99906 Harvest Stubble Height and K Fertilization Affect Performance of Jiggs and Tifton 85 Bermudagrasses.
Poster Number 339-1413
See more from this Division: C06 Forage and Grazinglands
See more from this Session: Forage and Grazinglands Poster I
Tuesday, November 8, 2016
Phoenix Convention Center North, Exhibit Hall CDE
Abstract:
Lack of maintenance fertilization has been implicated in perennial grass stand decline. Dairy production in the Gulf Coast region relies on warm-season grass hay production, where K extraction through biomass removal is significant. An experiment evaluated K fertilization and cutting height effects on herbage harvested, cover, and K removal of Jiggs [Cynodon dactylon (L.) Pers.] and ‘Tifton 85’ [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] bermudagrasses. Treatments were two entries, two stubble heights (8 and 16 cm), and three K2O fertilization rates (0, 20, 40 kg ha-1 harvest-1). Defoliation occurred every 28 d, resulting in four to five harvests in each of two growing seasons. Plots received 60 kg N ha-1 harvest-1. Herbage harvested was greater in the 8- than the 16-cm treatment (8050 and 7330 kg ha-1, respectively), and increased linearly (p< 0.01) from 7040 to 8130 kg ha-1 as K2O fertilization increased from 0 to 40 kg ha-1. Jiggs had greater cover than Tifton 85 after Year 1 (93 and 76%, respectively). Increasing K fertilization increased plant K concentration in 2014 (linear, p< 0.01; quadratic, p< 0.05; 15, 18, 19 g kg-1) and 2015 (linear, p< 0.01; quadratic, p< 0.01; 13, 21, 25 g kg-1), and also increased K removal in harvested herbage in 2014 (linear, p< 0.05; 104, 141, 149 kg ha-1) and 2015 (linear and quadratic, p< 0.01; 88, 172, 216 kg ha-1). Increasing K fertilization had a positive (linear, p< 0.01; quadratic, p< 0.05) effect on change in soil K concentration over the 2-yr study (-6.0, 5.8, 6.2 kg ha-1). Jiggs and Tifton 85 bermudagrasses are most productive when cut to 8-cm stubble and fertilized with 40 kg K2O ha-1 after each harvest, but plant tissue and soil K concentration changed little with K2O rates above 20 kg ha-1 harvest-1.
See more from this Division: C06 Forage and Grazinglands
See more from this Session: Forage and Grazinglands Poster I