Dallisgrass yield, quality and nitrogen recovery responses to nitrogen and phosphorus fertilizers1
作者:
D.L. Robinson,
K. G. Wheat,
N.L. Hubbert,
M.S. Henderson,
H.J. Savoy,
期刊:
Communications in Soil Science and Plant Analysis
(Taylor Available online 1988)
卷期:
Volume 19,
issue 5
页码: 529-542
ISSN:0010-3624
年代: 1988
DOI:10.1080/00103628809367957
出版商: Taylor & Francis Group
关键词: soil fertility;plant nutrition;nutrient content;nutrient concentration;forage quality;forage digestibility
数据来源: Taylor
摘要:
Nitrogen applications to dallisgrass grown on Olivier silt loam, an Aquic Fragiudalf, increased forage yield, forage digestibility, nutrient concentrations and nutrient contents as N rates increased to 896 kg ha‐1. Expressing yield as a function of N application rate resulted in quadratic prediction equations that accounted for 75 to 98% of the variability in yield during five years. Eighty‐six percent of the maximum yield was obtained during the five years at 448 kg of N ha‐1. Plant concentrations of N, Ca and Mg were increased more than concentrations of the other macronutrients as N rates increased. Plant contents of N, Ca and Mg in the forage increased 4.0, 3.2 and 3.5‐fold as N rates increased to 448 kg ha‐1, while that of P, K and S increased 2.5 to 2.8‐fold. Residual N accumulations in the soil profile were apparent at the 896 kg ha‐1rate at the end of the growing seasons but were not detected the following March, indicating N losses by leaching and/or denitrification occurred at that N rate. Phosphorus applications increased forage P concentrations but did not increase forage yield nor available P levels in the surface 15 cm of soil. Maximum yields were obtained at forage P concentrations and Bray No. 2 soil P levels as low as 2.0 g kg‐1and 17 mg kg‐1, respectively.
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