Premium
Adventitious Roots, Tillers, and Grain Yields of Spring Wheat as Influenced by N‐P Fertilization 1
Author(s) -
Black A. L.
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/agronj1970.00021962006200010011x
Subject(s) - loam , human fertilization , fertilizer , agronomy , grain yield , nitrogen , biology , zoology , chemistry , horticulture , soil water , ecology , organic chemistry
Factorial combinations of concentrated superphosphate at rates of 0, 22, 45, 90, and 180 kg/ha of P and ammonium nitrate at rates of 0, 45, and 90 kg/ha of N were broadcast on a Williams loam soil and incorporated with a tandem disk just before seeding spring wheat ( Triticum aestivum L., ‘Fortuna’). Samples of roots and tops taken at the end of tillering revealed that most of the effect of P and N‐P fertilization was accounted for by changes in plant morphology. Tillers per plant (T) were positively correlated with adventitious roots per plant (R), [T = 1.21 + 0.23R, r 3 = 0.96]. Heads per ha (H) were linearly related to adventitious roots per plant (R), [H = 1.99 + 0.24R, r 3 = 0.94], and to tillers per plant (T), [H = 0.89 + 1.00T, r 3 = 0.88]. Number of heads per ha accounted for 97% of the yield variance associated with fertilizer treatments. Number of kernels per head and kernel weights were not significantly influenced by N and P fertilization. The regression of grain yield on number of adventitious roots per plant accounted for 93% of the variations in grain yield associated with fertilizer treatments. Grain yields increased from 1984 to 2706 kg/ha (29.5 to 40.2 bu/A) when 45 kg/ha of P was added alone and to 3306 kg/ha (48.2 bu/A) when 45 kg/ha of N was also applied. Higher rates of P, with or without added N, failed to further increase grain yield.