کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2419939 1552419 2012 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of N fertilisation, leaf appearance and time of day on N fractionation and chemical composition of Lolium perenne cultivars in spring
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Effects of N fertilisation, leaf appearance and time of day on N fractionation and chemical composition of Lolium perenne cultivars in spring
چکیده انگلیسی

New Zealand dairy systems are based on Lolium perenne pastures with low nitrogen use efficiency (NUE) and high urinary N losses. Modelling attempts to provide solutions to improve NUE are limited due to lack of data on pasture N fractions under a range of management situations. The effects of N application (0 or 25 kg N/ha), cultivar (standard and high sugar cultivars), regrowth interval (leaf appearance of 2, 3 and 4 leaf) and time of day (morning or afternoon) on chemical composition and N fractionation of L. perenne were investigated in a field study in early spring. Leaf appearance interval and time of day had the greatest influence on chemical composition and fractionation. Both fraction A (non-protein N) and water soluble carbohydrates increased by 60% between second and fourth leaf appearance (P<0.001) and by 20% between morning and afternoon (P<0.001). Total N and fractions B1 and B2 (soluble true protein) declined during the day and with leaf appearance. Addition of low fertiliser N rates did not alter N fractionation or chemical composition but improved herbage yield. The effects of using a high sugar cultivar were small and inconsistent and differences between cultivars were more closely linked with flowering date. Generally, the relative proportions of N fractions could be altered with management strategies but the overall solubility of N remained high at over 0.85. While management factors play an important role in influencing the quality of herbage and total N relative to carbohydrate, there is little scope to improve NUE by reducing the proportions of soluble N fractions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Animal Feed Science and Technology - Volume 173, Issues 3–4, 11 May 2012, Pages 210–219
نویسندگان
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