A field experiment was carried out to study the effect of irrigation pI nt to attain
sou moisture status of 75, 100 and 125 % available water (AVV) under two irrigation
systems: drip and furrow on status of macro nutrients in soil and maize (Zea mays cv
Giza 602) (at flowering, 60 days after planting; and harvest, 120 days after planting). Increased AW decreased available-N particularly with the furrow syste . The 125
% AW uecreased available N In soil at flowering by 28.8 % immediately beneath the
dripper, corresponding of 10 and 25 cm from the dripper were 27.7 and 48.6 %
respectively. WIth furrow irrigation the decrease was 35.3 %. Similar trend occvrred at
harvest. Avaitable-N were higher with drip than with the furrow system. Available-N
increased with distance from the dripper and decraase with depth. Increased soil moislure was associated with increased available-P particularly
with furrow system. Available-P increased with increase in irrigation leve and 100;
125 % AW gave 8.7 and 81.7 % more avaiiable-P than the 75 % AW treatmenl, in the
surface layer immediately beneath dripper at flowering. Comparable val es for the
furrow were 30.9 and 49.5 % in the same order. A Similar trend occurred t harvest.
Available-P was higher under furrow system that under drip and ayailable-P
decreased going away from the dripper point in both vertical and horizontal directions.
With furrow values decreased with depth. Increasing soil moisture level was associated with increasing available-K in $0;1
particularly with the furrow system. Available-K in soil was higher under fu row than
under drip system, with a tendency of decreasing away from the dnpper's poi t in both
vertical and horizontal directions. Avallable-K at the furthest point from the dripper's
pOint decreased that located Immediately beneath the dripper's point. Similar trend
was occurred at harvest. Shoot dry yield was grealer at 100 % AW in relation to eilher 75 % or 125 % AW. Indicating that 100 % AW was the most appropriate AW. Shoot dry weight at flowering
was higher than at harvest by about 3, 3 and 3.3 limes under drip sy lem for
treatments 1, 2 and 3 respectively. Corresponding values for furrow wera 2.8, 3.7 and
3.4 limes in the same order. Shoot dry yield with drip was greater than with th furrow.
Shoot dry yield with the drip syslem was greater lhan with tha furrow. Similar trends
were recorded at harvest. NPK-uptake was Increased as soil moisture Incraased. NPK-uptake with drip
system were greater than with furrow. Values of all Ihe studied characters were higher at flowering stage as compared
with that at harvest. Drip irrigation showed superior values for yield, as well a uptake
of N, P and K along with avaJiable-N.