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Fig. 3. Nitrogen concentrations on different dates for (a) coastal bermudagrass, (b) Pensacola bahiagrass, (c) buffalograss, (d) sideoats grama, and (e) blue grama. The regressions are compared in (f). "T" designates the Temple, TX location, "M" designates the Maysfield, TX location, and "W" designates Wills Point, TX location. Symbols represent different years at each location as T 1998 (solid circles), T 1999 (open circles), T 2000 (solid diamond), T 2003 (open diamond), T 2005 (solid square), M 2005 (open square), W 2003 (solid triangle), W 2004 (open triangle), and W 2005 (solid squares). The fit equations (indicated by the solid lines) are coastal bermudagrass: Y = 0.0010616 + 36649.5 X–3.0745) n = 22; r2 = 0.78); bahiagrass: Y = 0.00107 + 1389.64 X–2.4625 (n = 21; r2 = 0.93); buffalograss: Y = 0.0095 + 19.77 X–1.500 (n = 10; r2 = 0.72); sideoats grama: Y = 0.0136 + 309500 X–3.742 (n = 11; r2 = 0.68); blue grama: Y = 0.0206 + 8876.6 X–3.227 (n = 11; r2 = 0.17). For (f), regression symbols are coastal bermudagrass (open circle), bahiagrass (solid circle), buffalograss (solid diamond), sideoats grama (open diamond), and blue grama (solid squares).
