Keeping the soil in good heart

Soil, the productivity heartbeat of any farm, was the topic at the recent meeting of the Quality Meat Scotland (QMS) Kintyre Monitor Farm, Glenbarr Farms, situated on the west coast, just north of Campbeltown. 

Owned and farmed by Duncan Macalister, Glenbarr Farms extends to 1,730 acres (700 has), with land ranging from hill to shore-line. Mr Macalister runs a suckler of herd of 140 cows and a breeding flock of 550 ewes. Barley acreage totals just over 100 (40 plus has). 

In his welcoming address at the initial monitor farm meeting, (March 2011), Mr Macalister had included “breaking up the soil pan and lifting the pH” on the list of challenges for the community group during his monitor farm term. He had added – “this used to be a dry farm, but over the recent ten to fifteen years, it’s become wet, which can’t all be blamed on higher rainfall!” 

At the recent meeting, Lancashire-based James Bretherton, a cattle nutritionist and soil specialist, outlined some of the straightforward ways of assessing soil and enhancing its productivity. 

“To get the most from your soil, you must understand it”, he explained. “It’s important to appreciate that your farm’s soil is a living environment. Livestock farmers know that to maximise production and efficiency from their livestock, the stock need to be healthy. It’s the same with soil; for good grass and crops, the soil must be healthy and well structured”. 

Mr Bretherton outlined the make up of a good soil as being 45% Mineral, 25% Water, 25% Air and 5% Organic Matter, with a target pH Value of between 5.9 and 6.5. 

MINERAL

Dependant on soil type, the main minerals, in Base saturated percentages, are Calcium (60 -70%) and Magnesium (10 – 20%).

AIR

Air was described by Mr Bretherton as crucial – “Anaerobic (absence of oxygen) soils result in poor palatability of grass, restricted Nitrogen cycle and uptake of soil’s natural Phosphate. Mineral uptake is also restricted, which can have a negative effect on livestock fertility and health”. 

Anaerobic soils often have poor drainage, creating colder soils than aerobic soils, resulting in slower grass and plant growth. “With grass growing at six degrees Centigrade, it’s worth ensuring well drained soils make the most of early growth opportunities.” 

Mr Bretherton used a soil temperature gauge at the meeting, which took place on 13th January. It showed that in the same field, well drained soil was above 6 degrees, while wetter land was 2 degrees colder. 

Causes of anaerobic soils include heavy slurry applications as slurry sucks the air out of the soil, or shallow surface panning (usually in the top three inches) by livestock. 

Mr Bretherton recommended that slurry applications be made, if possible, “little and often”. 

With regard to Farmyard Manure (FYM); leave it to rot down for a year (the composting process also helps to kill MAP, the bacterium which causes Johne’s). The rotted FYM is more speedily digested by the microbes in the soil. 

With purchased fertiliser prices more likely to rise than fall, Mr Bretherton recommended establishing the N, (Nitrogen) P, (Phosphorus) and K (Potassium) values in slurry and FYM, to help control fertiliser costs. 

If livestock have compacted the top three inches, aeration with a sward slitter (not on light soils) in spring and autumn can break up the compaction, allowing air into the soil. 

When re-seeding, the incorporation of deep rooted plants, such as chicory, red clover, lucerne, fodder/sugar beet into the mix, will help to break through a deeper soil pan, while releasing locked up nutrients from below. 

James Bretherton has, at Mr Macalister’s request, undertaken a full soil analysis, which will establish the level of locked up Potash and Phosphate in the soil, which Mr Macalister intends to “un-lock” and use. 

ORGANIC MATTER

Mr Bretherton told the group that organic matter is vital for good soil as it provides a food source for soil life, fertility and structure. It also facilitates the exchange of nutrients to plants and prevents the locking up of natural Phosphate within the soil. 

Organic matter also helps to incorporate air into the soil, with mites, insects and significantly worms, living off the fungi within the organic matter. “Worms move a lot of soil, creating drainage, which in turn helps to make warmer soils, plus their excrement is an excellent soil nutrient.” 

Mr Bretherton explained that the worm population can indicate the level of organic matter in soil and ideally there should be between six to ten worms per cubic foot of soil. Minimal or non-tilled soils generally yield higher worm counts. 

Regular basic soil sampling gives pH, Phosphate, Potash and Magnesium levels. Mr Bretherton explained that high Magnesium combined with low Calcium levels will cause “tight”, anaerobic soils, thanks to the Magnesium bringing soil together, whereas Calcium opens it up. 

“It’s important to keep the soil balance right and stock farmers should not go away from maintaining Magnesium levels through lime application”, warned Mr Bretherton. “Magnesium helps to prevent Grass Staggers (Hypomagnesaemia). 

“If you feel that a field is not “working”, a quick and easy soil Condition Score can be done by spade digging a hole. Assess the tightness of the soil by the way the spade moves through it, look at the root mass, count the worms and smell the soil”. 

• A tight soil suggests lack of air. 
• Shallow roots indicate a pan or tight soil.
• Lots of worms are a good indicator while few or no worms are bad.
• A sour or no, soil smell is also bad.

“Soil doesn’t actually smell”, explained Mr Bretherton, “the smell is created by the soil bacteria, and a good smell is a good indicator of soil life”. 

If the field has been cultivated, Mr Bretherton recommended digging near the centre of the field and again at the un-cultivated headland, and comparing the soils. Comparisons can also be made with soils from neighbouring fields. 

He advised the group to avoid ploughing whenever possible. “Ploughing weakens the soil’s strength. But, if you must plough, avoid ploughing deeply, because this will bury and kill the organic matter, which is vital to the soil’s structure and fertility.” 

At the close of the meeting, Mr Macalister said “Having heard what we have today, we realise that previous generations, who used deeper rooted plants and less time, machinery and expense tilling the soil, were making the most of their soil, while keeping it in good heart. So what we really need to ask ourselves is “Why do we plough?” when it’s obvious that less or no ploughing is far better for the land and its production.” 

The next meeting of the Kintyre Monitor Farm will be held at the end of February/early March. 

For further information, please contact either of the joint Facilitators:-

Alan Boulton, Telephone: 01397 708891.

Email: alan@huntawayconsulting.co.uk or

Linda McLean, Telephone: 01586 820226

Email: kilmahofarm@btconnect.com

For general information on Monitor Farms, plus detailed reports of meetings: www.qmscotland.co.uk/monitorfarms

Caption: Monitor Farmer, Duncan Macalister, smelling the soil from his stubble ground