Fodder beet is considered as one of the best fodder crops for livestock
under Egyptian conditions. This study investigates the effect of fertilization
with phosphoric acid at different both rates and timing of application on fodder
beet productivity, soil P and pH below the emitters under drip irrigation
system. The experimental site was located at EI-Maghara Research Station of
Desert Research Center at North Sinai. Phosphoric acid was applied through
drip irrigation system at rates equivalent to 0, 10, 20, 30, 40 and 50 kg
P₂0s/feddan (concentration of acid should not exceed 300 mllm3 of water
during growth). These treatments were splitted and added each 2 weeks and
4 as timing factor of application. Fresh yield of roots and leaves beside root length and circuit increased
significantly with elevatinq phosphene acid rate. The most pronunced
response was from 40 Kg P₂0slfed. The most effective frequeet til'l'lin~ of
application was, proven to be each 2 weeks. Phosphorus concentration in tlhe
soil was significantly affected by different levels of phosphoric, acid. The
higl'Ter content of P under emitter is attributed te the accumulation of P during
tme. fetrtilizafio'r'l cycle. Soil acidification caused by phosphoric acid occurred to a large extent
in the volume of soil below the emitters. Acidification was greater at the
higher rates of the acid treatments. Under desert condition and calcareous
soil, fertilization with phosphoric acid as a fertilizer source is suggested to be
practiced repeatedly for its convenience, advantages and efficiency.