Alfalfa and Coastal bermudagrass response to nitrogen and row spacing on an acid, sandy East Texas soil /
The benefits of growing legumes in a mixed stand with hics.
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Summary: | The benefits of growing legumes in a mixed stand with hics. non-legumes has been reported by many researchers. However, few experiments have been conducted to determine the elects of alfalfa [Medicago sativa (L.)] row spacing and N fertilization on the yields of mixtures of alfalfa and Coastal bermudagrass [Cynodon dactylic (L.) Pers.]. Even fewer studies have determined the effect of alfalfa row spacing in combination with bermudagrass on nitrogen fixation and transfer. A field experiment was conducted to determine the effects of alfalfa row spacing and fertilizer N rate on dry matter yields of the two species. This experiment utilized the fourth through the sixth years of alfalfa production and was conducted near the Texas A&M University Agricultural Research and Extension Center at Overton, Texas on a Darco loamy tine sand (Grossarenic Paleudult). 'Alfagraze' alfalfa grown at four row spacings of 23, 46, 69, and 91 cm in a Coastal bermudagrass meadow comprised the main plots. Nitrogen was applied to -1 f h harvest of bermudagrass. In subplots at rates of 0, 28, 56, 84, and 1 12 kg N ha for each harvest of bermudagrass. In the same field experiment, the elect of alfalfa row spacing on N fixation and transfer was 15 l baled microplots located within each zero N-rate subplot. evaluated utilizing N- a Nitrogen fixation and transfer rates were quantified for the four row spacings using the '5N isotope dilution method. A11 treatments were replicated four times. The experiment was harvested when alfalfa was at l 0% bloom stage. Alfalfa and total forage yields increased with increasing N rate. Yield increases, however, were insufficient to onset the cost of fertilization at most N rates. Bermudagrass dry matter yields were not affected by N rate. Neither alfalfa nor total abrade yields were significantly affected by legume row spacing. Bermudagrass was least competitive at 23-cm row spacings of alfalfa, but was not competitive at any row spacing. Residual soil NO3- increased with increasing N rate. The percentage of N in alfalfa from biological fixation was 88%, 84%, and 82% in 1994, 1995, and 1996, respectively. The total quantity of fixed N ranged from 80 to 220 kg N -1 -1 de ending on row spacing and year. Nitrogen transfer from alfalfa to the associated bermudagrass accounted for 66% (first year), 43% (second year), and 28% j (third year) of the bermudagrass' total N content. The quantities of N transferred ranged from 2 to 17 kg N ha depending on row spacing and year. |
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| Item Description: | "Major subject: Soil Science". Vita. |
| Physical Description: | xiii, 78 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references: pages 73-77. |