US 2026/0215360 A1Published application

Simplified nitrogen fertilizer rate recommendation method based on nitrogen balance benchmark

AssigneeInstitute of Agricultural Resources and Regional Planning, CAAS

InventorsWencheng DING, Ping HE, Xinpeng XU, Wei ZHOU, Shicheng ZHAO, Shaojun QIU

Life of this patent

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Abstract

A simplified nitrogen fertilizer rate recommendation method based on a nitrogen balance benchmark for rice, maize and rice is provided. The present disclosure provides a nitrogen fertilizer rate recommendation method based on nitrogen balance benchmark. This method only requires knowledge of the crop yield and soil fertility level to recommend nitrogen fertilizer application rates.

Claims3

Dependent claims

A simplified rice nitrogen fertilizer dosage recommendation method based on a nitrogen balance benchmark, comprising following steps:

(1) determining a soil nitrogen supply level of a target field by any one of Method 1, Method 2, Method 3, or Method 4:
Method 1:
determining the soil nitrogen supply level of the target field according to aboveground nitrogen uptake of rice under a nitrogen omission treatment, based on different rice varieties:
Soil
Aboveground nitrogen uptake of
nitrogen
rice under nitrogen omission
supply
treatment (kilograms per hectare (kg/ha))
capacity
Single-season
Middle-season
level
rice
rice
Early rice
Late Rice
Low
<58.2
<78.3
<61.2
<65.4
Medium
58.2-89.0
78.3-109.9
61.2-96.0
65.4-100.2
High
>89.0
>109.9
>96.0
>100.2
Method 2:
determining the soil nitrogen supply level of the target field according to rice yield under the nitrogen omission treatment, based on the different rice varieties:
Soil
nitrogen
supply
Rice yield under nitrogen omission treatment (kg/ha)
capacity
Single-season
Middle-
Early
level
rice
season rice
rice
Late Rice
Low
<4631
<5451
<4167
<4441
Medium
4631-6334
5451-6860
4167-6067
4441-6459
High
>6334
>6860
>6067
>6459
Method 3:
dividing the soil nitrogen supply level of the target field according to soil organic matter content:
Soil
nitrogen
supply
Soil organic matter
Soil hydrolysable nitrogen
capacity
content (grams per
content (milligrams of nitrogen per
level
kilogram (g/kg))
kilogram (mg N/kg))
Low
<10
<100
Medium
10-30
100-180
High
>30
>180
wherein the soil nitrogen supply level uses a soil organic matter content level as a judgment basis, with soil hydrolysable nitrogen as an adjustment factor:
when the soil hydrolysable nitrogen is ≥180 milligrams per kilogram (mg/kg), the soil nitrogen supply level of the low supply capacity is adjusted to the medium supply capacity;
when the soil hydrolysable nitrogen is ≤100 mg/kg, the soil nitrogen supply level of high supply capacity is adjusted to the medium supply capacity;
Method 4:
determining the soil nitrogen supply level of the target field according to soil texture and apparent characteristics:
Soil
nitrogen supply
capacity level
Conditions to be met
Medium
Soil texture:
loam or clay;
Soil color:
gray or brown
High
Soil texture:
loam or clay;
Soil color:
black
Low
The conditions above are not met
(2) determining the nitrogen balance benchmark for the target field according to the soil nitrogen supply level of the target field determined in the step (1) and in combination with a fertilization mode, with reference to a following table:
Nitrogen balance benchmark (kg/ha)
Mechanical
Nitrogen
Conventional
Controlled-
deep
fertilizer
Soil
chemical
release
placement
application
nitrogen supply
nitrogen
nitrogen
of nitrogen
via organic
Straw
capacity level
fertilizer
fertilizer
fertilizer
sources
return
Low
88.6
78.6
71.8
86.8
82.3
Medium
63.9
53.9
47.2
62.1
57.6
High
27.9
18.0
11.2
26.1
21.6
(3) obtaining Ygrain as rice grain yield based on a target yield, and determining the aboveground nitrogen uptake of the rice for the target field according to formula (a-1) or (a-2):
N
uptake
=
N
grain
+
N
straw
;
(
a
-
1
)
wherein:
Nuptake is the aboveground nitrogen uptake of the rice, in kg/ha;
Ngrain is a rice grain nitrogen uptake, in kg/ha;
and
Nstraw is a rice straw nitrogen uptake, in kg/ha;
N
uptake
=
Y
grain
*
X
grain
+
Y
straw
*
X
straw
;
(
a
-
2
)
wherein:
Nuptake is the aboveground nitrogen uptake of the rice, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
Ystraw is rice straw biomass, in kg/ha;
Xgrain is a rice grain nitrogen content, in mg/kg;
and
Xstraw is a rice straw nitrogen content, in mg/kg;
(4) calculating a recommended rice nitrogen fertilizer application rate for the target field according to formula (b):
N
=
N
uptake
+
N
balance
;
(
b
)
wherein, N represents the recommended rice nitrogen fertilizer application rate, in kg/ha;
Nuptake represents the aboveground nitrogen uptake of the rice, in kg/ha;
and Nbalance represents the nitrogen balance benchmark, in kg/ha;
wherein when no measured value is available for the rice straw biomass, the rice straw biomass is calculated according to formula (c):
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
g
⁢
r
⁢
a
⁢
i
⁢
n
*
a
;
(
c
)
wherein Ystraw is the rice straw biomass, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
and a represents a conversion coefficient between the rice grain yield and the rice straw biomass, wherein conversion coefficients for different rice varieties are shown in a table below;
when no measured value is available for the rice grain nitrogen uptake, the rice grain nitrogen uptake is calculated according to formula (d):
N
grain
=
Y
grain
*
b
*
0.001
(
d
)
wherein Ngrain is the rice grain nitrogen uptake, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
and b represents a conversion coefficient between the rice grain yield and the rice grain nitrogen uptake, wherein conversion coefficients for different rice varieties are shown in the table below;
when no measured value is available for the rice straw nitrogen uptake, the rice straw nitrogen uptake is calculated according to formula (e):
N
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
c
*
0.001
;
(
e
)
wherein Nstraw is the rice straw nitrogen uptake, in kg/ha;
Ystraw is the rice straw biomass, in kg/ha;
and c represents a conversion coefficient between the rice straw biomass and the rice straw nitrogen uptake, wherein conversion coefficients for different rice varieties are shown in the table below:
Conversion
Single-
Middle-
coefficient
season rice
season rice
Early rice
Late rice
a
0.90
1.00
0.88
0.94
b
9.0
11.8
11.9
11.5
c
5.5
6.5
7.8
7.5

