We have been looking at your soil test and what those numbers mean to your farm. We took a break and looked at how to take a good soil sample. Let’s look at taking a good manure sample.
It’s important to test your manure in order to know the nutrient value that it will provide to your crop. Manure is a valuable resource for providing nutrients, micronutrients and organic matter.
About 75% of what animals eat for nutrients comes out the other end. When you harvest a field, it removes nutrients from the soil. Applying manure on the field will help to recycle the nutrients back to the crop.
Manure value varies from farm to farm therefore an “average” manure value will not be accurate. The nutrient levels can vary depending on the type and age of the animal, bedding material, water runoff into the manure storage and type of manure (solid, semi-solid or liquid).
Manure should be tested every year. We’ve not only seen decreasing soil nutrient levels over the past 6-8 years, we’ve also seen the nutrient value in the manure decreasing as well. Less nutrients in the crop means less nutrients being eliminated in the manure.
Listing animals with the highest to the lowest nutrient value would generally be: chicken, mink, hog, dairy, sheep, beef and horses. For example, it would take 50 tonnes of solid beef manure to equal 10 tonnes of chicken manure. Not all manure is equal!
When deciding on a manure storage facility, it is not only important to retain the solid portion of the manure, the liquid portion is also rich in nutrients. For example, 90% of the phosphorus is found in the solid portion and 75% of the potassium is found in the liquid portion. Potassium can be expensive in a fertilizer mix so don’t lose the potassium in your manure!
WHEN IS THE BEST TIME TO SAMPLE YOUR MANURE?
The most accurate time to sample is right before you spread, when the manure has been thoroughly mixed. The downside is that the results can’t always be obtained in time to adjust the fertilizer mix and rate.
Typically, a sample is taken in the fall or early spring so that there is adequate time to develop a fertility program. This means taking the sample directly from the storage facility. Ensure that good safety practices are followed when taking samples especially when taking a liquid or semi-solid sample from a pit.
Sampling is similar to taking a soil test. Take a number of subsamples from different locations around the manure storage, mix together and take a 1-litre sample for the laboratory.
LAGOON OR PIT (liquid or semi-solid): use caution when sampling from these types of storages. Use a dipper that can be made from attaching a can on the end of a long stick. Take the subsamples after the pit has been agitated to mix the solids with the liquids. Take about 10 subsamples 3-4 feet below the surface. Do not take the subsample from the corners or the crusty surface layer as this may give an incorrect high nutrient reading. Stir the subsamples together to make sure the solids are well mixed and take a 1-litre sample.
PACK, PILE OR BROILER HOUSE (solid): take subsamples throughout the barn using a shovel to collect subsamples and mix to obtain a1liter sample. Collect subsamples near water and feed areas, buildings, fences and the center of the lot where animals spend most of their time. Take subsamples at various depths throughout the pile.
HOW SHOULD THE SAMPLE BE SHIPPED TO THE LABORATORY?
The manure sample should be sent to the laboratory as soon as it is taken to avoid loss of nitrogen gas. If you are unable to take it to the lab that day, freeze it until you are able to send to the lab. Do not use a glass container as it can break during freezing or transport. Plastic ice cream containers or freezer bags work very well. Duct tape the lid and label with your farm name and the type of manure.
Some mistakes that can occur when sampling manure are:
• Taking the sample from behind the animal. This is too fresh and will give false high nitrogen reading.
• Taking a sample and leaving it in the farm building or truck for a few days. As the manure heats up, the nitrogen gas escapes therefore the test will show a false low reading.
• Samples were combined from several different manure storages. They need to be separate as they can be quite varied in their nutrient levels.
• The manure pit was emptied and whatever is left in the corners is scraped together for a sample. This will provide an inaccurate analysis.
Remember that the manure analysis report is only as good as how accurate your sampling method was!
Next article we’ll finish discussing the numbers on your soil test report.
(Any questions on this article or other fertility issue? Contact Lise LeBlanc at (902) 792-2636 or lise.leblanc@ns.sympatico.ca.)
