Table 4: Summary of the effect of fertilizer-phosphorus (P) source on aboveground tissue properties for rice grown in a P-deficient, silt-loam soil under flood-irrigated conditions in the greenhouse. Least square means are reported, with n = 4 observations for each fertilizer-P source treatment, expect for ECST, for which n = 3 observations due to missing data from one dead plant.

Plant Property†

P-value

Fertilizer-P Source†

Overall mean

ECST

CPST

MAP

DAP

TSP

RP

UC

Aboveground DM (kg m-2)

0.02

2.0 a‡

1.3 b

2.7 a

1.9 a

2.1 a

2.3 a

2.2 a

-

Aboveground DM concentration

N (%)

0.03

2.1 ab

2.8 a

1.6 b

3.0 a

2.0 ab

1.6 b

1.4 b

-

P (%)

0.61

0.17

0.17

0.16

0.18

0.17

0.14

0.15

0.16

K (%)

0.24

0.33

0.74

0.32

0.53

0.45

0.43

0.42

0.46

Mg (%)

0.92

0.42

0.41

0.40

0.37

0.39

0.42

0.39

0.40

Ca (%)

0.92

0.50

0.53

0.56

0.56

0.56

0.60

0.50

0.54

Fe (g kg-1)

0.08

0.19

0.32

0.25

0.21

0.20

0.21

0.17

0.22

Mn (g kg-1)

0.88

1.9

2.1

2.1

1.8

2.0

2.2

1.8

2.0

Zn (mg kg-1)

0.11

52.4

44.4

51.7

40.3

54.8

40.6

45.4

47.1

Aboveground DM uptake

N (g m-2)

0.01

41.7 abc

28.1 d

42.3 ab

52.8 a

38.9 bc

35.7 bcd

30.3 cd

-

P (g m-2)

0.02

3.3 a

2.0 b

4.3 a

3.6 a

3.5 a

3.2 a

3.4 a

-

K (g m-2)

0.68

6.5

7.2

8.8

8.9

9.0

10.1

9.5

8.6

Mg (g m-2)

0.30

8.4

5.7

10.6

7.6

8.3

9.5

8.5

8.4

Ca (g m-2)

0.35

10.1

7.7

14.6

11.8

12.2

13.8

11.0

11.6

Fe (g m-2)

0.05

0.38 b

0.34 b

0.63 a

0.42 b

0.43 b

0.45 ab

0.36 b

-

Mn (g m-2)

0.45

3.8

2.9

5.4

3.9

4.5

5.0

3.9

4.2

Zn (mg m-2)

0.03

106.8 ab

60.5 c

138.5 a

78.2 bc

118.2 ab

91.4 abc

96.2 ab

-

†Dry matter (DM), electrochemically precipitated struvite (ECST), chemically precipitated struvite (CPST), monoammonium phosphate (MAP), diammonium phosphate (DAP), triple superphosphate (TSP), rock phosphate (RP), and unamended control (UC); ‡Means in a row followed by different letters are different at P ≤ 0.05.