Date of Award
Master of Science
John H. Reynolds
Henry Fribourg, Edward Clebsch
The relation of various nitrogen levels, stubble heights, andcutting frequencies to the dry matter production of orchardgrass(Dactylis glomerata L.) was studied at Knoxville, Tennessee. There Were twelve combinations of these factors used in the experiment.The orchardgrass was harvested either four or eight times at 3.8-cm or 10.2-cm stubble heights, and with nitrogen fertilization rates of 224,448, and 672 kg/ha applied in two equal parts. Regrowth stubblecores were taken at three-week intervals and stubble weights were sampled on June 5, July 25, and September 5, in 1967. During 1968,all plots received the same treatment of 224 kg/ha of nitrogen and 7.0-cm stubble height.
There was a significant difference in yield during 1967 with a range of 7.21 to 10.49 metric tons per hectare. The highest-producing treatment combination was 448 kg/ha of nitrogen, 3.8-cm stubble height, and 4-cutting frequency. Little difference in vigor was observed between treatments. This may have been due to lower-than-normal temperatures and higher-than-normal precipitation in July.
Differences in the yield of the first cutting of the residual year (1968) were small with nitrogen and cutting frequency effects not significant. The effect of cutting height was reversed from 1967,with the tall stubble significantly better in production in 1968.The stubble weight samples, regrowth core weights, last-6-weeks yield of 1967, and 1967 total yield were used in a simple linear correlation with the 1968 first-cutting forage yield. None of the factors correlated were significant.
The results indicate that intensive management is not extremely harmful to the capability of a first year orchardgrass stand to produce forage when cool and wet summer weather occurs. There was a lower yield from the orchardgrass fertilized with 672 kg/ha of nitrogen thanwith J4U8 kg/ha. Residual effects on the first cutting of the second year were small.
Laaker, Kenneth, "Forage production of orchard grass (Dactylis glomerata L.) under several cutting management and nitrogen fertilization regimes. " Master's Thesis, University of Tennessee, 1968.