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Tyler C. Hoskins, James S. Owen Jr., and Alex X. Niemiera

Maximizing nutrient use efficiency and minimizing leaching and non-point source contributions through runoff have been persistent challenges in containerized crop production that drive both researchers and growers to develop new technologies and

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Janet C. Cole and John M. Dole

These studies were conducted to determine the effect of 1) temperature on P leaching from a soilless medium amended with various P fertilizers, 2) water application volume on P leaching, and 3) various fertilizers on P leaching during production and growth of marigolds (Tagetes erecta L. `Hero Flame'). Increasing temperature linearly decreased leaching fraction; however, total P leached from the single (SSP) or triple (TSP) superphosphate-amended medium did not differ regardless of temperature. Despite a smaller leaching fraction at higher temperatures and no change in the total P leached, P was probably leached more readily at higher temperatures. More P was leached from the medium amended with uncoated monoammonium phosphate (UCP) than from the medium containing polymer-coated monoammonium phosphate (CTP) at all temperatures, and more P was leached from UCP-amended medium at lower temperatures than at higher temperatures. More P was leached from TSP- than from SSP-amended medium and from UCP- than from CTP-amended medium regardless of the water volume applied, but leachate P content increased linearly as water application volume increased for all fertilizers tested. Plant dry weights did not differ regardless of P source. Leachate electrical conductivity (EC) was lower with TSP than with SSP. Leachate EC was also lower with CTP than with UCP. A higher percentage of P from controlled release fertilizer was taken up by plants rather than being leached from the medium compared to P from uncoated fertilizers.

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Andrew G. Ristvey, John D. Lea-Cox, and David S. Ross

hypothesize that current N and P application rates to many ornamental species in container production exceed normal plant N and P growth requirements resulting in low uptake efficiencies and excessive nutrient loss through leaching. A review by Chen et al

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Juan Carlos Díaz-Pérez and Touria E. Eaton

United States, eggplant is often produced with high levels of irrigation water (above the rate of ETc) and N fertilizer, resulting in water waste and N leaching. Excessive irrigation rate not only wastes water, but may also result in reduced yields in

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Cody J. Stewart, S. Christopher Marble, Brian Jackson, Brian J. Pearson, P. Christopher Wilson, and Dwight K. Lauer

100:0, 80:20, and 60:40 and found that although water holding capacity increased with increasing peatmoss percentage, there was no effect on creeping woodsorrel germination. Leaching of herbicides in different growing substrates has also been

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Amanda Bayer, John Ruter, and Marc W. van Iersel

fertilizer out of concern that lower fertilizer applications could negatively impact growth ( Owen et al., 2008 ; Tyler et al., 1996 ). The combination of excessive irrigation and high fertilizer rates often leads to significant leaching of fertilizers

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Lea Corkidi, Donald J. Merhaut, Edith B. Allen, James Downer, Jeff Bohn, and Mike Evans

leaching ( Juntunen et al., 2002 ; Million et al., 2007 ). A number of Best Management Practices have been proposed to maximize production and minimize water contamination from runoff and leaching losses. These practices vary with particular nursery

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Tim R. Pannkuk, Jacqueline A. Aitkenhead-Peterson, Kurt Steinke, James C. Thomas, David R. Chalmers, and Richard H. White

Excessive losses of nitrogen (N), orthophosphate (P), and DOC from soil by leaching is indicative of breaks in their respective nutrient cycles. Losses of these nutrients are typically caused by management practices or natural disturbances in the

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Jeff B. Million and Thomas H. Yeager

routinely conducted to account for changing production conditions (e.g., growth flushes, pruning, spacing), then LF testing can help account for variability in water needs throughout the container nursery. Routine leaching fraction testing coupled with

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Edward F. Gilman, Thomas H. Yeager, and Diane Weigle

Columns (4 × 15 cm) of incubated (25C, 7% volumetric moisture) milled cypress [Taxodium distichum (L.) L. Rich] wood chips received 180 mg of each ionic form of N applied to the surface from dry NH4NO3, KNO3, or (NH4)2SO4 and were leached daily with 16 ml deionized water (pH 5.5). After 10 days, >85% of applied N leached from the columns in all treatments. After 25 days, all N leached from the NH4NO3 and KNO3 treatments, and 93% leached from the (NH4)2SO4 treatment. In subsequent experiments, columns received 360 mg N from NH4NO3 and were leached daily with either 16, 32, 48, or 64 ml of deionized water for 50 days. The rate of N leaching increased with increasing water application rate, although total N leached per column was similar for all water rates after 25 days. Columns that received 45, 90, 180, or 360 mg N/column were leached daily with 16 ml of deionized water. Nitrogen concentrations in the leachate ranged from 3406 ppm \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\mathrm{-}\mathrm{N}\) \end{document} and 2965 ppm \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{4}^{+}\mathrm{-}\mathrm{N}\) \end{document} at day 5 for the 360-mg rate to 3 and 5 ppm, respectively, at day 35 for the 45-mg rate. In all experiments with NH4NO3, more \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\mathrm{-}\mathrm{N}\) \end{document} leached than \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{4}^{+}\mathrm{-}\mathrm{N}\) \end{document} and more \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\mathrm{-}\mathrm{N}\) \end{document} leached than applied, indicating vitrification occurred. \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{4}^{+}\mathrm{-}\mathrm{N}\) \end{document} and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\mathrm{-}\mathrm{N}\) \end{document} broadcast over cypress wood chips in the landscape would leach quickly into the soil.