Autumn Questions

It's been a dreadful growing season this year here in the North East, and the last few months have given us a miserable August, a very soggy September, and October frosty cold but there has been some brilliant sunshine. Perhaps this was the 'Indian Summer' that was forecast, but with these frosts it doesn't feel like India! This time last year I was sweating in the humid sub-tropical climate of Uttar Pradesh with daytime temperatures of 30oC.

Here in the UK the nights are drawing in and with the shortening of the days and the early morning frosts, Autumn is once again upon us. I find Autumn quite a spectacular time of year as the trees change in colour before losing their leaves, it's one of the best times to enjoy the colours and go for a walk in the woods. October also brings to an end British Summertime, sending the clocks back one hour and marking the arrival of shorter daylight hours and colder unsettled weather as the cold polar weather starts to affect the North East coasts.

For me it's also a time to clear out this years garden crops and everything from the polytunnel apart from chillies an the late chrysanthemums which will use the tunnel as a temporary home. Outside my target is to get the ground dug over in preparation for next years challenges. Normally I would spread well rotted manure over the recently dug soil to allow the winter weather to work it into the ground this year I'm not so sure.  I know of a few instances this year on the allotment site where I have my plot, of contamination by aminopyralid contaminated manure. Aminopyralid is a component in a number of products designed to target deep-rooted perennial weeds in grassland, including docks, thistles, nettles, and ragwort.

The source of the manure have said that they haven't used aminopyralid, but have withdrawn the manure from sale. There was an issue a few years ago and the products containing this material were withdrawn but apparently it is back on sale again. The following is taken from advice issued by the UK HSE - Quoting the Health and Safety Executive : (http://www.pesticides.gov.uk/safe_use.asp?id=2926 ) "Aminopyralid is an effective herbicide with a low toxicity to mammals. However residues of it can remain in grass from treated land and pass into the manure of grazing livestock, where it remains tightly bound to the plant material until it decomposes. Similarly, the substance can also remain in grass fed as hay or silage to horses and housed cattle, again passing through the animals into the manure.

If manure is applied to soil or crops before the plant material in the manure has fully decomposed, susceptible crops may be damaged.

Labels of products which contain aminopyralid therefore include warnings not to use manure from livestock, which have eaten grass from treated land, on susceptible crops, or on land intended for growing such crops, until all plant material had fully decomposed.

However it would appear that in the past the label precautions in respect of manure may not always have been followed when manure has been supplied to allotment holders and gardeners...........Susceptible crops include peas, beans and other legumes, carrots and parsnips, potatoes and tomatoes,and lettuce and similar crops." - also Dahlias and some roses.

I have been told that land or compost contaminated with this product can retain aminopyralid for six years, although the manufacturers say it should have gone within 1 year! They suggest regular rotovation and digging will help to aerate the soil and accelerate the breaking down of the product.

I generally source my manure from small stables who say the land they use for grazing isn't contaminated and they don't use products containing this chemical. But what of the hay and straw that they buy in, can they be sure it's not come from fields and meadows that have been treated?

In the information provided by the HSE in the reference above they quote........ “So if crop damage has occurred as a result of the use of manure containing aminopyralid, this almost certainly results from the use of aminopyralid prior to suspension in July 2008. This would not indicate that the new restrictions on aminopyralid products are not working.” 

It is unclear to me whether the instances locally are due to failure of the stewardship conditions, or due to the use of old stocks of contaminated, hay or silage or even that the manure has been around for four years??.

I may be overly suspicious but the evidence I've seen this year came from recently sourced manure so it had to come from somewhere, and to believe that it's 'old stock' is stretching it a bit!

I just want to get next years produce underway, giving the best start possible and so my gut feeling is to concentrate on rotted seaweed, chicken pellets and 'Green manures' to add nutrients to the soil this coming year otherwise I risk a disappointing year and an expensive one at that.

To check farmyard manure you've already sourced you can use the 'bean test' :-

Mix together well -1 part manure with 1 part multi-purpose compost in a clean bucket (make enough to fill 3 or four 5” pots).

Fill another four clean pots with only the multi-purpose compost. These are your control comparisons.