12
A. Shaviv
amount leached with EDF (N03-), and about 30% of the amount leached with
CRN ~ 1. Obviously, N uptake is smallest with EDF (N03) All these indicate
that the band application of the CRN and, to some extent, the effect of nitrification
inhibition due to banding are effective in reducing N losses and maintaining high
yield in the light soil.
Table 4. Interactions of nitrification inhibition, fertilizer type, and rate of N release with
soil type under band applications
Factor
Tested
NI
N storage
I
checked I Soil I
texture
factor
I Leached I Volat!. I
N
uptake I N03--N I NH/-N I
- - - - - - - (kg ha-') - - - - - -
Sandy
0.0
124
10
115
32
8
BJ, Soil
loam
0.01
92
12
124
53
8
Inhibitn.
0_1
78
12
119
71
9
Capacity
0.0
12
9
116
149
8
(I mg- I )
Loam
0.01
12
16
122
138
9
0.1
12
19
125
76
67
CRN-N~
24
9
121
48
71
Types of
Sandy
EDF-NH4
92
12
124
53
8
applied
loam
EDF-N03
207
0
78
5
1
fertilizer
CRN-N~
8
6
122
58
94
Loam
EDF-N~
12
16
122
138
9
EDF-N03
7
0
124
147
1
Slow
24
9
121
48
71
Sandy
Moderate
51
11
118
74
34
Rate of
loam
Fast
66
12
121
70
20
N-release
Slow
8
6
121
58
94
Loam
Moderate
11
12
117
93
65
Fast
12
14
120
125
26
In the loam soil, the leaching was significantly reduced in comparison to the
sandy loam. Instead, the storage of N03--N was large, particularly with the soluble
forms of nitrogen, implying that potentially more N is likely to be lost after
harvest. With CRN, large amounts of ammonium were found in the rooting profile
of the two soils, implying that plants were exposed to ammonium-rich nutrition,
which, by itself, offers several agronomic advantages such as increased
bioavailability ofP and higher yields of protein in grain (Shaviv, 1993; 2000).
3.4.3 Significance of Release Rate From a eRN
Simulations were run with three different release rates of CRNs: slow, moderate
and fast. In the sandy loam, the higher the rate ofN-release, the larger the leaching
ofN (Table 4) and nitrate storage in the root zone, whereas the N uptake remains
A. Shaviv
amount leached with EDF (N03-), and about 30% of the amount leached with
CRN ~ 1. Obviously, N uptake is smallest with EDF (N03) All these indicate
that the band application of the CRN and, to some extent, the effect of nitrification
inhibition due to banding are effective in reducing N losses and maintaining high
yield in the light soil.
Table 4. Interactions of nitrification inhibition, fertilizer type, and rate of N release with
soil type under band applications
Factor
Tested
NI
N storage
I
checked I Soil I
texture
factor
I Leached I Volat!. I
N
uptake I N03--N I NH/-N I
- - - - - - - (kg ha-') - - - - - -
Sandy
0.0
124
10
115
32
8
BJ, Soil
loam
0.01
92
12
124
53
8
Inhibitn.
0_1
78
12
119
71
9
Capacity
0.0
12
9
116
149
8
(I mg- I )
Loam
0.01
12
16
122
138
9
0.1
12
19
125
76
67
CRN-N~
24
9
121
48
71
Types of
Sandy
EDF-NH4
92
12
124
53
8
applied
loam
EDF-N03
207
0
78
5
1
fertilizer
CRN-N~
8
6
122
58
94
Loam
EDF-N~
12
16
122
138
9
EDF-N03
7
0
124
147
1
Slow
24
9
121
48
71
Sandy
Moderate
51
11
118
74
34
Rate of
loam
Fast
66
12
121
70
20
N-release
Slow
8
6
121
58
94
Loam
Moderate
11
12
117
93
65
Fast
12
14
120
125
26
In the loam soil, the leaching was significantly reduced in comparison to the
sandy loam. Instead, the storage of N03--N was large, particularly with the soluble
forms of nitrogen, implying that potentially more N is likely to be lost after
harvest. With CRN, large amounts of ammonium were found in the rooting profile
of the two soils, implying that plants were exposed to ammonium-rich nutrition,
which, by itself, offers several agronomic advantages such as increased
bioavailability ofP and higher yields of protein in grain (Shaviv, 1993; 2000).
3.4.3 Significance of Release Rate From a eRN
Simulations were run with three different release rates of CRNs: slow, moderate
and fast. In the sandy loam, the higher the rate ofN-release, the larger the leaching
ofN (Table 4) and nitrate storage in the root zone, whereas the N uptake remains