placed on clipping, using it only for calibration and validation within trials.
Nondestructive standing crop estimators are important for efficientThe canopy analyzer (CA) (LI-COR, Lincoln, NE) monitoring of native and agronomic systems. This study evaluated is a fast, nondestructive instrument that indirectly estiplot and pasture estimates of standing crop using LAI-2000, visual mates leaf area index (LAI; Welles and Norman, 1991). obstruction, canopy height, and weighted plate measurements. Research was conducted in Lubbock County, Texas, in 1999 on areas Direct measurements of LAI using the LAI-3000 area dominated by Amarillo fine sandy loam (fine-loamy, mixed, thermic meter (LI-COR, Lincoln, NE) have shown a positive Aridic Paleustalfs). Five hundred plot estimation samples were collinear relationship between leaf area and SC (Engel et lected for each method along 25 transects, and each transect mean was al., 1987). Since the CA measures foliage area per unit used for the pasture estimation trials. Coefficients of determination of ground area, we hypothesized a positive relationship improved as we moved from plot (0.34, 0.85, 0.37, and 0.70) to pasture would exist between CA measurements and SC.(0.67, 0.87, 0.59, and 0.83) estimation for LAI-2000, visual obstruction,