TX-53F Haby 07 Annual Rpt.pdf

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TX-53 the cooler spring and fall temperatures compared to summer. Tifton 85 produces its highest yields during warm weather when adequate moisture is available. In an above normal rainfall year, 120 lb of N/acre applied for each harvest failed to significantly increase bermudagrass DM yield compared to the 60 lb N/acre rate applied for each harvest. Increasing the K rate as K 2 O to 134 lb/acre significantly increased yield the first harvest. In the second and fifth harvests and total yield, DM production was significantly increased by 268 lb K 2 O/acre. In the third and fourth harvests made following above-normal rainfall in July and August, DM yield was optimized at the 402 lb K 2 O/acre treatment. There were no statistically significant increases in yield among K sources at the first, fourth, and fifth harvests. Dry matter yield was significantly increased by application of KMag+KCl in the second harvest, indicating a response to S or Mg, and by ACT 62D+KCl in the third harvest and in total yield. Statistically significant interactions of N and K on DM yield occurred in the third and fifth harvests (P= 0.05) and in the first and fourth harvests and total yield (P = 0.01). No interactions between N and K occurred in the second harvest. Nutrient concentrations in plants and soils that were not available in the preliminary report are reported in this completed report of the study conducted in 2007. Plant analysis data begin on page 5. Table 1. Rainfall, treatment, and harvest history of site- 2007 † . Apr. May June July Aug. Sept. Oct. Nov. 1 N applied .15 .45 2 .24 .84 3 .83 .08 4 .04 5 1.61 .42 6 3.98 Harvest 5 7 8 N applied 9 N & 1st ½ K § .40 10 11 12 Limed ‡ Harvest 4 13 .03 14 1.15 1.96 N applied 15 .20 .82 16 1.41 .22 17 .09 .01 18 19 .14 20 .04 1.04 21 .29* .33 .79 22 .60* .23 .64 23 .07* .47 24 .05* .20 2.13* 25 .03* 1.68 26 Mowed .25 1.52 27 .50 .23 28 Harvest 2 Sampled soil, 6 in. 29 N & 2 nd ½ K 30 1.35 Harvest 3 31 Harvest 1 2.33 .47 Total 2.64 7.92 12.03 3.00 1.12 1.47 2.13 * Rainfall measured at Center head quarters, ~ one mile from research site; other measurements on site. 2
TX-53 † Nitrogen rates of 60 and 120 lb of N applied per acre for each of five harvests ‡ 2.1 tons ECCE 72 Franklin limestone applied to whole research site area. § Applied one-half seasonal K rate plus 120 lb P 2 O 5 and 32.31 lb Mg/ac. Table 2. Rates of urea, mono-ammonium phosphate, muriate of potash, KMag, and KMag+P in grams † . Treatment Urea 11-52-0 KCl KMag ACT 62D 60 lb N/ac 1 141.1 432.6 0 0 0 2 141.1 432.6 209.3 0 0 3 141.1 432.6 7.46 550.6 0 4 131.7 0 94.0 0 865.2 5 141.1 432.6 418.6 0 0 6 141.1 432.6 216.7 550.6 0 7 131.7 0 303.3 0 865.2 8 141.1 432.6 627.9 0 0 9 141.1 432.6 426.0 550.6 0 10 131.7 0 512.6 0 865.2 120 lb N/ac 11 385.6 432.6 0 0 0 12 385.6 432.6 209.3 0 0 13 385.6 432.6 7.46 550.6 0 14 376.1 0 94.0 0 865.2 15 385.6 432.6 418.6 0 0 16 385.6 432.6 216.7 550.6 0 17 376.1 0 303.3 0 865.2 18 385.6 432.6 627.9 0 0 19 385.6 432.6 426.0 550.6 0 20 376.1 0 512.6 0 865.2 † Grams of material applied to 10 x 18 ft plots as randomized treatments numbered 1 through 20 for each of four replications. Table 3. Tifton 85 bermudagrass dry matter (DM) response to K rates and KMag, ACT62D+KCl at two N rates on a limed, acid Darco loamy fine sand on the Coastal Plain of eastern Texas in 2007. N Bermudagrass yield by harvest date and total for season rate † May 31 June 28 July 30 Sept. 12 Nov. 6 Total yield lb/ac ----------------------------------------------DM, lb/ac----------------------------------------------- 60 1,403 ns ‡ 3,245 ns 3,059 ns 3,055 ns 1,342 ns 12,104 ns 120 1,468 3,368 3,090 3,329 1,203 12,458 K 2 O rate § 0 620 b 1,597 c 1,428 c 1,617 c 581 c 5,843 c 134 1,423 a 3,162 b 2,881 b 3,079 b 1,061 b 11,605 b 268 1,583 a 3,630 a 3,225 b 3,343 b 1,398 a 13,179 a 402 1,572 a 3,698 a 3,667 a 3,679 a 1,588 a 14,204 a K Source KCl 1,466 ns 3,214 b 3,037 b 3,384 ns 1,269 ns 12,371 b KMag+KCl 1,468 3,565 a 3,024 b 3,303 1,402 12,762 b ACT 62D+KCl 1,644 3,710 a 3,711 a 3,414 1,376 13,855 a C.V. 18.9 14.5 16.1 11.9 22.8 11.9 Interactions N rate X N rate X N rate X N rate X N rate X K rate K rate K rate K rate K rate P = 0.01 P = 0.05 P = 0.01 P = 0.05 P = 0.01 † N rates applied at green up and after each of the first four harvests. Each regrowth received N rates. ‡ ns = non-signif. diff.; values in a column and treatment group followed by a similar letter are not significantly different statistically. § Averaged over N rate and K source Averaged over N rate and K 2 O rate 3
Page 1: TX-53 Evaluation of KMag and KMag+P
Page 5 and 6: TX-53 bermudagrass. This carried ov
Page 7 and 8: TX-53 Table 10. Tifton 85 bermudagr
Page 9 and 10: TX-53 Table 14. Tifton 85 bermudagr
Page 11: TX-53 Table 18. Soil pH, P, K, Ca,

TX-53F Haby 07 Annual Rpt.pdf

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