Table 2 Change in total P and Olsen-P affected by different fertilization modes in the surface soil layer (0–20 cm) over time.

From: Effects of the continuous use of organic manure and chemical fertilizer on soil inorganic phosphorus fractions in calcareous soil

Items

Treatments

Soil P content (mg·kg−1) over time (years)

2009

2010

2011

2012

2013

Olsen-P

OM

54.96 ± 7.07aA

57.35 ± 9.85aA

62.50 ± 15.28aA

72.74 ± 15.46aA

86.04 ± 14.53aA

CF

55.33 ± 11.41aA

56.44 ± 10.34aA

58.42 ± 13.05aA

65.58 ± 15.10bA

72.40 ± 10.16bB

CK

54.72 ± 8.58aA

51.23 ± 6.42aA

46.22 ± 10.46bB

34.09 ± 10.44cB

19.53 ± 7.42cC

Total P

OM

1327.36 ± 86.45aA

1326.49 ± 72.48aA

1358.36 ± 82.51aA

1402.47 ± 77.52aA

1488.04 ± 105.27aA

CF

1332.46 ± 90.37aA

1325.37 ± 117.33aA

1348.32 ± 134.26bA

1362.41 ± 154.62bB

1392.56 ± 152.30bB

CK

1321.27 ± 45.28aA

1320.48 ± 50.42aA

1321.32 ± 62.37cB

1319.46 ± 66.48cC

1317.70 ± 72.35cC

  1. Note: The different lowercase and uppercase letters in the same column for each parameter indicate a significant difference at the 0.05 and 0.01 levels, respectively.