Table 5 The effects of treatment with humic acid or fulvic acid and different rates of the recommended dose (RDP) of phosphorus fertilizer on biological yield (Ton/ha) and harvest index of barley cultivar Giza 123 in the seasons 2018/2019 and 2019/2020

HA + 100% RDP

11.65 ± 0.69 a

11.85 ± 0.54 a

42.77 ± 0.66 a

42.83 ± 0.02 abcd

HA + 75% RDP

11.42 ± 0.67 a

11.61 ± 0.53 ab

41.54 ± 0.73 ab

41.67 ± 0.00 d

HA + 50% RDP

11.19 ± 0.53 ab

11.37 ± 0.51 ab

40.36 ± 0.01 c

40.41 ± 0.03 e

HA + 0% RDP

10.73 ± 0.50 abc

10.90 ± 0.49 ab

37.65 ± 0.01 d

37.60 ± 0.48 f

FA + 100% RDP

10.59 ± 0.50 abc

10.76 ± 0.49 abc

42.88 ± 0.03 ab

42.82 ± 1.13 cd

FA + 75% RDP

10.21 ± 0.49 abcd

10.38 ± 0.47 abc

42.84 ± 0.03 ab

42.88 ± 1.07 a

FA + 50% RDP

9.83 ± 0.47 bcde

10.00 ± 0.46 bcd

42.77 ± 0.81 b

42.79 ± 0.59 abc

FA + 0% RDP

9.09 ± 0.43 def

9.24 ± 0.42 de

42.71 ± 0.04 ab

42.70 ± 0.04 bcd

100% RDP

9.52 ± 0.46 cdef

9.68 ± 0.44 cde

42.83 ± 0.01 ab

42.91 ± 0.64 abc

75% RDP

8.91 ± 0.43 ef

9.06 ± 0.41 de

42.83 ± 0.03 ab

42.78 ± 0.63 abc

50% RDP

8.30 ± 0.39 fg

8.44 ± 0.38 ef

42.73 ± 0.02 ab

42.88 ± 0.67 ab

0% RDP

7.08 ± 0.34 g

7.20 ± 0.33 f

42.82 ± 0.04 ab

42.94 ± 0.88 ab