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The GREEN HORSE - sustainable horsekeeping

APRIL MAY 2008
Vol 29-6

In the April/May 2008 issue of The Green Horse you will find the following articles:

Information Exchange - Reader’s Tips, Views and Questions
Horse Manure by Neil Clarkson
National Horse Alliance. When Wire Aint Wire
PVC Fencing. Blue Heliotrope by Nicola Field
Deeds, Steeds and Weeds
Growing Equine Herbs - Sweet Cicely by Fiona Adams
Tips for Water Tanks
10 Rules for Keeping Pasture by Chris and Tracey Ferreira

HORSE MANURE
by Neil clarkson

Composting manure is a better option than bagging up manure to sell or give away - compost = less weeds = customer satisfaction!

Once, when many families had their own vegetable gardens and compost heaps, there were plenty of takers for horse manure.

Horses doing their business on suburban streets were rarely a problem, because plenty of householders were prepared to race out with a shovel to collect the bountiful baubles.

Horse manure contains plenty of fibre, making it an excellent soil conditioner. However, it doesn’t rate right at the top of the Pantheon of Poo. That honour belongs to chicken manure - indeed, any bird droppings. Emeritus Professor of Soil Science John Walker says bird droppings are top of the heap for good reason. Horses - indeed all mammals - produce both urine and dung. Mammals secrete most of their nitrogen, potassium and sulphur through their pee, meaning their droppings are almost always deficient in these key elements.

Birds, on the other hand, excrete through one hole only, meaning all these essential exhaust nutrients are rolled into one neat product.

Bad Press For Poo
Horse dung may have its shortcomings, but it has also received some bad press. Sadly, society now moves way too fast for the humble horse poo. The scenario is all too common: A grateful horse owner who is not in a position to use harrows finds a friend to take away a few bags of freshly collected horse droppings. They dig it into their garden, then complain to the horse lover a few months later that it was full of weeds. They rarely come back for more.

Scooping poop: if harrowing isn’t an option, you face the fun job of collecting the dung. The challenge is then to find something useful to do with it. Through all this, nobody appears to have told horses that demand for their nifty nuggets has fallen away. They just keep on producing them at an average of 15 or so dollops a day. This has given rise to what economists call a glut. And, to use business parlance again, there’s nothing worse than an oversupply in a bearish market. Composting Horse dung has been much maligned because people are bypassing the one crucial step that every keen vegetable gardener knows about:

Composting.
Composting is the process whereby naturally occurring microbes break down organic matter. A perfect compost is a soillike material rich in nutrients and full of roughage which, when added to the garden, improves soil structure and plant health. The critical thing is overcoming the weed problem. Yes, seeds do pass intact through a horse’s digestive system and will grow if given the opportunity. No self-respecting weed seed would ignore the opportunity provided by anyone who digs them straight into the soil.

The Heat Solution
The solution is heat. Your consummate composter is aiming to fry those pesky seeds. One of the byproducts of composting is heat, and, if enough is created for long enough, it will kill any seeds and pathogens, providing you with a weed-free compost. Professor Walker says 80 degrees Celsius is considered the mark at which you’ll achieve this. However, he says it is not always easy to achieve, and some trial and error may be required to get your composting on a roll. If your heap develops an unpleasant smell, you should turn it immediately. The unpleasant smell can attract flies that may lay eggs in your heap. The usual cause is overwatering, or perhaps you didn’t pay enough attention to the layering of the material when you built it. The heat generated in turning the heap should be enough to kill any fly larvae. If everything goes well with your heap, you should be creating pathogen-free compost. However, to be safe, you should always wear rubber gloves and a mask to reduce the chances of inhaling anything unpleasant. Better safe than sorry.

Creating The Right Balance
You need to create a heap that’s got the right balance of material, moisture, and any added nutrients to encourage a healthy growth in the number of micro-organisms that will compost it. Crucially, it needs to be big enough for the heat produced by this process to get to critical temperature, and stay there for two, even three weeks. You’ve also got to allow air to get to the heart so your composting will occur with air (aerobically) and not without air (anaerobically). Let’s assume you’re not really wanting to invest in building or buying compost bins, nor be too scientific about how much fertiliser to add. After all, we’re making compost, not baking a cake! Pick an area well away from anywhere where odour might be a problem. No neighbour wants a compost heap under their kitchen window. Having said that, a wellbuilt heap should not generate an unpleasant smell.

Building Your Heap
You’re going to build a heap with a base about 2 metres across. Don’t put any covering on the ground, as worms and microbes will be prevented from entering your heap from the earth. Ideally, you need room beside it for a second, third, even fourth heap, for reasons we’ll explain later. If you’ve got some old netting around, form 2 metre rings with that to contain your heap. You’ll get a better-shaped pile that way, with a bigger heart, which is where the greatest heat will accumulate. Start shoveling in your horse manure. You’re aiming for a final height of over a metre. You need not build it all at once, but remember that the high temperatures you need won’t be achieved until your pile has a decent heart. Build an even layer of about 15 centimetres. If it’s dry, get your hose and spray water on until the dung is damp, but not soaking wet. If it’s too dry, the composting process will be slowed and the big heat build-up you need just won’t happen.

The Importance of Fertiliser
A sprinkling of fertiliser as you go, preferably one with a high nitrogen content, will help speed up the composting process and improve your end product. Get some general purpose fertiliser, preferably with a healthy level of nitrogen, and sprinkle a handful over the dung. Eliminate fertiliser at your peril - a shortage of nitrogen is a common cause of slow or ineffective composting. Now you need a layer of green matter. Lawn clippings are great, but you can use leaves, hedge clippings, vegetable scraps, old hay and the like. This layer should be a little deeper, as the final heap needs to be at least 50 percent green matter. Then, repeat the layer of horse manure and a sprinkling of fertiliser, paying attention to the moisture content as you go. If you’re tempted not to add any fertiliser, bear in mind that any deficiencies in your soil will show in your plant matter as well as your horse dung, and, ultimately, your compost. It’s a chance to break that cycle.

The heart of your compost heap needs air. A simple way of achieving this is to get a crowbar or a strong stick and make several holes, preferably pushing to the base of the heap - do this three or four times to give your heap sufficient ventilation holes. See if you can push right to the bottom, work it around a little, and withdraw it carefully. If all goes well, the centre of your heap should start composting rapidly.

Look out for the next installment of Manure: an easy guide to composting, in the next issue.