Stop hauling your bedding sand to your fields!
If you own and/or manage a dairy farm, then most likely one of your most visited apps or websites is related to the weather. Weather has such an impact on nearly every aspect of farming and dairying. If it’s too hot, the cows and the crops begin to suffer. When the temperatures begin to drop below freezing, there’s always the danger of pipes freezing, access roads becoming slippery and tractors not starting. Crops need water, but when the rain becomes excessive, crops get drowned out and the fields become impassable. This can really cause headaches for dairy producers who manage their manure by hauling it daily, or even weekly, to the fields. Hauling heavy, sand-laden manure to your wet fields can cause rutting and excessive compaction. Oftentimes, the more stable fields can get inundated with manure, which increases the risk of runoff.
If you’re milking a small herd of dairy cows and bedding on sand, you may have struggled trying to haul your sand-laden manure to the fields due to weather issues. The SMS12 system can help you save money on bedding by allowing you to recycle your sand while at the same time making it easier to land apply the remaining manure effluent.
What is an SMS12?
The SMS12 is a sand separation system designed to give dairies with 500 cows or less the same benefits of a traditional sand-manure separation system at a fraction of the footprint and cost. This system utilizes the proven sand-manure separation equipment that McLanahan puts in all of our systems, based on our mining-duty designs. It has an attractive ROI, is quick and easy to install, requires a small footprint, and has low operation and maintenance costs. This system has high recovery rates of clean sand and produces a slurry effluent that can be used in biogas plants and nutrient separation systems, allowing farms to be more environmentally sustainable.
How can this benefit my dairy?
Let’s look at a few of the most obvious ways that separating sand from manure can help your dairy.
1. Cost savings with recycling your bedding sand.
This is usually the biggest and most obvious beneft. To illustrate a typical cost savings, let’s look at the current annual cost of bedding. If you have a 500-cow dairy, use 50 pounds of sand per cow per day and pay $12 per ton for the new sand, your annual bedding cost for the sand will be $54,750 per year. If you don’t already know how much you spend on sand bedding and want to calculate the annual sand cost for your dairy, simply multiply the number of stalls being bedded by 50 (pounds of sand per cow per day), divide that number by 2,000 (pounds per ton), multiply that number by the cost paid per ton, and multiply that number by 365. This will give your annual sand cost, assuming you use 50 pounds of sand per cow per day.
The equation for the 500-cow dairy above would look like this: 500 x 50 / 2,000 x $12 / 365 = $54,750.
The SMS12 system has shown to recover more than 90% of bedding sand from manure. Using the above example, this would return $49,275 in recovered and reusable sand.
You may be thinking, “What about operation and maintenance costs? That’s a good question. If we throw in some expenses based on average electricity costs of $0.07/kWhr and usage, along with annual maintenance, you’ll be seeing a savings of approximately $40,000 per year.
2. Reduced compaction in your fields.
While it’s hard to dispute that hauling sand-laden manure onto crop fields can create compaction issues that negatively affect crop yields, have you ever looked at the difference removing the sand prior to hauling the manure can make on potential compaction? For example, let’s take a typical box spreader loaded with sand-laden manure. This manure will have density of about 72 pounds per cubic foot. A medium sized box spreader can hold about 10 cubic yards or 270 cubic feet. If loaded with sand-laden manure, this will be 19,440 pounds of manure. If we remove all the sand from this manure, the same spreader will weigh 16,740 pounds — 1.4 tons lighter. This is about 14% less weight being taken to the fields.
3. Reduced hauling and cleanout costs.
Removing the sand from manure can reduce the amount of manure being hauled to the fields. Using our 500 cow example from previously, removing 90% of the sand will remove 14 tons of sand per day. A dump truck will usually haul between 20-25 tons of material. Removing 90% of your sand will potentially decrease the manure volume by 200-250 truckloads annually. Some of this volume will be offset by a small amount of additional water that is needed for washing/rinsing the sand, but this volume difference is easier to store/agitate/pump/handle now that there is little sand. The fine sand usually can be agitated, put back into suspension and pumped rather than needing to be dug out with a loader.
4. Minimized wear and tear on equipment.
Hauling and spreading sand-laden manure can be costly. The abrasiveness of the sand along with its tendency to settle out in tankers can be costly and time-consuming to manage. Removing the sand with the McLanahan SMS12 sand separation system means you are managing the sand with equipment built to mining-duty standards and designed for harsh working environments. Pumping and hauling your sand-free manure will put less stress on you and your equipment.
5. Increased cow comfort.
If you’re recycling and reusing your sand bedding, your bedding costs will be minimal. This means you can keep your stalls full and properly maintained without the worry of high bedding costs. Your cows will thank you by producing more milk.
How does the SMS12 work?
The SMS12 uses several of the basic principles of sand separation to separate sand in an economical way within a small footprint. Undiluted manure is pumped into a conditioning box, where closed-loop recycled water is added. The resulting slurry flows into the Rotary Drum Separator for fiber and debris removal. The remaining water and sand flow into the sump and are pumped to the Hydrocyclone. The Hydrocyclone separates the sand and drops it into the sand washer for cleaning and rinsing. Sand is discharged from the sand washer at about 20% moisture content. The sand will need to be stacked and conditioned for several weeks prior to reuse. An optional Dewatering Screen can be added to reduce the moisture to about 12% and minimize the amount of conditioning time required.
The SMS12 system operates on about 35-40 hp and can be configured for single or three-phase electricity. The system can be installed outdoors if the temperature remains above freezing; otherwise, it will need to be installed in a building with minimal heat. Operation is simple and controls can be monitored remotely, with text and email alerts sent when a fault occurs.
If these challenges sound familiar and you’re considering sand separation for all or some of the benefits listed above, read more about the SMS12 system or check out this video and case study from Cornell University. You can also contact McLanahan's Ag Team.