Agronomic Characteristics of the Compost-Bedded Pack Made with Forest Biomass or Sawdust

Abstract

To ascertain the agronomic value of the material resulting from the compost-bedded pack (CBP) in dairy barns, a cross-over experiment was designed with eight dry non-pregnant Holstein cows. The study was performed in two 11-week periods. Bedding materials used were: (1) CBP with sawdust (S) and (2) CBP with forest biomass (FB). Samples were taken from the raw bedding materials and from the CBP across the experiment. We conducted an additional study preparing two piles, one of each CBP material, to accomplish a composting process of 3 months, where samples were also taken. Granulometry and some chemical composition characteristics of FB made it a suitable bedding material to be used as CBP, but its high moisture content limited the ability to absorb liquid manure. Both the degree of stability of the organic matter and the temperature evolution of CBP suggest that a real composting process did not occur. Finally, the composting process of the piles did not lead to any relevant change in CBP materials. From the agronomic point of view, S and FB present potentially valuable characteristics as regards organic amendment in the soil, thanks to their high organic matter content and low nutrient content.

A Composting Bedding System for Animals as a Contribution to the Circular Economy

“…The high material costs of the wood by-products and straw due to competition from bio-gas and other industries adversely affects the economic viability of the system. Accordingly, exploration of cheaper by-products and waste products will be of increasing interest [11,14,31].…”

“…The composting process is affected by the temperature and moisture content of the bedding, as well as the ambient temperature and humidity [4]. In temperate climates, maintaining adequate conditions and a proper composting process in the bedded-pack to achieve a stable humus-like end-product, especially during the winter, can be a severe challenge [5,14,22].…”

“…An important benefit of composted bedding material is as a source of organic matter and nitrogen fertilizer for the soil [14,26] as illustrated in Figure 10. Although compost is known to improve the soil structure and bioactivity, the composting process is more complicated than generally appreciated.…”

“…Although compost is known to improve the soil structure and bioactivity, the composting process is more complicated than generally appreciated. When the composting of bedding materials was experimentally simulated in trials of three months duration, the stability of the organic matter did not indicate real evidence of composting [14]. Further, some farmers have claimed an increased ash content (nonorganic matter) of grass samples harvested from compost treated swards [27], but this was not observed in the survey of the farmers described above (Table 1).…”

“…Compost production experiments in catering companies dealing with food waste [13], as well as agronomic characteristics of [14] and gaseous emissions from the CBP materials [15] were studied in view of circular processes. To our knowledge, no study has been reported linking CBP as a holistic system to the circular economy.…”