2019 SWCS International Annual Conference July 28-31, 2019 Pittsburgh, Pennsylvania

2.  Buffalo National River (BNR) established by the
National Park Service in 1972 (Mott and Laurans,
2004).
 Encompasses the Ozark Mountain region of north-
central Arkansas (White, Haggard, and Chaubey,
2003).
 The Nation’s first designated Scenic River.
 Affords numerous recreational and agricultural
activities:
› Swimming, canoeing and hiking
› Forestry, pastureland and livestock/poultry
operations

3. Map courtesy of the Big Creek Research and Extension Team. https://bigcreekresearch.org

5.  Present day applications of swine manure (slurry) to fields within
the BNR watershed:
› Originating from a Concentrated Animal Feeding Operation
(CAFO)
› Used as a fertilizer source
 Can possibly lead to elevated levels of soil phosphorus (P) in
adjacent waterways:
› Base flow/groundwater infiltration
› Surface runoff/storm events
› Influence of grazing/deposition patterns
 Excess P in aquatic systems can be detrimental:
› Promotion of algal blooms
› Reduction of dissolved oxygen
› Decrease in aesthetic qualities

6.  Mount Judea, AR
› Big Creek
› Tributary to the BNR
 Three fields involved in study:
› Field 1
› Field 5a
› Field 12
 All fields in cattle/hay
production
› Fields 1 and 12 receive swine
slurry (since 2014)
› Field 5a receives mineral fertilizer
only
Map courtesy of the Big Creek Research and Extension
Team. https://bigcreekresearch.org

7.  Geo-referenced grid-soil sampling
› 0.5-acre grid
› 2014, 2016 and 2018
 Surface (0-4 inch) and subsurface (to refusal)
samples
› ≈ 160 total sampling sites per sampling year
› Analyzed for soil test P

8.  Statistical analysis
› Paired t-test
› Probability P = 0.05
› JMP version 14.0/Matched Pairs Platform
Location
Soil Depth
(in.)
Number of
Samples 2014
Number of
Samples 2016
Number of
Samples 2018
Field 1 0-4” 71 71 71
Field 5a 0-4” 33 44 44
Field 12 0-4” 40 45 45

9. Site
Soil
Depth
(in.)
2014
Soil Test
P
(mg/kg)
2016
Soil Test
P
(mg/kg)
N for
paired t-
test
Field 1 0-4” 59 a§ 57 a 71
Field 5a 0-4” 45 a 42 a 33
Field 12 0-4” 63 b 104 a 40
§Rows sharing a common letter are not significantly different (P=0.05).

10. Site
Soil
Depth
(in.)
2016
Soil Test
P
(mg/kg)
2018
Soil Test
P
(mg/kg)
N for
paired t-
test
Field 1 0-4” 57 b§ 91 a 71
Field 5a 0-4” 39 b 48 a 43
Field 12 0-4” 104 b 122 a 45
§Rows sharing a common letter are not significantly different (P=0.05).

11. Site
Soil
Depth
(in.)
2014
Soil Test
P
(mg/kg)
2018
Soil Test
P
(mg/kg)
N for
paired t-
test
Field 1 0-4” 59 b§ 91 a 71
Field 5a 0-4” 45 a 50 a 33
Field 12 0-4” 63 b 122 a 40
§Rows sharing a common letter are not significantly different (P=0.05).

12. Field 1 (15.6 acres/6.3 hectares)

14. Field 5a (23.8 acres/9.6 hectares)

16. Field 12 (23.7 acres/9.6 hectares)

17. Note soil test P is already
above 100 mg/kg here. This is
prior to any slurry application to
this field.

18.  No significant increases in soil test P for Fields 1 and 5a
from 2014 to 2016.
› Significant increase in soil test P for Field 12 in 2016
compared to 2014 (P<0.0001).
 Significant increase in soil test P for Fields 1 (P<0.0001),
5a (P=0.0285), and 12 (P=0.0001) from 2016 to 2018.
 Causes for these increases in soil test P for Fields 1, 5a,
and 12 from 2014 to 2018:
› Periodic slurry application to Fields 1 and 12
› Cattle congregation and loafing patterns
› Legacy soil P accumulation over time and mineral fertilizer
applications (Field 5a)

19.  All three fields in this study (1, 5a, & 12) showed a
significant increase in soil test P from 2016 to 2018.
› Due to periodic slurry applications and cow
grazing/deposition
› Applications of mineral fertilizers (legacy soil P)
 Producers from all three fields have been informed:
› Agreed to closely manage cattle congregation patterns
› Agreed to reduce the number of slurry applications to their
respective fields
 Big Creek Research and Extension Team will continue
to ensure the water quality of Big Creek and the BNR:
› Intensive soil and water P monitoring
› Adaptive conservation practices

20.  Mott, D. and J. Laurans. 2004. Buffalo River
Water Management Plan. United States
Department of the Interior. National Park
Service.
 White, K.L., B.E. Haggard, and I. Chaubey.
2004. Water Quality At The Buffalo National
River, Arkansas, 1991-2001. Transactions of the
ASAE. 47(2):407-417.