In two seasons (1986/87 and 87/88), phosphorus ferti—
lizer was applied as ordinary calcium superphosphate (OCSP)
mixed with seeds of field beans (Vicia faba L. cv. Giza
2) at rates of 7.0, 10.5 and 14 kg p/fad. (16, 24 and 32
kg P205/fad.), It caused more growth and gave 57 and 14%
mroe yield at the low and high rates than broadcast, and
37 and 19% more yield at the same respective rates than
banding.
Mixing ocsp with seeds has the same advantage as its
banding in keeping the contact of fertilizer with soil
to minimum P fixation. It also has the further advantage
of securing sample P in the vicinity of seeds, and seedling
roots at the earliest possible stage in crop life, both
of which are crucial fer growth and yield. Uptake of N,
P and K as well as seed yield were all increased by this
method.
Under Egyptian conditions of (a)-soils being mostly
clayey or calcareous or both and (b)-OCSP being powdered,
appreciable fixation of P is invevitable; hence, this method
is imperative especially if conditions dictate low rates.
INTRODUCTION
Legume crops including field beans (Vicia faba L.)
need supply of available P for healthy growht and high
yeilds.
Applying (OCSP) up to 10.5 kg P/fad. (24 kg P205)
to beans on a clay loam soil, Roshdy (1975), attributed
the lack of response in seed yield to the ample soil P
(20 ppm Na—bicarbonate extractable). El—Moghraby (1980),
later on, grew beans on the same soil (different field)
and obtained significant response but at tىuch higher rates
of up to 28 kg P/fad.