LENGTH OF LIFE OF ROOTS OF TEN SPECIES OF PERENNIAL RANGE AND PASTURE GRASSES

Abstract

Each species was grown in triplicate lots in containers of large diam. and 28 to 33 inches depth. These were placed in soil in the field (Sept. to April of each year) but in an open greenhouse during summer. A removable extension at the top of each container was filled with sandy loam soil. When removed the soil was easily washed away from the roots but replaced after root-banding. Small bands of very thin pliable tin were placed around a total of 3,424 roots. 97% of the banded roots of Agropyron cristatum survived the first summer and 75% the 1st yr. Survival on Bromus inermis was 92, 84, and 36% at 3 examinations. Survival on Panicum virgatum and Agropyron smithii was, after the 2d summer, 100 and 42%, respectively. After 3 growing seasons 81% of the roots on Andropogon furcatus survived, but none on Elymus canadensis. Losses in all spp. were gradual and after 3 growing seasons survival of roots was as follows Bouteloua gracilis 45%, B. curtipendula 14, and Andropogon scoparius and Stipa spartea each 10%. Average number of roots produced by individual plants varied from 175 to 882 after 3 summer''s growth. Losses among the banded roots often amounted to only 2-8% of the total number of living roots. Roots of grasses of various ages were also banded in the prairie with losses after 2 summers of 23 to 45%. Losses from seedlings of Bromus inermis and Agropyron cristatum clipped at 2 inches height at 10-day intervals were 15 and 73%, respectively, but only 0-3% on unclipped controls. Similar clipping of the tops of transplanted sods of Andropogon furcatus and A. scoparius resulted in losses of the new roots of 45 and 64%, respectively. The unclipped controls lost only 3% each.