Anaerobic digestion (AD) for biogas production leads to several changes in the composition of the resulting digestates compared to the original feedstock (ammonia content, pH, carbon to nitrogen ratio, etc.), which are relevant for the plant availability of macro- and micronutrients after field application. Increased NH4+-N content in digested slurries compared to undigested slurries does not guarantee improved uptake efficiency of slurry nitrogen and increased savings in fertilizer nitrogen. AD of crop residues and cover crops leads to an increase in the total amounts of mobile organic manures within the farming system, resulting in a higher nitrogen use efficiency and an increased scope for target-oriented nitrogen application in time and space, when needed by the crop, as an alternative to the site-bound soil incorporation as green manures. AD of dairy manure appears to reduce the fraction of immediate plant available phosphorus and micronutrients. This does, however, not affect short-term crop availability under field conditions. More studies are needed to improve current knowledge on sulfur losses during AD and fertilizer value of digestates.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/elsc.201100085

Effects of anaerobic digestion on digestate nutrient availability and crop growth: A review

Effect of C/N on composting of pig manure with sawdust

Carbon mineralization from organic wastes at different composting stages during their incubation with soil.

One of the most versatile and remunerative techniques for handling biodegradable solid wastes is composting. A large variety of such wastes of plant, animal, and synthetic origins can be gainfully composted, at scales varying from a household bin to a large industry. Compost also has an inexhaustible market as a soil conditioner and fertilizer. Apart from being a source of nitrogen, phosphorus, potassium, and other nutrients for plants, compost is also believed to suppress soil-borne diseases in plants. These virtues make composting an ideal option for processing the enormous quantities of biodegradable solid wastes that are generated in the world. In this article, a review of the state of the art of compost science is presented, encompassing the history, the mechanism, the production, the characteristics, and the effects of composting. It is hoped that this effort would stimulate further interest in composting and in the appreciation of its benefits.

Solid Waste Management by Composting: State of the Art

1 Archaeology, archaeological science and microarchaeology 2 Information embedded in the microscopic record 3 Completeness of the archaeological record 4 Common mineral components of the archaeological record 5 Biological materials: bones and teeth 6 Biological materials: phytoliths, diatoms, eggshells, otoliths and mollusk shells 7 Reconstructing pyrotechnological processes 8 Biological molecules and macromolecules: protected niches 9 Ethnoarchaeology of the microscopic record: learning from the present 10 Absolute dating: assessing the quality of a date 11 Reading the microscopic record on-site 12 Infrared spectroscopy in archaeology

H Kirchmann

Papers

Composting and storage of organic household waste with different litter amendments. II: nitrogen turnover and losses.

Composition of fresh, aerobic and anaerobic farm animal dungs

Composting and storage of organic household waste with different litter amendments. I: carbon turnover