Leaf Removal to Simulate Grazing of Corn by Lambs
1982
Mulkey, J. R. | Varner, L. W. | Albach, E. L. | Drawe, H. J.
Most of the corn grown in the United States is harvested for grain or silage. Only a small percent is grazed. In corn growing areas where lambs are available, corn might provide some limited grazing without affecting yield. Field experiments (Aridic calciustoll soils) were conducted during 1978–1980 to simulate the grazing of corn by lambs. The lower 2, 4, 6, 8, and 10 leaves were removed at 90 to 100% silking and at 2-week intervals for 6 weeks thereafter. Removing the bottom 10 leaves either at 90 to 100% silking or 2 weeks afterward caused a significant reduction in grain yield, 1,000-kernel weight and number of kernels per ha. No significant yield losses were measured with less severe defoliation or defoliation at later stages of maturity. The data showed that 890 kgha of oven-dried forage could be removed during the first 4 weeks after 90 to 100% silking or 1,284 kgha after 4 weeks from silking without significant yield reductions. At the later stages, protein and P content are below the level required for proper lamb growth. These studies indicate that yield losses can be minimized by restricting leaf removal during and after pollination. However, before this can become an acceptable practice, additional investigations are needed to study the effects that lambs might have on ears, stalks, and soil compaction.
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