TX-53F Haby 07 Annual Rpt.pdf

TX-53
Table 12. Tifton 85 bermudagrass S conc. response to N and K rates and K, Cl, and S sources, 2007.
N rate Plant S concentration †
lb/ac/harv. Harvest 1 Harvest 2 Harvest 3 Harvest 4 Harvest 5 Season avg.
-------------------------------------------------%------------------------------------------------------
60 0.38 0.35 0.33 a 0.32 a 0.27 0.33 a
120 0.37 0.32 0.31 b 0.29 b 0.24 0.31 b
K rate
lb K 2 O/ac
0 0.20 c 0.18 b 0.20 c 0.18 c 0.17 c 0.19 c
134 0.42 a 0.35 a 0.32 b 0.29 b 0.24 b 0.32 b
268 0.38 b 0.34 a 0.33 b 0.32 a 0.27 a 0.33 b
402 0.38 b 0.35 a 0.35 a 0.34 a 0.29 a 0.34 a
K Source
KCl 0.20 b 0.17 c 0.19 c 0.18 c 0.16 c 0.18 c
KMag+KCl 0.49 a 0.36 b 0.33 b 0.28 b 0.25 b 0.34 b
ACT 62D+KCl 0.49 a 0.51 a 0.48 a 0.48 a 0.38 a 0.47 a
R 2 0.97 0.98 0.96 0.97 0.94 0.99
c.v. 8.59 7.88 9.03 9.56 11.56 5.49
† Values in a column/group followed by a dissimilar letter are significantly different statistically (α = 0.05).
Table 13. Tifton 85 bermudagrass S uptake response to N and K rates and K, Cl, and S sources, 2007.
N rate Plant S uptake †
lb/ac/harv. Harvest 1 Harvest 2 Harvest 3 Harvest 4 Harvest 5 Season total
-------------------------------------------------lbs/ac------------------------------------------------
60 5.5 11.7 10.6 10.0 3.8 a 41.6
120 5.6 11.2 10.2 9.8 3.1 b 39.9
K rate
lb K 2 O/ac
0 1.3 b 2.8 c 2.8 d 3.1 d 1.0 d 11.0 d
134 6.0 a 11.2 b 9.4 c 9.0 c 2.6 c 38.1 c
268 6.1 a 12.7 a 11.0 b 10.7 b 3.8 b 44.3 b
402 6.0 a 13.5 a 13.4 a 12.3 a 4.6 a 49.9 a
K Source
KCl 2.9 c 5.5 c 5.9 c 6.2 c 2.1 c 22.7 c
KMag+KCl 7.1 b 12.9 b 9.9 b 9.4 b 3.6 b 42.9 b
ACT 62D+KCl 8.0 a 18.9 c 17.9 a 16.5 a 5.4 a 66.7 a
R 2 0.88 0.94 0.91 0.93 0.84 0.94
c.v. 21.8 16.1 21.4 16.8 30.2 15.3
† Values in a column/group followed by a dissimilar letter are significantly different statistically (α = 0.05).
The Cl concentration tended to decline as the N rate was raised. The only significant decline occurred in
harvest 2 and this carried over to the season average. Chloride uptake was relatively unaffected by N rate
but was significantly lowered in harvest 2. As expected, Cl concentration and uptake increased as the K
application rate was raised. Greater Cl concentrations occurred in the order KCl > ACT 62D+KCl >
KMag+KCl. Chloride uptake changed in the order KCl = ACT 62D+KCl > KMag+KCl. Total Cl uptake
for the season ranged from 17 to 23 lb/ac.
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