• Effects of Seeding Rate on Dry Matter Yield of Two Forage Rape Varieties

      Panciera, Michael T.; Gavlak, Raymond G. (Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, 1991-03)
      Husby and Krieg (1987) reported that average Alaskan forages were deficient in energy for beef cattle and protein levels were marginal for growing animals. Both the energy and protein of Alaskan forages are low for lactating dairy cows (Brundage and Herlugson, 1984). Energy and protein concentrates are imported to Alaska from elsewhere in the U.S. High transportation costs make these imported feedstuffs expensive for Alaskan livestock producers. Brassica crops, such as rape (Brassica riapus L.) and turnips (B. rapa L.) have been widely studied as forage crops because they have the potential to produce high yields of excellent quality forage. Jung et al. (1986) demonstrated this potential when they reported that Brassica spp. yielded 4-7 tons DM/A and the forage was highly digestible (80-90% in vitro dry matter digestibility). Crude protein was relatively low for turnip roots (8-12%), but top growth was high (up to 27%). Lambert et al. (1987) found that the quality of Brassica spp. was too high for optimum performance of growing lambs. They reported that it was necessary to include some coarse feed, such as grass hay, to increase the fiber content in the diets of these animals. The potential of Brassica crops has been investigated in Alaska (Mitchell and Krieg, 1985; Panciera et al., 1990). The yield and quality of these crops in Alaska were similar to the levels observed in the Lower 48 states. Basic agronomic information is needed in order to develop management recommendations for Brassicas in Alaska. Research is underway to define the nitrogen and phosphorus fertilizer requirements (Panciera etal., 1990). This report summarizes the results of a two year study concerning the effects of seeding rates on dry matter yields of two Brassica hybrids.
    • Evaluation of Forage Legume Potential at Fairbanks, Point Mackenzie, and Soldotna

      Panciera, Michael T.; Sparrow, Stephen D.; Gavlak, Raymond G.; Larson, Warren E. (Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska Fairbanks, 1990-06)
      Forage legumes have a high crude protein content and some residual nitrogen from these crops can be utilized by other species that follow legumes in crop rotations. Irwin (1945) compiled the results of early research covering a wide range of legumes, both annual and perennial, at several locations within Alaska, but neither the yields nor the persistence of these crops were comparable to native and introduced grasses. Recommended legumes included field peas and vetches in combination with cereal grains and either alsike or sweetclover in combination with bromegrass for silage (Sweetman et al., 1950). Perennial legume yields (0.5 to 1.9 tons per acre) were low when compared to perennial grasses at the Matanuska Research Farm in southcentral Alaska (Klebesadel, 1980,1983). These low yields were attributed to poor winterhardiness and consequent winterkill of most of the legumes. Formation of ice sheets, direct exposure to lethal temperatures (due to lack of snow cover), and desiccation reduce the ability of perennial legumes to survive winters in southcentral Alaska (Klebesadel, 1974). Yield potentials for perennial grasses may exceed 4.5 tons per acre (Mitchell, 1982), while forage legumes may produce from 0.5 to 2.4 tons per acre in research studies and demonstrations (Klebesadel, 1980; Mitchell, 1986). Husby and Krieg (1987) reported average crude protein contents for Alaska hays to be in the range of 8.3 to 11.8%. Changes in the production potential of Alaskan dairy cattle have effectively redefined the quality of forage that must be produced for the dairy industry. Current milk production potential for Alaska dairy cattle (14,800 lb/yr) requires high concentrations (>16%) of crude protein in the ration (Brown et al., 1989; NRC, 1988). On a dry matter yield basis legumes do not compare well with grasses, but high crude protein content and the cost of protein supplements in Alaska justify further research with both annual and perennial leguminous forage crops. Experiments were conducted to evaluate forage legumes for yield, quality, and persistence potential at three locations in Alaska. Preliminary results from these experiments are presented.