Details

Autor(en) / Beteiligte

• Anderson, William
• Parker, Myron B.
• Knoll, Joseph Edward
• Lacy, R. Curt

Titel

Fertilization Ratios of N–P2O5–K2O for Tifton 85 Bermudagrass on Two Coastal Plain Soils

Ist Teil von

• Agronomy journal, 2016-07, Vol.108 (4), p.1542-1551

Ort / Verlag

The American Society of Agronomy, Inc

Erscheinungsjahr

2016

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Bermudagrass [Cynodon dactylon (L.) Pers.] is widely grown throughout the southeastern United States and many other countries for forage. Tifton 85, a hybrid between C. dactylon and C. nlemfuensis, is currently the recommended cultivar for grazing and hay. This study was conducted to determine the response of Tifton 85 to six rates of N fertilization (224, 336, 448, 560, 672, and 784 kg ha−1) and three rates of PK fertilization (50, 100, and 150% replacement of P and K removal) on two different soils, Carnegie (fine, kaolinitic, thermic Plinthic Kandiudult) and Fuquay (loamy, kaolinitic, thermic Arenic Plinthic Kandiudult), for 4 yr. In a randomized split‐plot design, whole plots were N rates with PK rates randomized within whole plots. The optimal fertilization rate to provide maximum profits was determined. Though yields began to level off only at the 560 kg ha−1 N application rate, rates from 224 to 448 kg ha−1 N with 100% replacement of P and K uptake resulted in maximum economic return. At these N rates, based on actual nutrient uptake, the N–P2O5–K2O ratio for fertilization of Tifton 85 should be approximately 4–1–5. At 336 to 448 kg ha−1 N, a grower could expect approximately 19.6 to 23.0 Mg ha−1 yr−1 hay at 150 g kg−1 moisture. Crude protein (CP) concentration and in vitro dry matter digestibility (IVDMD) of the harvested forage both responded positively to increasing rates of N application beyond the economically optimum rates. Core Ideas Split plot design with N, P, K rates on Tifton 85 bermudagrass show yields level off at 560 kg ha−1. Rates of 224 to 336 kg ha−1 N and 100% replacement of P K had maximum rate of economic return. Recommended ratio of fertilizer is N–P2O5–K2O ratio for fertilization of Tifton 85 should be approximately 3–1–4 at the lowest rate and 4–1–5 at the higher rate. Protein and in‐vitro dry matter digestibility of forage increased with higher N application.