P rates

ZnSO4∙7H2O

pH

Zn (DTPA)

PBray2

PMehlich1

PFe-strip Pi

(kg∙P2O5∙ha1)

(kg∙ha−1)

(1:1)

(mg∙kg1)

-----------------(mg∙kg1)--------------

0

4.72

4.5

0.52

3.12

2.86

1.33

16

4.72

4.7

0.63

5.44

3.85

1.89

32

4.72

4.6

0.36

12.88

8.24

5.55

64

4.72

4.6

0.20

25.32

21.05

16.24

128

4.72

4.7

0.64

32.25

28.20

22.45

0

0

4.6

0.23

3.34

3.19

1.45

16

0

4.9

0.21

5.94

3.96

2.04

32

0

4.4

0.23

13.45

4.81

5.34

64

0

4.8

0.38

29.23

15.24

13.55

128

0

4.8

0.17

37.52

32.00

22.86