Field Science Goes Anaerobic in 2011

The growing importance of energy harvested from anaerobic digestion plants in the UK has created a disposal problem. The liquid and semi-solid waste streams generated by anaerobic digesters are very bulky and not particularly effective as fertilisers, although the amount of organic matter they contain has potential for agriculture, because organic matter is an important component of a healthy soil and modern farming methods have depleted OM levels in arable soils. However, the problems posed by digestates are twofold:

a. Because of their bulk, it is not cost-effective to transport digestates very far. This can lead to over-application on local farms and means that needy soils further afield go without.

b. The NPK and micronutrient value of raw digestate is limited, which makes it difficult to market them as a substitute for conventional fertilisers. A farmer's attitude tends to be "I'll have it if you are giving it away".

The use of digestates is a great opportunity to reduce the energy footprint of UK agriculture, 47% of which is caused by the manufacture, distribution and use of synthetic fertilisers. Field Science expertise is in optimising nutrient availability to grass, livestock and crops and we have already identified many sources of essential nutrients, some formerly regarded as wastes, some as by-products.

Field Science Consultants have been contracted, over the next two years, to create sustainable, soil-improving, slow-release fertilisers from digestates that will contain the full spectrum of nutrients and be less bulky than at present.

Never forget that at present we effectively throw away 70% of the fertilisers we buy because our NUE (Nitrogen Use Efficiency) in the UK is only 30%. In simple terms, for every £10,000 pounds spent on nitrogen fertilisers, £7,000 worth either slips below the rootzone or volatizes into the atmosphere! We aim to create fertilisers with staying power.