Too small a spreader and you’re on the tractor all week. Too big and your tractor can’t pull it, or you’re tearing up wet fields. Here’s how to work out manure spreader size properly.
Step 1: How much manure?
Estimate how much solid manure you need to move per week or per clean-out. Your animal numbers, bedding use and housing type decide it. Extension services publish typical figures by animal type. Better still, count loads you’re moving now.
Step 2: How often do you spread?
Daily spreading needs a smaller machine. Spreading a few times a year, after pen clean-outs, needs more capacity or more trips.
Also think about spreading windows. Rules and weather may limit when you can spread. Bigger capacity helps you use short windows.
Step 3: Haul distance
Long trips to fields mean fewer loads per hour. A bigger spreader cuts trips. Short haul, a smaller spreader cycling quickly can keep up.
Step 4: Tractor power and weight
A full spreader is heavy. Check:
- Recommended tractor horsepower.
- Hitch and drawbar ratings.
- Braking for the road and slopes.
Step 5: Fields and soil
Big spreaders mean heavy axle loads. On wet or soft soils, that means compaction. Wider tyres, tandem axles or smaller loads can help.
Step 6: Loader
Your loader needs to reach over the side of the spreader comfortably. Check heights.
Simple maths
Volume per week divided by spreader capacity equals loads per week. Multiply loads by time per load (load, travel, spread, return). That’s your hours. If it’s too many, go bigger or get a faster loader.
Start with your manure volume
Work out how much manure you produce in a season. Your nutrient plan, pen clean-out records or extension guides can give a starting point. Divide by how many spreading days you realistically have. That gives the daily amount you need to move.
Load size and trips
Divide the daily amount by the spreader’s working load. That’s the number of loads. Now think about how far it is to the field and how long each trip takes. If the number of trips doesn’t fit your spreading window, you need a bigger spreader, a second one, or a contractor.
Tractor match
A bigger spreader needs a tractor that can pull, brake and power it safely when loaded. Check the recommended power and check your hitch and brakes. Hills and wet ground make it harder.
Loader match
A spreader that takes many loader buckets to fill wastes time. Match the spreader to your loader bucket size so loading is quick.
Soil and compaction
A bigger, heavier spreader can compact soil more. Wider tyres, lower pressure and timing help. Sometimes a mid-size spreader making more trips on dry ground is better for the soil than a big one on wet ground.
Growing herds
Plan for where you’ll be in a few years. Buying slightly bigger can save buying again soon.
Don’t oversize
An oversized spreader costs more, needs a bigger tractor and may be awkward in yards and gates. Size for your real needs.
Quick questions
Is bigger always faster? Not if the tractor or loader can’t keep up.
What about contractors? A contractor with a big rig can cover peak loads while you own a smaller spreader.
Should I size for wet or dry manure? Wet manure is heavier. Check weight limits as well as volume.
From the show floor
I ask spreader buyers one thing: how many days do you really get in spring? The answer usually decides the size.
Where to start this week
Count last year’s spreading days and the loads you hauled. Divide one by the other. If you were rushing every day of the window, you’re undersized or short on help. If the spreader sat most of the season, you may be oversized. Either answer helps the next decision.
Quick questions
How do I estimate my manure volume? Use extension guides for your animal numbers, then check against real loads hauled.
Is a second spreader worth it? On busy farms with short windows, often yes.
Should I size for the road or the field? Both. Check weight rules for roads and soil conditions in fields.
What about tight yards? A slightly smaller spreader that fits easily may be faster overall.
Rear or side
Choose the type for your manure, then size. See rear discharge and side discharge options.
Bottom line? Size for your manure, your windows and your tractor. In that order.
