Processing of chicken manure of different ages by modifying the basic technology into bio-compost and testing it on potatoes

Abstract

Features of the development of an algorithm for preparing new biocompost from manure of different ages under controlled conditions are presented. An impressive series of preliminary experiments with composting manure in various combinations, both with and without the addition of sawdust, allowed us to select the best process for solid phase aerobic fermentation (SPAF). A process was chosen for which the initial mixture is made up of rotted (from 2 years) and semi-rotted (from 6 months) droppings in a ratio of 3:1 with the addition of 10 % sawdust, while an optimal temperature regime is created in the fermentable mass. This fermentation process was accompanied by the expected losses of carbon and nitrogen, reflecting the actually natural processes of biocomposting in the piles. Oxidation of the components of the fermented mass occurred, as evidenced by the intensive increase in nitrate accumulation against the background of a decrease in ammonia nitrogen. The new biocompost was characterized by a fairly high content of basic nutrients,  %: Nt_otal - 3.80, P₂O₅ - 2.1, K₂O - 2.45, humidity - 55 %, slightly alkaline pH 8.5. A negative, difficult to eliminate consequence of the updated SPAF process is the unpleasant odor of biocompost, the reduction of which can only be achieved through prolonged ventilation, which undoubtedly increases the cost of production. The initial testing of the new biocompost in 2023 on potatoes of the Queen Anna variety at an application rate of 15 t/ha ensured an increase in its yield compared to the control (without fertilizers) by 87 %. The new biocompost is recommended for use as a safe organic fertilizer and as a component for the production of soils. The benefits of this type of SPAF are associated with the abandonment of an expensive ingredient - peat, the use of a cheap livestock by-product (poultry manure) to the maximum extent, as well as the introduction of forest processing waste (sawdust) in a very small volume into the initial mixtures.