Biological farming could bring benefits

By Josephine Scamell, independent consultant, Ground Level Nutrition

Cost savings are always high on the agenda for any farm business, but over the next decade we are likely to see this concept taking on a whole new dimension.

Intelligent application of biological agriculture could bring environmental benefits and carbon footprint efficiency, while exploiting natural farm waste products. Enhanced nutritional performance could also be gained while toxic waste products are microbially digested on site.

It is only relatively recently that dairy farmers have started to look into the bio-digestion or enzyme treatment of slurry. As artificial fertiliser prices continue to climb it is becoming increasingly obvious farm yard manure (FYM) and slurry need to be used more effectively.

FYM and slurry use

Over the past few years more farms have been replacing artificial fertiliser with home-produced slurry. However, nutrients need to be applied in the growing season to complement grass growth in the most efficient way. But raw slurry or un-degraded FYM compromises the palatability of grazing swards and also risks silage clamp contamination in cutting forages.

Apart from the practical inconvenience of trying to graze unpalatable swards, it is not realistic to expect livestock to feed efficiently on contaminated forage. Health issues and poor forage intakes result in reduced growth rates or milk yields and can detract from any perceived advantages of fertilising with slurry.

Practical, physical management such as slurry injection can offer a solution in some situations, but is often problematic or expensive. A trailing shoe or dribble bar system is often thought to be a good compromise, but there is still some level of sward contamination.

Looking at the raw material itself could provide the answer. If it was possible to replace noxious slurry or dirty water with a non-toxic bio-available nutrient liquor, we would benefit from a higher grade bio-fertiliser product and reduce problems with sward rejection.

Providing bio-available nutrients to the growing crop would offer more efficient use of a resource while significantly reducing environmental contamination risk. The bio-slurry would also be soil friendly and help promote valuable earthworm numbers rather than harm the soil – a benefit that should not be under estimated.

Slurry additives

There are several slurry digesting products available on the market. Independent research is on going to help evaluate the benefits. Initial trials are indicating a 30% improvement in N, P and K values on treated slurry. This will usually offer a fertiliser saving more than sufficient to justify the cost of the product, which is likely to range from about £4-8 a cow a year.

Practical benefits include digestion of the slurry lagoon crust and presentation of a more physically even liquefied product saving time and money on agitating/stirring the lagoon and spreading. As a result of aerobic breakdown of the slurry, the odour is also significantly reduced.

The resulting forage is likely to be better in terms of nutrient balance – historically there have been problems with typically high potash levels in slurry resulting in high potash forages. An improved nutrient balance between sodium:potassium is evident in trial work and will pass on another benefit to livestock consuming the forage. The microbial digestion of the slurry is also likely to present a more balanced trace element profile to the plant, via the soil.


Historically, there was a wealth of knowledge and skill in the art of composting. Today, many farmers, particularly organic, have been given the incentive to lead the revival with a modern twist.

According to research from the USA, the value of compost versus undegraded FYM is significant. As a starting point the value is at least 10 fold. The benefits are initially focused on N, P and K values as evaluated against artificial fertilisers. However, the real value is realised as the benefits of the steadily released, biological nitrogen, compared to the quickly available ammonia and nitrate.

Composted manure is pre-digested by friendly bacteria. The pathogens are eliminated, toxins removed and weed seeds consumed. Manure, in short, is not manure any more – not once it has been digested by this volunteer microbial workforce. Compost offers a natural humus. You could think of it as a fishing net, in which an abundance of healthy, bio-available nutrients are captured, held in suspension, on offer to the soil and plant.

The potential for bio-nutrient use on our dairy farms is hugely significant in the modern light of progression. Fuel needs to be saved, the environment needs to be protected, and above all, healthy productive livestock keep the whole business profitable and enable a better product to be supplied to the human food chain.

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