How to ensure slurry isn’t damaging soil or forage quality
As a keeper of ruminant livestock, you have a head start when it comes to understanding one of the Next Big Things in farming. This is because you know about rumen microbes. The more healthy and vigorous they are, the better a ruminant can produce milk or nurture a growing fetus. Without them, cattle and sheep would die.
With Next Big Things in mind, a word we’re going to see a lot is ‘microbiome’. Just like the rumen microbiome that we’re familiar with, human and soil versions are starting to be discussed in the media.
Our human microbiome is a life-sustaining population of micro-organisms that each of us carries round in our gut, body cavities and urogential tract. In plants and soil, scientists have established the Earth Microbiome Project, with the bold ambition “to characterize global microbial diversity for the benefit of the planet and mankind”.
Similar to the rumen, just one teaspoon of soil contains up to 50,000 species of micro-organism. Essentially, the healthier the soil microbiome on your farm, the more productive is the soil. And one factor in particular, according to Liz Russell here at Envirosystems, that can have either a beneficial or damaging impact on grassland soil microbes is slurry.
“Too often during storage, fibrous material floats to the surface and forms a crust, through which light and oxygen cannot penetrate,” she explains. “Below this, small particles sink and form a sludge at the bottom, with a liquid portion above it. Anaerobic (zero oxygen) microbial activity creates acidic, septic and foul smelling conditions in both the liquid and sludge layers.
“Clearly, spreading this does contribute to plant nutrients and organic matter, but it also inoculates soil with a high loading of anaerobic microbes, washed into the ground as an acidic soup.”
Ruminant specialist Dave Lievesley says, “it’s deeply frustrating to watch cows turned out onto fresh grass and not see them put their heads down to graze and it’s not as unusual as you may think.
“What’s even more disconcerting is that it’s happening more on farms that take great pride in their grassland management and are used to growing bumper crops of grass.”
On a number of farms, Mr Lievesley credits biological aerobic slurry conditioning and a corresponding reduction in bagged nitrogen fertiliser with transforming pastures from “plenty but unpalatable” into “lush and irresistible” over a five year period.
Liz Russell reports that the biological conditioning treatment Slurrybugs prevents crust formation in slurry stores and helps create uniform consistency from surface to the bottom. “This means minimal stirring is required before spreading, reducing markedly the workload and fuel consumption involved,” she explains.
“Clearly, this reduces costs and helps improve the farm’s carbon footprint. Moreover, natural biological methods like this can achieve healthy aerobic soil conditions rather than expensive machinery, which in the wrong conditions, of course, can do more harm than good. Over the long term, I’m convinced that the value of improving the soil microbiome will dwarf these more immediate gains.”
For advice on treating your slurry, please contact our advisers on 01772 860085.
Green bedding questions and other (better) options for cubicles
From time to time, interest reappears in the use of recycled manure solids (RMS), ‘green bedding’ according to some, and not without controversy. For a balanced view, guidelines were published last December by AHDB Dairy.
Wales – not allowed.
Scotland & England – allowed subject to defined procedures, including 14 legal requirements. Must comply with Red Tractor assurance.
RMS as bedding material continues to be under review and its conditions of use may change.
The stimulus, of course, is recurring interest in reducing costs while matching the strengths and overcoming weaknesses of other materials.
Clearly, sand is popular for cow comfort and being inert and therefore inhospitable to mastitis pathogens, but not all slurry systems can cope with it. Though straw is readily available, prices fluctuate markedly with supply and demand and chopping consumes fuel and staff time. Even when chopped, straw is very low absorbency.
Wood shavings offer better absorbency, but are expensive. As long as sawdust has been screened to remove large splinters and even nails, it offers good comfort and moderate absorbency. Shredded paper has been tried in the past but suffers from high cost and low absorbency.
Here at Envirosystems, a new dried paper pulp with sawdust material has been developed that goes 40% further than the original 100% pulp version. The new material is 95% dry matter and many times higher absorbency than wood shavings or sawdust, chopped straw or sand.
Like blotting paper, it soaks up urine and leaked milk, helping keep udders clean and hygienic. Just like the original, it also stays put on cubicle beds much better than 100% sawdust or shavings.
Users of the new Envirobed Premium Blend report that the same quantity as one month’s supply of original material now lasts at least six weeks. Among them is John Yeoman, with 800 cows at Y Farms near Shepton Mallet, Somerset, where cow comfort and cleanliness are paramount in pursuit of high performance and excellent udder health.
The paper pulp with sawdust material’s blotting paper absorbency, combined with staying where it’s put on cubicle beds, make a significant contribution, Mr Yeoman says, to low mastitis incidence and low somatic cell counts.
Recommended daily use is two to three litres per cubicle, costing 8-12p/day based on bulk pricing, making it one of the most economical cubicle bedding options as well as best performing. Envirobed products are biodegradable and compatible with all types of slurry and manure systems.