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TECHNIQUES FOR REMOTELY MONITORING CANOPY DEVELOPMENT AND ESTIMATING GRAIN YIELD OF MOISTURE STRESSED CORN (LANDSAT, SENSED)
Abstract
Studies were conducted during 1981 and 1982 on three corn (Zea Mays L.) hybrids with different canopy architectures to determine the effect of moisture stress on canopy reflectance and agronomic parameters. The major study objectives were: (1) to develop a statistical base for designing future remote sensing field experiments; (2) to develop prediction models for estimating canopy agronomic parameters (such as leaf area) which minimize the influence of the soil background but which respond in a relatively sensitive manner to crop development; and (3) to develop a model using reflected and emitted radiation for remotely estimating grain yields of moisture stressed corn. Reflectance measurements in the Landsat MSS and Thematic Mapper wavebands, and agronomic and soil moisture measurements, were conducted weekly. Five independent data sets (one for bare soil, two for corn, and two for soybean) were used to evaluate the performance of leaf area index prediction models. The term log(TM4/TM3) appeared in the most unbiased Thematic Mapper models (TM4 = 0.76-0.90 (mu)m; TM3 = 0.63-0.69 (mu)m). Five corn and three soybean prediction models using Thematic Mapper wavebands were selected. The most unbiased LAI prediction model using the MSS bands was based on the Kauth and Thomas (1976) greenness transformation. The Thematic Mapper models were more sensitive and less biased than the MSS models. The MSS models are superior for use over several different crops, however. Leaf area variations accounted for virtually all variability in canopy reflectance data. Seasonal effects on canopy reflectance due to water stress (other than LAI reductions) were undetectable. Prediction equations for phytomass components such as stalk weights did not work well on an independent data set. Remote estimates of grain yields were complicated by differences in vegetative vigor and yield potential among hybrids. Periodic measurements of mid-day canopy temperatures are essential for characterizing moisture stress severity.
Subject Area
Agronomy|Remote sensing
Recommended Citation
GARDNER, BRONSON REA, "TECHNIQUES FOR REMOTELY MONITORING CANOPY DEVELOPMENT AND ESTIMATING GRAIN YIELD OF MOISTURE STRESSED CORN (LANDSAT, SENSED)" (1983). ETD collection for University of Nebraska-Lincoln. AAI8412302.
https://digitalcommons.unl.edu/dissertations/AAI8412302