To manure or not to manure

[KG Steve]

Hi All
The next topic for debate in our Over The Garden Fence feature in KG (Feb issue) will be whether manure is essential/desirable for growing crops and we wondered what your thoughts are? Also whether the recent weedkiller contamination problem has put you off and made you look for alternatives? Manure is not always easy to come by depending on where you live and if that applies to you, what do you use instead?
Any comments gratefully received!
All the best CC

[FredFromOssett]

Personally, I have never used manure on the plot for a variety of reasons; it is not easy to come by other than from sources of unknown provenance, or collect your own from local stables – which is difficult without a trailer; the access to the plot is such that any deliveries would have to be dumped outside the allotment gates, adjacent to a block of lock-up garages, necessitating barrowing on to site come rain or shine to restore access.
I am also very wary of weedkiller contamination since the last time I used a bale of straw to mulch strawberries. I had the poorest crop with stunted growth, which I can only attribute to contamination from the straw. Since then I have viewed ‘imported’ materials with great suspicion.
All I use on the plot is the contents of my compost bins, plus an application of chicken pellets (when I remember) a couple of weeks before planting. Additionally, my Brassica bed has had a dressing of ammonia in the spring for the past couple of years, which, incidentally, has greatly improved the quality of these crops.

[Monika]

We use about a tractor trailer load of cow manure every year which is delivered over the fence from the adjacent field in spring. it then matures over summer. Three years ago we did have a problem with aminopyralid contamination but the farmer assures us this has been sorted out. The bulk of the manure is spread in late autumn on one third of the plot and left to lie over the winter before being forked in during early spring. Some we use for mulching the rhubarb and our few fruit bushes, some for the marrow and courgette plants and some is use to "thatch" one of our two large compost heaps.

The addition of this manure (as well as our own garden compost and use of green manure) has made a tremendous difference to the structure of our soil. The very few areas where we have never spread any manure are heavy, almost clayey soil, whereas the manured areas are humus-rich and dark.

[Parsons Jack]

We seem to be lucky on our site. We have a free trailer load of horse manure delivered every few weeks, and there has never been any problem with it
Also there are a few owners with a small amount of horses close by, that fill up bags with manure on a take it away and bring the bag back basis. There is also another stables that piles it up outside for you to help yourself
I have a number of manure bays on my plots, and let it rot down for a year before using.
I also have three 'dalek' bins for composting.
They don't call me 'dung beetle' for nothing you know

[peter]

Essential as its the only widely available bulk source available to the ordinary gardener.
I have collected from a local source of bags by the road free via a friend living next door to the source, he gets the bags before they go to passers by as the sources wheelbarrow squeals loudly.
Sadly last year their paddock was suddenly free of weeds and the subsequent manure killed my friends potatoes and rhubarb, now it seems to be stunting my raspberries.
I would REALLY appreciate a sound scientific article in KG about aminopyralid and its persistance, especially since GLAllotments comment about the three years being the half-life of the active ingredient.
Meaming that 100g in a load of manure placed to rot will after three years have still 50g still active.

[Westi]

Aminopyralid contamination has been off the radar for a bit but with
personal experiences allotment holders are still having and the statistics GLAllotments presented it is not gone at all.

Personally I love the whole ethics of using well rotted manure which was such a natural cycle but I am not willing to risk my crops which attract enough natural predators without introducing something totally avoidable.

I hope GLAllotments continues to keep us up to date on this subject and also want to thank her for all the information to date.

Westi

[glallotments]

I hope GLAllotments continues to keep us up to date on this subject and also want to thank her for all the information to date.

Westi

I certainly will Westi - there have still been problems this year. Not as many reported but it is still there and my web pages that focus on the issue are very well visited.

We haven't used manure since we had the aminopyralid problem and really can't see that we will use it again in the near future. When I was looking into issues around manure I found other things that would continue to make me wary even if I could be sure that the manure wasn't contaminated with weedkiller. For example the realisation that there is potential for different contaminants to be passed on through manure even from organic sources and the fact that following up the provenance of manures is virtually impossible. This means we can't make an informed choice as to what we put on our land.

As for manure being natural well that is debatable - yes it comes from a natural source i.e a cow or horse but it isn't always as a result of purely natural substances going into the animal!

