely 24.5%, and when processed in biogas complexes – do not exceed 5%. To obtain 1 kg of the active substance of chemical nitrogen fertilizers, 2 kg of equivalent fuel is consumed. Bacterial sterilization in anaerobic digestion is estimated at 94-98%, deodorization occurs – liberation from unpleasant odor, de-worming – neutralization of parasites in animal waste), as well as a slight decrease in the germination of weed seeds.
The use of fermented organic waste, in comparison with conventional waste, makes it possible to obtain yields of agricultural crops 1.5 times higher. This is due to the best nutritional and sorption properties of biofertilizers. Nitrogen appears in a reduced form and is better absorbed by plants, but for the same reasons, it is necessary to observe the nutritional periods, in order to avoid the oxidation of nitrogen in nitric acid salts and pollution of groundwater.
The organic waste processed in biogas complexes in biofertilizers has a higher content of ammonia compared to primary raw materials, which raises the issue of increased ammonia emission when introducing biofertilizers. With the introduction of biofertilizers in a traditional way – a spreader with a plate machine, the loss of ammonia is 85% greater than when they are locally applied by a rod spreader directly to the ground.
The rates of application of biofertilizers obtained are 0.5-5 t / ha instead of 40 t / ha of traditional composts, and the need for mineral fertilizers is reduced by 20-75%.
Sidorchuk A., Ph.D.