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Comparative Growth Analysis of Cool‐ and Warm‐Season Grasses in a Cool–Temperate Environment
Author(s) -
Belesky David P.,
Fedders James M.
Publication year - 1995
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1995.00021962008700050034xdup
Subject(s) - temperate climate , perennial plant , agronomy , growing season , productivity , biology , environmental science , ecology , economics , macroeconomics
Using both cool‐season (C 3 ) and warm‐season (C 4 ) species is a viable means of optimizing herbage productivity over varying climatic conditions in temperate environments. Despite well‐documented differences in water, N, and radiation use, no consistent evidence demonstrates productivity differences among C 3 and C 4 perennial grass species under identical management. A field study was conducted to determine relative growth rates (RGR), nitrogen productivity (NP), and mean radiation productivity (RP) (dry matter production as a function of incident radiation) of cool‐ and warm‐season grasses managed identically. Results were used to identify management practices that could lead to optimal productivity in combinations or mixtures of cool‐ and warm‐season grasses. Dry matter yields of warm‐season grasses equaled or surpassed those of cool‐season grasses, despite a 40% shorter growth interval. Certain cool‐ and warm‐season grasses appear to be suitable for use in mixtures, based on distribution of herbage production; however, actual compatibility may be altered by defoliation management. Relative growth rates varied among years and were about 40% lower for canopies clipped to a 10‐cm residue height each time 20‐cm of growth accumulated compared with other treatments. The RGR of warm‐season grasses was twice that of cool‐season grasses. Nitrogen productivity (g DM g −1 N d −1 ) and mean radiation productivity (g DM MJ −1 ) for warm‐season grasses was also more than twice that of cool‐season grasses. Radiation productivity of cool‐season grasses was dependent on N, while this was not always the case for warm‐season grasses. The superior production capability of certain warm‐season compared with cool‐season grasses in a cool–temperate environment can be sustained under a range of defoliation treatments and demonstrates suitability for use in frequently defoliated situations.