We use fish, blood and bone meal to add nutrients and our own compost, used grow- bag compost and used potting composts etc. to improve structure.

[solway cropper]

I could use manure if I so desired as I live in a very rural area and there's an abundance of the stuff. I know local farmers who would be happy to dump a trailer load on my drive but I make large amounts of my own compost so there's no real need. I also live near the sea and can collect as much seaweed as I need.

With the lawns, a privet hedge and assorted trees and shrubs I can generate enough waste to keep two daleks and a large open heap constantly supplied. Add the seaweed and whatever else can be composted and I have no need for manure.

I do use BFB and pelleted chicken manure in addition to my own liquid feeds so perhaps manure isn't as essential as some people think.

[Monika]

Peter, I understood (probably from the links which Glallotments provided when aminopyralid first reared its ugly head) that the chemical would not leach out or dissipate into the air if the manure was just stacked up but it had to be incorporated into the soil so that micro-organisms could get to work on it. We did that at the time and had no problem the following year. We also avoided growing potatoes on that manured patch because they seem to be particularly sensitive to it. We grew our peas and beans on it and had a good and healthy crop.

[peter]

Monika, the active ingredient is bound chemically to the cellulose making up the cell walls of the undigested portion of the hay made from sprayed meadows, or the grass grazed by the beast.
It is re-released when the cellulose decays. That happens slower in a heap than when rotovated into a plot and thus nicely mixed up with "living' soil, full of microbes, fungi, worms, etc. So I reckon you're both right and wrong, as in a heap it will come out, eventually.

This is why it would be so good if kg could get a proper scientific article written, even give the manufacturer's a chance to put their point of view.

I reckon it could attract lawyers though.

[Monika]

Thanks, Peter, for that and, yes, I would love to read a proper scientific explanation in KG, albeit couched in laymen's terms!

[glallotments]

From what I was told by the stewardship consultant that DOW commissioned, if the manure was stacked and didn't come into contact with soil-micro-organisms then the contamination would be present indefinitely. This is why even if the chemical was no longer used the problem could continue due to stacked manure being already contaminated.

The manure needs to be in direct contact with the soil for the plant cellulose to break -down and the chemical to be released. It's the micro-organisms in the soil that are at work - I guess if soil was mixed into the manure pile it would have an effect albeit slower.

Aminopyralid isn't water soluble - so I was told - shouldn't be present in leachate, however this does not mean that it cannot spread sideways. If rain washes the manure containing aminopyralid away - for instance down a slope or even down the slope of a pile of manure it will spread the contamination as it has spread the manure containing ap not washed the chemical from the manure. (sorry if that is confusing)

As for Monika's experience the length of time it takes for your soil to be free of contamination is variable.

It depends on the concentration of chemical present (if a field has been spot weeded then the concentration will be lower and more patchy than if an entire field has been sprayed - also a pile of manure may contain ingredients from different sources).

Weather conditions also play a part (in dry condition such as inside a greenhouse where the soil isn't watered the breakdown will take much longer as it would be in cold conditions).

Actions by the gardener also have an effect(if soil is frequently dug over air is incorporated and decomposition increases).

If plants that are more resistant to the chemical are grown on contaminated ground and show no signs of damage and are composted then these plants may contain contamination that is then present in any compost being spread.

Some people have suffered the effects of using contaminated manure several years after application and others have been free of the problem the year after. You can't really draw too much from individual experiences.

[Ricard with an H]

OMG. Aminopyralid

Is this something I need to be concerned about, I just started using well-rotted cow poo thats been steeped in water since last year but I have also dug some into one of my raised beds. Thats the raised bed that my bean plants keep going crinkly in.

[Geoff]

Could be that, beans are one of the indicator crops. You could ask the farmer if he has sprayed his pasture or cutting grass (you should be able to find the product names on glallotment links) or bought in hay/haylage that could have been treated.
Alternatively have you used any weed and feed on any of your grass that could have got to this area?

[Ricard with an H]

What do you mean by indicator crop ? I haven't used weed and feed though the barley that produced the stuff the cows used to eat in the winter doubtless was treated with a herbicide of some sort.

The small amount of crop that is grown around here is regularly sprayed but I might not be able to find out whats going on. What do I ask ? Just mention the name Aminopyralid presumably.

Let me get up to speed on that Aminopyralid, google eh, what would we do without google.