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Regression of Nitrogen Uptake on Nitrogen Added from Four Sources Applied to Grass 1
Author(s) -
Scarsbrook C. E.
Publication year - 1970
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1970.00021962006200050019x
Subject(s) - loam , diammonium phosphate , nitrogen , forage , agronomy , nitrate , ammonium nitrate , ammonium , chemistry , phosphate , urea , zoology , environmental science , fertilizer , soil science , biology , soil water , organic chemistry
Research was conducted to evaluate efficiencies of N fertilizers by comparing slopes of N uptake on N applied regression equations. Ammonium nitrate (33.5‐0‐0), diammonium phosphate (21‐23‐0), urea (45‐0‐0), and ureaammonium phosphate (33‐9‐0) were surface applied at four rates of N to Coastal bermudagrass on Norfolk sandy loam and to Pensacola bahiagrass on Boswell fine sandy loam. Relative efficiencies for N recovery were determined by comparison of the slopes (b) of the equations. The highest average efficiency (b = 0.80) was obtained with ammonium nitrate on bermudagrass. Values of b were similar for all sources of N on bahiagrass. There was a straight line relationship when dry forage produced (y) was plotted against N uptake (x). The equations were y = 1,500 ‐f 48x and y = 3,000 ‐j‐ 34x for bahiagrass and bermudagrass, respectively. These differences in slopes of the equations reflect the differences both in N contents and yields of the forage.