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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.

Abstract

The pistachio (Pistacia vera L.), characteristically a biennial bearer, produces its most extensive shoot growth in years of heavy crop production. Whereas levels of total sugars in bark and wood of bearing and nonbearing branches were similar throughout the year, starch levels tended generally to be higher in nonbearing than in bearing branches. Consequently, nonbearing branches one year gave rise to heavy crops the next and, beacuse of greater quantities of reserve foods, also produced extensive shoot growth. Bearing branches of that same year, .however, produced few or no nuts the next and, because of lesser quantities of reserve foods, produced markedly less shoot growth. No relationship between total nitrogen level and shoot growth or fruiting was evident.