Theme 22: Grazing Management
Description
Five rest periods were imposed from April to May on a mixed pasture of two ryegrass (Lolium multiflorum Lam.) varieties and white clover (Trifolium repens L.). The rest period starting dates were: April 4, April 18, May 2, May 16, and May 30, for rest periods 1, 2, 3, 4, and 5, respectively. The total area allocated to the experiment was 1.1 ha, which was divided into 22 pastures. The experimental design used was a split-plot. Rest period was assigned to the main plot, grass to the subplot and legume to the subsubplot. The pastures were “mob-grazed” by cattle from 1 to 4 days to a prescribed residue level. The number of tillers per 0.25 m2 decreased linearly with advanced rest periods, at rates of approximately 40 tillers/0.25 m2/week. The percentage of tillers with seed heads increased linearly with advanced rest periods. The percentage of tillers with ripe seeds increased with later rest periods and reached 98% by rest period 5. The decrease in length of seed head probably was responsible for the decrease in seed weight/tiller. However, estimates indicated that because of the increase in percentage of tillers with ripe seeds with later rest periods about 100, 83, and 103 kg/ha of ripe seeds were produced in rest period 3, 4, and 5, respectively. This amount of seed produced is more than enough for a self-reestablishment of the pasture for the following winter.
Included in
Effect of Five Different Rest Periods on Tiller Regrowth of Ryegrass
Five rest periods were imposed from April to May on a mixed pasture of two ryegrass (Lolium multiflorum Lam.) varieties and white clover (Trifolium repens L.). The rest period starting dates were: April 4, April 18, May 2, May 16, and May 30, for rest periods 1, 2, 3, 4, and 5, respectively. The total area allocated to the experiment was 1.1 ha, which was divided into 22 pastures. The experimental design used was a split-plot. Rest period was assigned to the main plot, grass to the subplot and legume to the subsubplot. The pastures were “mob-grazed” by cattle from 1 to 4 days to a prescribed residue level. The number of tillers per 0.25 m2 decreased linearly with advanced rest periods, at rates of approximately 40 tillers/0.25 m2/week. The percentage of tillers with seed heads increased linearly with advanced rest periods. The percentage of tillers with ripe seeds increased with later rest periods and reached 98% by rest period 5. The decrease in length of seed head probably was responsible for the decrease in seed weight/tiller. However, estimates indicated that because of the increase in percentage of tillers with ripe seeds with later rest periods about 100, 83, and 103 kg/ha of ripe seeds were produced in rest period 3, 4, and 5, respectively. This amount of seed produced is more than enough for a self-reestablishment of the pasture for the following winter.
