Research Progress Report, No. 2

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