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Author Topic: TOP SOIL-Is brown or black best?  (Read 8158 times)

newstart

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TOP SOIL-Is brown or black best?
« on: September 16, 2010, 01:18:11 PM »
I am told by the BS3882:2007 british standard for topsoil testers that this sandy loam is best. They sent a sample by post and it is brown when wet. I currently have black soil in my garden however which shows by a water test (test tube test) to have higher levels of organic matter. The sandy loam most sellers sell(brown) is therefore a lighter structure and my tests show lower organic matter present. My current garden soil is still as light to handle and black though. The way I see it is the black holds more nutrients and is better. Why are the above BS standards like they are and is black soil in fact no better regardless of organic matter levels. I intended before all this happened using a black top soil mixture which I can get my region from TBD morris - I can get brown or black from them. I was going to use black for potting and the garden. Potting would have the sand,grit added making a john innes mix as previously discussed but this is a top soil question as well. So its not in the compost forum for that reason.

It seems i am having to throw away at least half of my college education at this rate if the BS brown is better above.

Thanks again I am looking forward to your answers.

Thanks David.
David in Central England. Lots more still to learn!

Maggi Young

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Re: TOP SOIL-Is brown or black best?
« Reply #1 on: September 16, 2010, 03:31:52 PM »
 I had never given a thought as to which colour was "better" because I would think that one would be limitied mostly to the  prevalent soil type in your area.  :-X
Looking into the BS3882:2007 standard I see there is no mention of colour, only of standard and suitability. (se more about this below....)

When buying topsoil, there can be a notion that is the darker, the better.  Darkness in soils is often associated with an high proportion of organic matter but soils which are very dark and grayish may have been dredged from wetland areas.  These soils can be very acidic and poorly structured and  may not perform well in use. 
Nevertheless, as a rile of thumb, quality soil is a rich dark brown or black colour. Of course, the colour can be affected  by the degree of dryness of the product...... wet soil is always darker!!
I would think the likely call for the best soil  would be "loamy," meaning it's made up nearly equal parts of clay, sand and silt.

To  agreat extent the colour of soil is governed by prevailing local conditions..... our soil in our garden is a light sandy loam, it's good stuff and grows good plants, but some types of plants ofr crops will still need additivies  and feeding to make the most of their potential.
Not so very far away from me here in Aberdeen the natural soil is a wonderfully bright terracotta clay colour... and it is rich in clay and sand and is extremely fertile though it looks quite different to anything you would ever buy .... looks aren't everything... it is content, drainage qualities, nutrient values and so on that are important. The BS rating lays out these areas.... but the real test is : does this soil grow  good plants? If not, no matter what colour it is or how many labels someone has stuck on it or given it fancy names, it's duff!
One would hope that soil given a BS3882:2007  rating  would be of good quality. It is up to the buyer to decide what grade of soil he  requires according to the use for which is intended - you'd need to study the recommendations to see what you needed for any particular project.
 
The RHS advice on topsoil says  " Topsoil is generally available to buy in three different grades: premium, general-purpose grade and economy grade.
http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=375    to see more .

The five types of soil available from a supplier like Rolawn  are Blended Loam ;
Vegetable and Fruit Topsoil; Beds and Borders Topsoil; Soil Improver; Organic Multi-Purpose Compost - which sound to me like a good way to make more sales!

This link is to a document that gives quite a lot of details about analysis of various topsoils :
http://www.envirolinknorthwest.co.uk/Envirolink/events0.nsf/0/8025739B003AADE3802574C80041DCCE/$file/080310%20Tim%20Evans%20-%20Soil%20Quality%20Assurance%20%20-%20BS3882%20-%202007.pdf
 
Margaret Young in Aberdeen, North East Scotland Zone 7 -ish!

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newstart

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Re: TOP SOIL-Is brown or black best?
« Reply #2 on: September 16, 2010, 06:44:18 PM »
Thanks Maggie thats an excellent answer ,one worth saving for future people who may ask.

My local soil is black but and more loam and light than clay. Its a true loam rather than a sandy loam but I ought to make sure its not acidic if thats what you say. I could buy a PH kit or a metal prong push in monitor to test it.

Thanks for your time I hope things are going well for you. I finally shifted my bark which was a huge pile of about 70 barrow loads. It will make good compost or mulch.

Thanks again!
David in Central England. Lots more still to learn!

iann

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Re: TOP SOIL-Is brown or black best?
« Reply #3 on: September 16, 2010, 10:13:49 PM »
I wouldn't worry too much about the colour.  Darker colours tend to indicate more organic matter.  Often this would be desirable, but less so for many alpines.  Sandy soils may contain less organic matter and will obviously have more larger grains which tend to be a paler colour.  Beyond that, it is hard to read much into the colour.  Some soils are brown and even red because of their chemical makeup and it doesn't make them bad.  Some soils even have a blue tinge, although these are usually heavy clays which you wouldn't want.

My advice is to get the texture right and forget the colour.  If you're still trying to perfect things after selecting a nice sandy loam, look at pH.  I've seen topsoil sold with pH right across the range from significantly acid to very alkaline, and there are certainly plants that wouldn't be happy with one extreme or the other.
near Manchester,  NW England, UK

newstart

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Re: TOP SOIL-Is brown or black best?
« Reply #4 on: September 17, 2010, 10:52:17 AM »
I must admit Iann that my plants grow like a bomb in the black organic rich stuff. This is what lead me to ask the question and suspect sandy loam as not as fertile. I think this assumption is now less true given other soil structures still hold the nutrients in the crumbs with less organic matter quite reasonably. I will have to watch out for some plants though as they may require a poorer soil. I have a Scutelaria(hope thats the correct spelling) which is not growing very fast at all. I think thats more likely a lack of drainage which requires grit. Planting with grit may well be the answer (as most people do) and it would allow more nutrients to drain out of the soil helping some which did not require the extra nutrients too I'd of thought. My soil holds water better due to high humus hence grit should really be used on all planting probably.

Thanks for your valuable help.

David.
David in Central England. Lots more still to learn!

 


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