1. South Tobacco Creek Watershed
BMP3,4 c)
BMP3,5
BMP2,3
BMP1
MS9
MS13 b) a)
Alberta
Manitoba
Saska-
tchewan
BMP2,3
Annual
crop
Forage
Grazing land
or Pasture
Trees
Water
Others
Figure 1. a) Location of the two sub-watersheds and their land use in 2002; b) Land use at the Madill sub-watershed in 2008; and c) Land use at the Steppler sub-watershed in 2008 and BMPs implemented at the Steppler watershed since (Codes for the BMPs are listed in Table 1).

2. Madill / Control watershed Steppler / Treatment watershed
Figure 2. Share of different forms of P and N in snowmelt and rainfall events in the total N and P exports, respectively, for the whole study period (1999 – 2008) at the Madill and Steppler watershed.

3. b) TN export (Ln(g ha-1)), all runoff events
a) TP export (Ln(g ha-1)), all runoff events
Steppler / Treatment watershed value (Y)
c) TP FWMC (Ln(mg L-1)), all runoff events
d) TN FWMC (Ln(mg L-1)), all runoff events
Madill / Control watershed value (X)
Pre-period (calibration)
Pre-period regression line
Post-period (BMP implementation)
Post-period regression line
Figure 3. Simple regression analyses of TP and TN exports and Flow-Weighted-Mean-Concentrations (FWMCs) showing the effects of BMP implementation without accounting for the effects of hydrology variations.

4. a) N input, all fields
b) P input, all fields
c) N input, annual cropped fields
d) P input, annual cropped fields
e) N removal, all fields
f) P removal, all fields
g) N removal, annual cropped fields
h) P removal, annual cropped fields
i) N budget, all fields
j) P budget, all fields
k) N budget, annual cropped fields
l) P budget, annual cropped fields
Pre period
Post period
Madill Steppler
Kg ha-1 yr-1
+7NS
-26†
+0NS
-5**
+14NS
-16NS
+4NS
-4*
+12NS
-20NS
+2NS
+1NS
-2NS
-14NS
-0NS
-4NS
-45*
-1NS
-6**
+16NS
-12NS
+3NS
-4†
Figure 4. N and P input, removal and budget estimated from land use survey data for the Madill and Steppler watershed.