Ohio State University Fact Sheet

Food, Agricultural and Biological Engineering

590 Woody Hayes Dr., Columbus, Ohio 43210

Worksheet 3. Swine Composting Worksheet For Windrows

AEX-713_w3-97

Step l. Calculate windrow volumes.
Primary windrow volume ______________ x 20 =______________ Cu ft
                        Lbs loss/day
Secondary windrow volume = primary windrow volume =______________ Cu ft
Step 2. Specify windrow height and calculate windrow cross section (XS) areas.
Windrow height =______ft (a tall windrow generally makes better use of pad area and sawdust)
              (5 to 7 ft)
Primary windrow XS area (select from table below based on specified windrow height):
                       Windrow height (ft)      Primary windrow XS area (Sq ft)
                              7                                56
                              6                                42
                              5                                30
      Secondary windrow XS area = primary windrow XS area =______________ Sq ft
Step 3. Calculate windrow lengths.
Primary windrow length =______________ Cu ft / ______________ Sq ft =______________ ft 
                        primary windrow        primary windrow       to nearest foot
                            volume                XS area
                            
      If the windrow length is less than twice the windrow height, you do not have enough 
      volume to readily achieve the desired windrow height. Reduce the windrow height and 
      go back to Step 2.
Secondary windrow length = primary windrow length =______________ ft
Step 4. Calculate the required dimensions of the composting pad.
Pad length=______________ ft + 10 feet =______________ ft
           primary windrow
               length
      Standard pad design width provides for both primary and secondary windrows on 
      the pad, a 1 foot top width, 1:1 sideslopes, and 10 feet of open pad to the 
      side of and between windrows.
Windrow and pad widths (select the appropriate values based on the windrow height used).
Windrow height, ft    5    6    7
Windrow width, ft     11   13   15
Pad width, ft         52   56   60
Pad dimensions=______________ ft x ______________ ft
                 pad length           pad width