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Herbage Yield and Quality of Filegrass as Influenced by N, P, and K Fertilizer Applications 1
Author(s) -
Omaliko C. P. E.
Publication year - 1984
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/agronj1984.00021962007600020008x
Subject(s) - potash , nutrient , dry matter , fertilizer , yield (engineering) , anthesis , zoology , agronomy , chemistry , potassium , nitrogen , mathematics , biology , cultivar , materials science , organic chemistry , metallurgy
The nutrient requirements of filegrass ( Anthephora ampulacea , Stapf and Hubb), a potential pasture species, is hardly known. A greenhouse experiment was conducted to study the effects of applied N, P, and K fertilizers on its herbage yield and quality. Four rates of N (0, 100, 200 and 300 kg N/ha −1 as ammonium sulfate); three rates of P (0, 33, and 66 kg P ha −1 as single superphosphate); and three rates of K (0, 62, and 124 kg K ha −1 as muriate of potash) were applied in solution in all possible treatment combinations (36 treatments). Plants were first harvested when 50% of the primary tillers were at early anthesis, A second harvest was made after 4 weeks of regrowth. Fertilizer application at 100 kg N/ha −1 rate at least doubled filegrass yield (7.4 vs. 14.8 g pot −1 for 0 vs. 100 kg N ha −1 rates). Higher rates of N application gave further significant yield increases (19.4 and 19.9 g pot −1 for 200 and 300 kg N ha −1 , respectively). For the regrowth harvest, yields differed significantly such that 0 < 100 < 200 < 300 kg N ha −1 . Filegrass response to applied N is represented by the following regression equations Y = 9.2 + 0.05 × (for first harvest) and Y = 1.39 + 0.018 × (for second harvest). Applied P and K fertilizers did not significantly affect the dry matter yields and concentration of other nutrients in both the leaf and stem fractions. Applied N at 100 kg ha −1 rate increased N concentration of the leaf fraction but decreased P, Ca, and Mg of the leaf. Higher N rates, however, increased these nutrients in the leaf blade. Nitrogen application, at all rates, increased the stem concentrations of N from 0.49 to 1.20; P from 0.16 to 0.26; K from 0.87 to 1.12; Ca from 0.11 to 0.56 and Mg from 0.06 to 0.19% on dry matter basis. The dry matter digestibility (DMD) values for both leaf and stem fractions were relatively close (62.8 and 53.4%, respectively). The DMD of each fraction was increased by N application from 45.6 to 65.7 in the leaf and stem when the rate was increased from 0 to 300 kg N ha −1 . These results were discussed in terms of herbage production and livestock requirements.