Reducing greenhouse gases from agriculture by integrating food and energy in livestock based farming systems

Food and energy production from biomass in smallholder farming systems with a negative carbon footprint;
T R Preston, Finca Ecologica TOSOLY, Socorro, Colombia

On 30 August 2012 at the World Water Week Conference in Stockholm, President of Nestlé, Peter Brabeck-Letmathe said: “The production of bio-diesel puts pressure on food production through the use of land and water that would otherwise be used to grow crops for human or animal consumption. Biofuels are only affordable due to high subsidies they receive, especially in the U.S. It is absolutely unacceptable and cannot be justified to convert food into fuel”. On 13 September, Reuters reported that: “The European Union will impose a limit on the use of crop-based biofuels over fears they are less climate-friendly than initially thought and compete with food production”.  These recent statements put into perspective the debate about the wisdom underlying the policies being promoted in rich countries to replace imported petroleum products with bio-fuels derived from forms of biomass that are also the primary source of food for people and feed for animals. There is no shortage of solar energy as the sun provides Earth with as much energy every hour as human civilization uses every year. This is therefore the opportunity as well as the challenge to save the planet from the inevitable collapse that will occur at some point in the future if human-derived activities continue at present rates. The strategy should be clear to everyone; this is to utilize all forms of solar energy capture – wind, waves, tides, biomass and solar panels. This paper will discuss the options available from appropriate use of biomass to produce both food and energy in systems that are synergistic, rather than conflictive, as well as being friendly to the environment.

Manipulating microbial habitat and electron sinks to mitigate methane emissions from integrated animal production industries;
R A Leng, University of New England, Australia

The physical characteristics of fiber have a major impact on the rate and efficiency of digestion of feed in the rumen, Creating microbial habitat by chopping roughages or treating them with alkali  and other physical disruptions of the surface epithelial layers have shown how important surface area is  for bacterial attachment and  biofilm formation, which determine the rate and extent of  solubilisation of the heterogeneous substrate available to microbes. Supplying in the feed additional microbial habitat by including inert particles with a large surface area relative to weight, is potentially a way of providing habit for in particular those syntrophism organisms that are at the extremes of organic matter breakdown including methanogenic Archae and potentially microbes that reduce both nitrate and sulphate, which are also biofilm components and terminal electron acceptors that have been successfully used to significantly lower enteric  methane production

Biochar in the influent to biodigesters improves the rate of gas production and, when reacted with biodigester effluent, adsorbs nutrients enhancing its value as soil ameliorating agent;
Sisomphone Southavong,  Champasack University, Lao PDR

Biochar is the product derived by heating fibrous biomass at temperatures exceeding 600°C in limited supply of air. Its important characteristic is the surface area per unit mass which is in the range of 20 to 3000 m²/g depending on the method of processing. It is thus an ideal agent for formation of biofilms supporting consortia of microbes active in the conditions set by the substrate and the media in which it is being fermented. This presentation will describe the use of biochar (derived from the gasification of rice husks) as a soil ameliorating agent, and as an additive in the influent and effluent of biodigesters.

Biochar reduces enteric methane production and improves growth and feed conversion in cattle;
Sangkhom Inthapanya, Southanouvong University, Lao PDR

Results will be presented for: (i)   methane production when biochar (derived from gasification of rice husks in an updraft gasifier stove) was added at 1%  of the substrate DM (mixed cassava root and leaf meal) in an in vitro  rumen incubation; and (ii)  live  weight gain, feed conversion and enteric methane production in local “Yellow”  cattle supplemented with biochar at 1.5% (DM basis) of a diet of  ad libitum cassava root chips and fresh cassava foliage restricted to 10 g (DM) per kg live weight.

Biodigesters and biochar to produce energy and reduce pollution from cassava starch processing;
Duong Nguyen Khang, Nong Lam University, Vietnam

Factory scale processing of cassava roots for starch extraction produces waste flows which are highly polluting. This presentation will describe technologies for reducing pollution by recycling the wastes: (i) through large scale biodigesters (washings from the factory); (ii) by gasification (the root peelings); (iii) filtration through biochar of the final waste streams; and (iv) by ensiling for animal feed (the solid waste after starch extraction).