Table 2 Annual P balance over 35-year experimental period (1981–2015).

From: Substituting chemical P fertilizer with organic manure: effects on double-rice yield, phosphorus use efficiency and balance in subtropical China

Item

CK

NK

NPK

NKM

Input (kg hm−2 yr−1)

Fertilizer

0.0

0.0

78.4

0.0

Pig manure

0.0

0.0

0.0

60.6

Output (kg hm−2 yr−1)

Corp removal

17.1

21.7

49.0

37.5

P storage in top soil layer

− 5.8

− 3.6

17.6

0.9

Calculated P loss

− 11.4

− 18.1

11.8

22.1

PRE

  

62.5%

61.9%

  1. CK: unfertilized control; NK: mineral fertilizer NK; NPK: mineral fertilizer NPK; NKM: mineral fertilizer NK combined with pig manure, PRE: phosphorus recovery efficiency.
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