Innovative Solutions to Old Problems

The Nitrates directive, the Water framework directive, complying with these, how to combat global warming, how to generally care for the environment, while maintaining a competitive agriculture sector even without chasing, some would say unrealistic goals, of food harvest 2020 are issues that farmers have to continually grapple with.

In the context of this, last week I was part of a highly interesting trip to Kumac Mineralen, a manure treatment plant in the Netherlands. The Kumac Mineralen livestock manure treatment system is part of a pilot project financed by the Dutch Government and undertaken by Wageningen University, with the purpose to investigate the possibilities for total removal of organic compounds from livestock manure, and thus have end products with characteristic comparable to those of mineral fertilisers.

The Netherlands has the highest livestock density in the EU, equal to 226 kg organic N per ha agricultural land. The situation can only be maintained due to re-distribution and processing of the livestock manure, and because the Netherlands were granted a derogation from the Nitrates Directive, which is also the case for certain sectors in Ireland, so that the spreading of livestock manure can be as high as 250 kg N per ha on cattle farms that use grazing, under strict conditions which are specified in the derogation decision.

Kumac Mineralen receives around 70,000 tonnes of pig slurry annually from 43 farms in the region. The liquid manure is reduced in volume by 50% and in a four-stage procedure, clear water, liquid fertiliser concentrate and valuable solid matter are extracted from the source material.

The end products are:

  • Roughly 50% of input amounts come out as purified water, which can be discharged in nature – Kumac Mineralen has on basis of analyses been allowed to dispose the water in nature by the Dutch environmental authorities.
  • Approximately 30% of input amounts come out as a liquid fraction holding 7-12 kg N and 7-10 kg K per tonnes. Kumac Mineralen is marketing this liquid end-product under the name Fertraat.
  • Almost 20% of input amounts come out as a solid solids fraction with 28-32% total solids, and holds almost all of the phosphorus in the livestock manure coming into the system. Kumac Mineralen is marketing the separation solids as a product called Fertex, which they claim is comparable to a 12-17-5 NPK fertiliser.

As Ireland commences the process in 2017 of renegotiating our derogation from the Nitrates Directive (to run from 2018 to 2021), we can learn from this type of innovation and while it may take significant initial capital investment there is long-term benefits to be gained. From an environmental perspective, the benefits are direct and obvious; there are also economic benefits to farmers in making full and targeted use of a valuable fertilizer source as opposed to buying in expensive chemical fertilizer, which are energy intensive in themselves to produce.

AgriculturePaul Cotter