The nursery and greenhouse industry requires precise methods to schedule irrigations, since current practices are subjective and contribute to water and nutrient runoff. Capacitance sensors were calibrated to precisely estimate substrate water content, matric potential, and pore water electrical conductivity (EC) in five soilless substrates. Regression coefficients (R2) ranged from 0.29–0.88 and 0.16–0.79 for water content in 5-cm and 20-cm column heights; matric potential R2 ranged from 0.10–0.98 and 0.79–0.98, respectively. Pore water EC calibrations were investigated, contrasting two sensor types and two prediction models. Results were applied to an empirical greenhouse dataset. Better precision and accuracy were achieved with ECH2O-TE sensor and Rhoades model. Capacitance sensors provide precise estimates of plant-available water in most soilless substrates, while pore water EC accuracy and precision depends on the sensor-model combination. These results will enable growers to precisely schedule irrigations based on water content and pore water EC.
|Advisor:||Lea-Cox, John D.|
|Commitee:||Ristvey, Andrew G., Ross, David S.|
|School:||University of Maryland, College Park|
|Department:||Natural Resource Sciences|
|School Location:||United States -- Maryland|
|Source:||MAI 48/06M, Masters Abstracts International|
|Subjects:||Horticulture, Plant sciences, Soil sciences|
|Keywords:||Capacitance, Electrical-conductivity, Irrigation, Real-time, Sensor, Substrate|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be