• Perennial Grass and Soil Responses to Four Phosphorus Rates at Point MacKenzie

      Mitchell, Wm. W.; Mitchell, G. Allen; Helm, D. (Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska-Fairbanks, 1987-05)
      Three perennial grasses were established on Kashwitna silt loam at Pt. MacKenzie in 1985 to test their responses to different rates o f phosphorus (P) fertilization. Laboratory studies with a number o f Alaskan soils have indicated strong P-fixation properties for the Pt. MacKenzie soils (Ping and Michaelson 1986, Michaelson and Ping 1986). Earlier work with cereal forages showed responses for barley up to 90 lbs/acre and for oats up to 60 lbs P205/acre (Michaelson et al. 1984). All three perennial grasses [‘Engmo’ timothy (Phleum pratense), ‘Manchar’ bromegrass (Bromus inermis), and reed canarygrass (Phalaris arundinacea)] responsed to P2O5 up to 120 lbs/acre in their establishment year in 1985 (Mitchell and Mitchell 1986). Reed canarygrass significantly outproduced in 1985, yielding over two tons dry matter/acre at the higher fertilizer levels. Bromegrass was the least productive in the establishment year. This report concerns the results obtained in 1986, which constituted the first full harvest year.
    • Phosphorus Rate Effects on Establishment of Perennial Grasses And on Soil Values at Point MacKenzie

      Mitchell, Wm. W.; Mitchell, G. Allen (Agricultural and Forestry Experiment Station, School of Agriculture and Land Resources Management, University of Alaska-Fairbanks, 1986-02)
      This trial concentrates on the effects of varying rates of P with N and K supplied in amounts judged to be ample for establishment of perennial grasses. The results indicated that, by seeding sufficiently early and supplying 90-120 lb P20 5/acre, harvestable amounts of forage could be obtained in the year o f seeding. Reed canarygrass would provide the most forage in the first year; how ever, in previous trials timothy has been more durable and higher yielding over a series of years (Mitchell, in press). Laboratory measurements of crude protein and digestible dry matter indicated the quality of the forage would be good to excellent. The high-yielding reed canarygrass was the lowest in quality but still afforded about 13 per cent crude protein and 60 percent digestible dry matter. The trial is to be continued to determine the cumulative effects of annual fertilizer applications at the same rates on yields and soil test values. A question of immediate concern is the possible effect of promoting high production in the year of establishment on the overwintering characteristics of the grasses.