Ar. Overman, COUPLING AMONG APPLIED, SOIL, ROOT, COMPONENTS FOR FORAGE CROP PRODUCTION, Communications in soil science and plant analysis, 26(7-8), 1995, pp. 1179-1202
This analysis establishes linkage among (a) applied nutrients nitrogen
(N), phosphorus (P), and potassium (K), (b) available soil nutrients,
(c) root dry matter and nutrient content, (d) top dry matter and nutr
ient content, and (e) leaf area and carbon dioxide (CO2) concentration
. It was previously shown that (a) and (d) are coupled by logistic equ
ations with a common response coefficient c between dry matter and pla
nt nutrient uptake with each applied nutrient. As a consequence of the
common c, it has been shown that dry matter and plant nutrient remova
l are coupled by a hyperbolic equation. Furthermore, a model has been
developed which includes N, P, and K as inputs. In the present work, (
a) and (b) were coupled by a logistic equation as were (a) and (c). It
was then shown that plant nutrient removal was coupled to available s
oil nutrients through a hyperbolic equation. The hyperbolic relationsh
ip was also shown to link dry matter between roots and tops, as well a
s plant N removal between roots and tops. As a consequence of the resu
lts above, it was then concluded that root nutrient content is related
to available soil nutrient through a hyperbolic equation. The detaile
d mechanism of this coupling was not identified. Leaf area of soybeans
followed a hyperbolic relationship with CO2 concentration in the cano
py.