Overseeding with Cool-season Annual Forages Reduces Early Spring
Bermudagrass Regrowth
John R. Bow & James P. Muir
Texas Agricultural Experiment Station at Stephenville
INTRODUCTION
Dairies in north-central Texas containing high-phosphorus soils resulting from the application of waste
water and manure can recycle nutrients by over-seeding Coastal and Tifton 85 bermudagrass (Cynodon
dactylon (L.) Pers.) fields with cool-season annual forages. Ryegrass (Lolium multiflorum Lam.),
barley(Hordeum vulgare L.), rye (Secale cereale L.), triticale (Triticum secale L.), oats (Avena sativa L.),
wheat (Triticum aestivum L.), hairy vetch (Vicia villosa Roth), burr medic (Medicago polymorpha L.),
arrowleaf clover (Trifolium vesiculosum Savi.), rose clover (Trifolium hirtum All.), crimson clover
(Trifolium incarnatum L.), turnips and rape (Brassica spp.) were evaluated for winter forage yields and
spring bermudagrass yields.
OBJECTIVES
Recycle soil-P with an additional winter forage crop
Provide high quality winter/spring greenchop
Trade-offs in winter vs. spring bermudagrass yields and phosphorus
MATERIALS & METHODS
RESULTS
Species were no-tilled into 1.5 X 5 m plots in early fall of 2004 and 2005. Cool-season grass and brassica
plots received 56 kg ha-1 nitrogen in mid winter. Species were individually harvested in the spring when
the cool-season grasses were in boot stage and the forbs flowered. The bermudagrasses were harvested
with the first cutting (if present) and again when the bermudagrass regrew. Rainfall totals from October
through May were 589 mm in year 1 (2004-2005) and 359 mm in year 2 (2005-2006).
Table 1. Cool-Season Species no-till drilled into Tifton 85
Ryegrass
Barley
Rye
Triticale
Oats
Wheat
YEAR 1
Cool-season forages
-1
-1
P Kg/ha
DM Kg/ha
*2584
CDE **10
3857
ABC
13
3725
ABC
13
3288
BCD
11
4112
AB
12
3065
BCDE
8
DM Kg/ha
3203
2048
1637
2000
2133
1891
Hairy Vetch
Arrowleaf clover
Crimson clover
Rose Clover
Burr Medic
4850
895
2276
1777
0
A
FGH
EDF
EFG
H
13
3
7
5
0
1235
2194
3243
1776
6366
Turnips
Essex Rape
Control (volunteer)
394
839
2793
GH
GH
BCDE
2
4
6
5103
5700
6137
Ryegrass
Barley
Rye
Triticale
Oats
Wheat
Hairy Vetch
Arrowleaf clover
Crimson clover
Rose Clover
Burr Medic
Turnips
Essex Rape
Control (volunteer)
YEAR 2
Cool-season forages
-1
-1
P
Kg/ha
DM Kg/ha
3242
AB
13
3843
A
13
2943
ABC
11
2049
CDE
7
3204
AB
9
2538
BC
7
DM Kg/ha
1594
1193
1372
1639
1785
1824
-1
-1
Tifton 85
-1
P Kg/ha
B
6
BC
6
BC
4
BC
5
BC
7
BC
6
0
C
2
BC
9
B
10
BC
6
A
13
0
A
10
A
14
A
13
Tifton 85
-1
P Kg/ha
CD
3
D
3
CD
3
CD
4
CD
6
CD
5
Dry matter yields for the cool-season forages over-seeded in Tifton
85 were affected by year x species interaction (P < 0.0001) and in
Coastal differed by species in year 1 only. Tifton 85 production
was reduced by over-seeding in both years (P < 0.0001 and P <
0.005, respectively) as was Coastal in year 1 (P = 0.0023).
Table 2. Cool-Season Species no-till drilled into Coastal
Tifton 85
1st cut
% loss
48
67
73
67
65
69
80
64
47
71
-4
17
7
0
Tifton 85
1st cut
pH
N
P
K
Ca
Mg
S
Na
Soil test (ppm)
Tifton 85 Coastal
8.2
8.4
27
35
81
188
418
717
2,503
2,706
216
438
17
21
140
203
% loss
54
65
60
53
48
47
Ryegrass
Barley
Rye
Triticale
Oats
Wheat
Hairy Vetch
Arrowleaf clover
Crimson clover
Rose Clover
Burr Medic
Turnips
Essex Rape
Control (volunteer)
Ryegrass
Barley
Rye
Triticale
Oats
Wheat
499
210
393
0
627
E
E
E
E
E
1
1
1
0
3
3794
6531
3790
6511
4967
ABCD
A
ABCD
A
AB
8
27
11
21
10
-10
-89
-10
-88
-44
Hairy Vetch
Arrowleaf clover
Crimson clover
Rose Clover
Burr Medic
1004
170
0
DE
E
E
4
1
0
3970
4316
3456
ABCD
ABC
BCD
8
10
8
-15
-25
0
Turnips
Essex Rape
Control (volunteer)
*Columns of each species differ if letters differ
YEAR 1
Cool-season forages
-1
-1
P Kg/ha
DM Kg/ha
10655
A
41
9219
B
36
7455
C
29
8368
B
33
7807
C
31
7748
C
31
1021
31
273
59
89
0
844
2283
5234
F
F
F
F
F
F
E
D
4
0
1
0
0
0
4
10
20
YEAR 2
Cool-season forages
-1
-1
P
Kg/ha
DM Kg/ha
314
NS
1
1335
NS
5
356
NS
1
146
NS
1
280
NS
1
1343
NS
5
Cool-season forages can recycle an additional 0 to 9 kg
-1
DE
BC
AB
BCD
BC
BCD
720
1028
1689
657
2251
0
2110
2121
3112
E
CDE
BCD
E
AB
B
B
A
P Kg/ha
2
6
7
4
6
5
-1
1
4
5
2
5
0
4
5
7
77
67
46
79
28
32
32
0
Coastal
1st cut
Coastal
DM Kg/ha
999
1071
1091
1249
1083
1082
-1
NS
NS
NS
NS
NS
NS
% loss
70
37
15
45
38
42
P Kg/ha
2
3
3
3
4
3
-1
% loss
12.6
6.3
4.6
-9.3
5.2
5.3
0
0
2
0
1
1258
1140
794
1048
968
NS
NS
NS
NS
NS
3
4
2
3
2
-10.1
0.3
30.5
8.3
15.3
1150
1371
415
NS
NS
NS
6
6
2
1013
893
1143
NS
NS
NS
2
2
3
11.4
21.9
0.0
phosphorus per year.
Growing seasons that have sufficient rainfall to grow cool-season annual forages can result in a loss of Tifton 85 or
Coastal (20-70%) in the first cutting.
Over-seeding is poor investment in dry years.
DM Kg/ha
942
1960
2645
1711
1932
1810
NS
NS
NS
NS
NS
**P Kg/ha -1 a function of yield X concentration
e
-1
ha of
Coastal
0
43
381
0
222
CONCLUSIONS
NS Not Significant
Coastal
1st cut