Ron Fleming and Malcolm MacAlpineUniversity of Guelph Ridgetown Campus,
Ridgetown, ON, N0P 2C0
Paper No. CSBE08-142
BackgroundNMA sets limits on spreading rates based
on:Land slopeHydrologic Soil GroupApplication method (e.g. incorporated)Distance to surface water
Factors influencing runoff risk:Soil textureSoil structureLand slope Soil management Vegetative cover Soil moisture level
Risk of rainfall after spreading
Frost in soil Manure DMRate of application Application method
Objectives• Develop maximum land application rates
for liquid manure.• Assess the impact of post application
rainfall events on runoff on different field slopes
• Propose maximum land application rates on pre-tilled and untilled land surfaces
SetupSmall plots – 1 m x 1 mDifferent land slopesDifferent manure typesSurface-applied manureHSG: C or DSimulated rainfall on some plots
SetupFactors Number DetailsLiquid applied 3 Swine, dairy, waterLand slope 3 3 to 5%, 6 to 8%, > 9% Application rate 3 46.7, 93.5 and 140.2 m3/ha Tillage 2 Un-tilled vs tilledReplications 3Total plots 162
Site 1, un-tilled section, 2.9% slope
Site 1, tilled section, 2.7% slope
Rainfall simulation1 in 5 year storm
(25.5 mm in 30 minutes)
24 hours after manure applied
On 2/3 of plots
Site 2, tilled section, 4.7% slope
ResultsSpreading after wheat harvest in August &
SeptemberSoil: silt loamHSG: mostly CDairy manure: 7.4% DMSwine manure: 2.5% DM
Site 1 - 2.8% slope
Site 2 – 5.0% slope
Site 3 – 15.1% slope
Results (cont.)
Results (cont.)Average volume of runoff was highest at
steepest slope (Site 3) – other 2 sites not significantly different
Average volume of runoff higher for swine manure than for dairy manure
dairy swine water
Median Plot with 95.0% Confidence Intervals
Liquid Applied
0
100
200
300
400
Run
off V
olum
eRunoff volume – all plots – median
& 95% confidence intervals
Results (cont.)140 m3/ha resulted in significantly more
runoff than lower two rates (97 & 47 m3/ha)Applic. rate 140 m3/ha; runoff = 963 mLApplic. rate 94 m3/ha; runoff = 253 mLApplic. rate 47 m3/ha; runoff = 97 mL
Results (cont.)Pre-tillage did not lead to a “significant”
reduction in the volume of liquid runoff Mean runoff - tilled sites was 309 mLMean runoff - un-tilled sites was 523 mLSimilar for individual sites, for individual
liquids and for each application rateImpact of vegetative cover?
Results (cont.)After simulated rainfall, Runoff Volume:
Influenced by site (more at Site 2), but not by slope
Influenced by liquid application rate – the higher the initial rate, the more rainfall runoff
Not influenced by initial liquid applied
ConclusionsLowest application rate met NMA
standards in all cases and highest rate exceeded in all cases
Lots of variability in runoffNo runoff on 25% of plotsRunoff highest for steepest slope (15.1%)
ConclusionsMore runoff for Swine manure (DM=2.5%)
than Dairy manure (DM=7.4%)Nutrients in runoff similar to applied liquidFollowing simulated rainfall, nutrients in
runoff much lower than initial liquids
This yearSlope
Plots 1 m wide by 4 m long – manure on 3 m length
FundingOntario Ministry of Agriculture, Food &
Rural Affairs – Nutrient Management Research Program
Questions
