We have been recently asked by Donna on our FacebookPage about manure:
A bit more info would be brilliant...have always wanted to use it but haven't known how to use it to get the best results (we have 5 raised beds in a terraced house garden) I was possibly going to get another compost bin and fill with manure from a friends horse and leave till the end of the year/next year and use it to put nutrients back into the soil after the growing season?
Manure can puzzle many new to gardening, and many who think they know all about it still cling to the common mistake of digging muck into their plots in autumn. The truth about manure is far simpler. There are several types of manure, and rather than seeing as a feed, we need to see it as a soil conditioner:
Horse Manure is wonderful stuff but when fresh, is also the hottest of the manures. We regularly see large mounds of the stuff building up on the farms around Pig Row. There is always one guarantee with horse manure stacked in large quantities, it will at some point over summer spontaneously combust. This means horse manure should be stacked for six months in order to cool but more importantly to eradicate any chance of E.coli 0157. Horse manure is readily available if you live near a livery stable and you'd be surprised how many are in your area, regardless of urban or rural setting. Most livery stables give the stuff away if you're willing to cart it. Horse Manure tends to have a typical nutrient content of 0.6% of nitrogen, 0.6% of phosphorous and 0.4% of potassium. It is recommended, as with all manures, that you find out whether the source is organic certified, including the grazing land or whether the land is contaminated with perennial weeds that will pass through the horses intestines and straight into your soil. This is why it important to stack fresh manure to allow these seeds to be destroyed by the heat.
Sheep Manure is not always available unless you want to go trudging over farm land. If you have sheep though, don't overlook this manure (or goat manure). It makes excellent liquid fertiliser - you'll never collect enough to dig into a bed - because the nutrient value is higher in the nitrogen range than horse manure with 0.8%, 0.4% phosphorous and 0.5 potassium use as a liquid feed by placing it in a hessian sack suspended in a water butt.
Pig Manure. Many small holders keep pigs and many small holders will tell you that last year's pig pen, is this years veg plot. It's hard to collect pig manure beyond that deposited in a shelter on straw. It is best to see pig manure as part of a cycle, reusing the land they have been on for crops in the second year and moving the pigs onto land that needs clearing. Pig muck is wet and cold, not easy to handle fresh and has a typical nutrient value of 0.6% nitrogen, 0.4% phosphorous and 0.6% potassium.
Chicken Manure. Another favourite with gardeners and poultry keepers, easy to collect, easy to store in an active compost heap. The commercial horticultural brigade caught onto chicken manure some years ago, and produce dried pelleted stuff but this is totally a different product to that collected from your own chickens. Dried pellets don't come with eggs and meat. Fresh chicken manure is powerful stuff, mixed with straw bedding or paper shreddings it is power house of a fertiliser. The best way to tackle the stuff is to scrape it out with the bedding and mix into the compost heap, it will turn your cold compost heap to a hot one. If you keep chickens then this is a great way to create a cycle in your garden. The nutrient values speak for themselves as nitrogen comes in at a whopping 1.5% on average, phosphorous at 1.5% and potassium at 0.5%.
Farmyard Manure. This is the manure you will find bagged at most garden centres, it has become a catchall word and tends to be a blend of manures but typically it is cow muck, mixed with other ingredients. It is best to check these blends, as each producer has their own unless you have access to proper cow manure we wouldn't advise using the farmyard manure from garden centres unless it is Soil Association approved (if you are outside the UK, look for agencies and organisations set up to promote Organic growing). It's not as great as horse muck or chicken manure for ready access but the nutritional value of pure cow manure added to the soil is 0.6% nitrogen, 0.6 phosphorous and 0.3 potassium on average and does lead to some great soil conditions. Cow manure rots down to a light, frothy compost, warm to the touch and great on the soil. If you can get it, use cow manure.
All manures have a limited shelf life once incorporated into the soil. As previously mentioned, by digging any of these manures in at the end of autumn you will see the small percentages of nutrient value leach away in the winter rains and snow. It is best to apply well rotted manure to any beds demanding it six weeks before planting or sowing. You will see the difference if you do it every year (this is not like liming your soil, which you do every 3-4 years). We would advise that the best thing to manure your plot with over autumn and winter is green manures. You can under sow your crops in the first or second week of July with red clover, we have done this now for a year and the results have been spectacular, We take our crop and the clover creeps in to the gaps left, locking nitrogen into the soil for next year. Then six weeks before planting, run a mower over the clover and chop the roots up with a sharp spade and lightly turn in.
All plants need nitrogen, phosphorous and potassium. Garden compost can also provide this too but advice given to us during our Wartime Garden experiment was:
But, you may say, farmyard manure is very scarce...So it is a question of using wisely what little manure you can get or the compost you can make. If you manured about one-third of your land with farmyard manure or compost every year and practiced crop rotation, you will go someway to keeping your soil in good heart. The one-third of plot most suitable for this treatment is the part where you are going to grow your onions, leeks, peas and beans. - Allotment & Gardening Guide Vol.1 No.1 January 1945.
There are other feeds associated with certain crops, lime with cabbage, potash with fruit and we sometimes believe that manure is the wonder muck of the plot. Sadly, this is not the case and soil should be responded to for what grows best there. We do recommend a great book by Geoff Hamilton called Gardeners' World Practical Gardening Course. It discusses many of the practical day to day tasks in the garden and is extremely useful to new and old gardeners alike.
If you're not sure what to do with manure...compost it. That's the best advice, stack it for six months to a year in your compost system and then add to the soil. You will avoid weed seeds, Ecoli and more importantly will still have a great soil conditioner. We will be looking at how to make manure tea later in the year.
If you want to use fresh manure then you can go down the hot bed route in early spring. Stack your manure in a 1m (3ft) square. You can contain the sides with old sheet metal or boarding, or even leave it open to the elements. Cover the top of the heap with 23cm (9 inches) of soil, good quality garden compost (home made or bought) and grit (ratio of 6:3:2 - so 6 parts soil, 3 parts garden compost and 2 parts grit; if you are confused about this, think of it in buckets: 6 buckets of soil, 3 buckets of garden compost and 2 buckets of grit, repeat until you get the necessary depth). Sprinkle a light dressing of blood, fish and bone. Place a cold frame on top of the hotbed and sow or plant inside once the bed has warmed up (stick a piece of bamboo cane deep into the bed, if when pulled out the cane is warm to the touch, get growing!). Good crops are strawberries, lettuce, radishes and spinach. Do remember to open the cold frame on hot days or you may be faced with a furnace. Hotbeds are not without risks, they can combust, mainly due to a high straw ratio. In autumn, crack open the now well rotted hotbed and use the manure as mulch next spring.
So, what have we learnt about manure?:
- That the nutrient value of manure is not as high as many think. It is not a wonder feed.
- That we shouldn't dig manure in over autumn because the nitrogen will be washed away.
- It's best to use well rotted manure, six weeks before sowing or planting a bed that requires manure (see 8).
- That manure should be a minimum of six months old and if you don't know, compost it or run the risk of E.coli and weeds.
- If you are unsure what to do with manure, compost it.
- That there are green manures, like red clover, that you can under sow in July which will protect your soil over winter and feed your plants next summer.
- That there are three main nutrient groups for plants: nitrogen, phosphorous and potassium, and we need to get a balance between these three for good, living soil.
- That manure is best used on crops that demand a higher feed, like onions, leeks, beans and peas. For other crops, see blood, fish and bone, lime and other organic feeds, such as, foliage feeds like seaweed.
- That fresh manure can be used in hotbeds and you can get an early crop in spring and still have well rotted manure in autumn.
- That crop rotation helps the soil.