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Full-Text Articles in Life Sciences
Evapotranspiration Information Reporting: I. Factors Governing Measurement Accuracy, Richard G. Allen, Luis S. Pereira, Terry A. Howell, Marvin E. Jensen
Evapotranspiration Information Reporting: I. Factors Governing Measurement Accuracy, Richard G. Allen, Luis S. Pereira, Terry A. Howell, Marvin E. Jensen
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
More and more evapotranspiration models, evapotranspiration crop coefficients and associated measurements of evapotranspiration (ET) are being reported in the literature and used to develop, calibrate and test important ET process models. ET data are derived from a range of measurement systems including lysimeters, eddy covariance, Bowen ratio, water balance (gravimetric, neutron meter, other soil water sensing), sap flow, scintillometry and even satellite-based remote sensing and direct modeling. All of these measurement techniques require substantial experimental care and are prone to substantial biases in reported results. Reporting of data containing measurement biases causes substantial confusion and impedance to the advancement of …
Improving In-Season Nitrogen Recommendations For Maize Using An Active Sensor, J. Schmidt, D. Beegle, Q. Q. Zhu, R. Sripada
Improving In-Season Nitrogen Recommendations For Maize Using An Active Sensor, J. Schmidt, D. Beegle, Q. Q. Zhu, R. Sripada
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
An active crop canopy reflectance sensor could be used to increase N-use efficiency in maize (Zea mays L.), if temporal and spatial variability in soil N availability and plant demand are adequately accounted for with an in-season N application. Our objective was to evaluate the success of using an active canopy sensor for developing maize N recommendations. This study was conducted in 21 farmers’ fields from 2007 to 2009, representing the maize production regions of east central and southeastern Pennsylvania, USA. Four blocks at each site included seven sidedress N rates (0–280 kgNha−1) and one at-planting N …