Agriculture Reference
In-Depth Information
TABLE 6:
Estimated agronomic efficiency (AEN) of applied N depending on the inorganic
fertilizer treatment and the biofertilizer used.
Season
Biofertilizer
treatment **
Inorganic fertilizer treatment *
0% RR
25% RR
50% RR
100% RR
Reference
grain yield
(kg·ha
−1
)
AEN *** (kg grain yield increase kg
−1
N ap-
plied)
2008/09 DS
BG
12
8
9
BN
23
14
8
BS
17
5
9
Control
4062
13
9
6
2009 WS
BG
3
13
5
BN
23
12
8
BS
12
9
9
Control
1902
4
3
3
2010 WS
BG
41
28
13
BN
51
39
16
BS
42
26
15
Control
3389
38
20
15
2010/11 DS
BG
29
19
15
BN
42
24
14
BS
36
23
14
Control
3801
21
15
12
* RR: Recommended rate: 120-60-60 kg N-P
2
O
5
-K
2
O ha
−1
in the DS; 90-30-30 kg N-P
2
O
5
-
K
2
O ha
−1
in the WS; ** Biofertilizer treatments are described in detail in the text; *** For
the estimation of AEN in each experimental season, the grain yield of the treatment without
inorganic fertilizer and biofertilizer (0% RR and Control) was used as reference.
The general effect of inorganic fertilizer was as expected, and grain
yields increased continuously with increasing fertilizer rates (Table 4).
However, the response to inorganic fertilizer was low in the 2008/09
DS and the 2009 WS, as also indicated by the low AEN (Table 5). Good
and economic values for AEN are usually 15-20 kg grain yield per kg
N applied, and, at AEN < 10, inorganic fertilizer use may give negative
