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KirnakHalil1998 cmr.pdf (7.03 MB)

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Developing a Theoretical Basis for Demand Irrigation of Acer Rubrum

Kirnak, Halil
http://rave.ohiolink.edu/etdc/view?acc_num=osu1392735898

Abstract Details

1998, Doctor of Philosophy, Ohio State University, Agricultural and Extension Education.
A lysimeter study was conducted to determine evapotranspiration (ET) rates of Red Maple (Acer Rubrum) under field conditions in August and September, 1997. The average daily measured ET for the plant for two months was 998.75 g. This measured ET was compared against Fynn, Stanghellini and Penman’s evapotranspiration models which overestimated actual ET rates by 7.0, 10.16 and 25.70% respectively. Simple linear regression analysis showed that a solar radiation or a VPD based stochastic ET model could be successfully used to predict ET in terms of R2 value of 0.875 and 0.684 respectively. A tension-based, automatic irrigation system was scheduled by a Q-COM controller using a micro-irrigation technique. Plants were irrigated at a potting medium matric potential of 6-10 kPa. Comparison between tension-based irrigation and lysimeter experiments demonstrated the usefulness of the tension-based irrigation scheduling in nursery application. There was no drainage during the experimental periods of irrigation scheduling and average biomass production (wet basis) was approximately 2 kg per tree per month. A closed-loop, feedback control system monitoring real-time medium tension in the pot was developed to schedule irrigation for nursery plants. The model performed the pot medium water balance and evaluated impacts of water stress on the plant by using reference set points. The calibration and validation of the model was done using experimental data collected between August 26 - September 6, 1997 and September 7 - September 22, 1997 respectively. Multivariable, first and second order regression models with an R2 of 0.883 and 0.899 respectively showed that the first order multiple linear regression model was adequate to demonstrate effects of climate factors on measured ET. The most important input climate factors affecting ET at the 90% confidence level were leaf temperature, media-water tension, and solar radiation based on the first order linear multiple regression model. Single-factor, one-way analysis of variance (ANOVA) showed that plant growth medium tension was not highly correlated with ET at the 95% confidence level. Tensions above 12 kPa may have reduced transpiration rate and initiated plant stress as indicated by canopy leaf temperature which temporarily exceeded ambient air temperature during high radiation periods.
Ted H. Short (Advisor)
Harold M. Keener (Committee Member)
Robert C. Hansen (Committee Member)
Daniel A. Herms (Committee Member)
210 p.
Agricultural Engineering

Recommended Citations

Citations

  • Kirnak, H. (1998). Developing a Theoretical Basis for Demand Irrigation of Acer Rubrum [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392735898

    APA Style (7th edition)

  • Kirnak, Halil. Developing a Theoretical Basis for Demand Irrigation of Acer Rubrum. 1998. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1392735898.

    MLA Style (8th edition)

  • Kirnak, Halil. "Developing a Theoretical Basis for Demand Irrigation of Acer Rubrum." Doctoral dissertation, Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392735898

    Chicago Manual of Style (17th edition)

osu1392735898
171
© 1998, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.