Comparison of Comparative Yield and Stubble Height for Estimating Herbage Standing Crop in Annual Rangelands

• Published in: Rangeland ecology & management Vol. 59; no. 4; pp. 438 - 441
• Main Authors: George, Melvin R., Barry, Sheila J., Larson, Stephanie R., McDougald, Neil K., Ward, Theresa A., Harper, John M., Dudley, Dennis M., Ingram, Roger S., Laca, Emilio A.
• Format: Journal Article
• Language: English
• Published: Lawrence Elsevier Inc 01.07.2006; Alliance Communications Group; Elsevier Limited
• Subjects: Average linear density; Botanical composition; Calibration; double sampling; dry matter accumulation; equations; Erodium cicutarium; estimation; Estimation methods; filaree; forage; forbs; Grasses; height; mathematical models; Modeling; monitoring; Pastures; Range management; rangelands; residual dry matter; seasonal variation; standing crop; stubble; Sward; Technical Note; Vegetation; yields; California; double sampling; filaree; monitoring; residual dry matter
• ISSN: 1550-7424; 1551-5028; 1551-5028
• DOI: 10.2111/04-166R2.1

We compared calibration equations for estimating herbage standing crop (HSC) from comparative yield (CY) rank or stubble height (SH) to determine 1) if CY rank is a better estimator than SH of standing crop, 2) if addition of SH to CY rank will improve the estimation of standing crop, 3) if there is a seasonal effect on CY rank or SH, and 4) if botanical composition influences the prediction of HSC from CY. The results of this study indicate that CY is a slightly better predictor of HSC than is SH. Addition of SH to CY did not improve the prediction of HSC. Models that predict HSC from CY in summer were weaker than models for winter, early spring, and late spring. Thus the CY method can be used with confidence throughout the year. The presence of filaree (Erodium cicutarium L.) in winter and early spring resulted in steeper calibration equations than were present in nonfilaree quadrats.