Estimation of Leaf and Stem Area in the Wind Erosion Prediction System (WEPS)

Autor: Amare Retta, Dean V. Armbrust
Rok vydání: 1995
Předmět:
Zdroj: Agronomy Journal. 87:93-98
ISSN: 1435-0645
0002-1962
DOI: 10.2134/agronj1995.00021962008700010017x
Popis: A process-oriented wind erosion prediction system (WEPS) is being developed. Among the processes to be simulated is the influence of biomass cover in dissipating wind energy at the soil surface. The wind speed profile within the canopy is a function of the distribution of leaf and stem areas by height. Relationships are needed to calculate leaf and stem areas and leaf and stem masses for use in area and mass by height distribution functions. Alfalfa (Medicago sativa L.), corn (Zea mays L.), oat (Avena sativa L.), sorghum [Sorghum bicolor (L.) Moench.], soybean [Glycine max (L.) Merr.], and winter wheat (Tritium aestivum L.) were planted in different years, soil types, and management regimes. The objective was to obtain relationships that could be used to simulate leaf and stem area growth. Measurements were made of leaf and stem areas and leaf and stem masses. Linear and nonlinear regressions of leaf dry weight on leaf area and of stem dry weight on stem area were performed. The linear model fit the leaf data for all crops and also fit the stem data for alfalfa, oat, soybean, and winter wheat, with r 2 values ranging from 0.83 to 0.99. The stem data of corn and sorghum fit the nonlinear model (with r 2 =0.99 and 0.92, respectively). Regression parameters for stem appear to be less affected by environmental factors (e.g., management, different years, varieties, or soil types) than are the regression parameters for leaf. The linear and nonlinear relationships can be used to estimate leaf and stem area growth from their respective masses
Databáze: OpenAIRE
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