Hygienization assessment during heap co-composting of Turkey manure and olive mill pomace

Abstract

Article InfoThis study aimed to investigate the co-composting time effectiveness as well as the effect of the initial Carbon/Nitrogen ratio (C/N)i variation on the hygienization of olive pomace and turkey manure. Six different heaps, at 3 levels of (C/N)i ratios: 20, 22 and 28, were installed and monitored during 6 months and assessed at three steps: At the beginning, the end of thermophilicphase and the end of curing-phase. The microbial monitoring concerned 5 microbial pathogens contents, used as hygiene microbial indicators, namely: Sulphite-Reducing Anaerobes (SRA), Escherichia Coli (E. Coli), Total Aerobic Mesophilic Flora (TAMF), Staphylococci, and Salmonella spp. Initially, the mixtures showed high TAMF and Staphylococci loads. Meanwhile, SRA and E. coli populations were relatively low and Salmonella spp. was not detected. The microbial assessment showed a significant effect of composting time on the reduction of pathogens load, except for SRA where its population has increased significantly, while the (C/N)i had a non-significant effect on pathogen content of the end-product. The final values expressed as colony-forming unit per gram (CFU g -1 ), were as follow: Sulfite-reducing Anaerobes (≤3.1 x 10 3 CFU g -1 ), E. Coli germ used as an indicator of faecal contamination (<4 x 10 1 CFU g -1 ), Total aerobic mesophilic flora (≤1.4 x 10 6 CFU g -1 ), Staphylococci (<10 CFU g -1 ) and non-detection of Salmonella spp. Finally, the seed germination tests were carried out on three different seeds: lentils (Lens culinaris), barley (Hordeum vulgare) and durum wheat (Triticum turgidum) showed that the use of the compost extract is favourable for seed germination with germination index (GI%) values exceeding 85%. These results confirm the non-phytotoxicity and maturity of the composts.

Effect of carbon to nitrogen ratio and aeration rate on phosphorus and exchangeable cation contents and their leaching in the soil during olive pomace and turkey manure co-composting

“…On the other hand, agricultural livestock and agri-food intensification produce large quantities of organic wastes which can lead to environmental pollution and compromise the sustainability of agricultural production [11,22]. Furthermore, organic waste, whether animal or plant matter, is a potential source of organic matter and plant nutrients [3,6]. Moroccan biowaste has been estimated by El-mrini et al [23] at 34.7 million tons a year, while Azim et al [11] have concluded that there is a potential for organic waste estimated up to 1 million tons of dry matter a year, and 13 million euros worth of N, P, and K that can be recovered from the horticultural wastes, only in the Souss Massa region in the south of Morocco.…”

“…Turkey livestock activities had significantly increased in Morocco, which led to a rise in turkey manure generation. Turkey manure composting is a suitable technology able to recycle nutrients, prevent greenhouse gas emissions, and supply nutrients that can improve soil fertility and enhance crop yields [3,32,55]. Another sector that constitutes a source of potential pollution is olive oil production, which has experienced an important development following the implementation of the Green Morocco Plan in 2008 [12].…”