310 more elements

A simplified maize nitrogen fertilizer dosage recommendation method based on a nitrogen balance benchmark, comprising following steps:

(1) determining a soil nitrogen supply level of a target field by any one of Method 1, Method 2, Method 3, or Method 4:
Method 1:
determining the soil nitrogen supply level of the target field according to aboveground nitrogen uptake of maize under a nitrogen omission treatment, based on different maize varieties:
Soil
Aboveground nitrogen uptake of maize under
nitrogen supply
nitrogen omission treatment (kg/ha)
capacity level
Spring maize
Summer maize
Low
<71.1
<73.1
Medium
71.1-141.7
73.1-146.1
High
>141.7
>146.1
Method 2:
determining the soil nitrogen supply level of the target field according to maize yield under the nitrogen omission treatment, based on the different maize varieties:
Soil
Maize yield under nitrogen
nitrogen supply
omission treatment (kg/ha)
capacity level
Spring maize
Summer maize
Low
<4300
<3738
Medium
4300-8766
3738-7485
High
>8766
>7485
Method 3:
dividing the soil nitrogen supply level of the target field according to soil organic matter content:
Soil
Soil organic
Soil
nitrogen supply
matter content
hydrolysable nitrogen
capacity level
(g/kg)
content (mg N/kg)
Low
<10
<100
Medium
10-30
100-180
High
>30
>180
wherein the soil nitrogen supply level uses a soil organic matter content level as a judgment basis, with soil hydrolysable nitrogen as an adjustment factor:
when a soil hydrolysable nitrogen is ≥180 milligrams per kilogram (mg/kg), the soil nitrogen supply level of the low supply capacity is adjusted to the medium supply capacity;
when the soil hydrolysable nitrogen is ≤100 mg/kg, the soil nitrogen supply level of high supply capacity is adjusted to the medium supply capacity;
Method 4:
determining the soil nitrogen supply level of the target field according to soil texture and apparent characteristics:
Soil
nitrogen supply
capacity level
Conditions to be met
Medium
Soil texture:
loam or clay;
Soil color:
gray or brown
High
Soil texture:
loam or clay;
Soil color:
black
Low
The conditions above are not met
(2) determining the nitrogen balance benchmark for the target field according to the soil nitrogen supply level of the target field determined in the step (1) and in combination with a fertilization mode, with reference to a following table:
Nitrogen balance benchmark (kg/ha)
Mechanical
Nitrogen
Conventional
Controlled-
deep
fertilizer
Soil
chemical
release
placement
application
nitrogen supply
nitrogen
nitrogen
of nitrogen
via organic
Straw
capacity level
fertilizer
fertilizer
fertilizer
sources
return
Low
73.3
61.9
57.5
73.1
62.7
Medium
46.4
35.0
30.6
46.2
35.8
High
12.0
0.6
−3.8
11.8
1.4
(3) obtaining Ygrain as maize grain yield based on a target yield, and determining the aboveground nitrogen uptake of the maize for the target field according to formula (a-1) or (a-2):
N
uptake
=
N
g
⁢
r
⁢
a
⁢
i
⁢
n
+
N
s
⁢
t
⁢
r
⁢
a
⁢
w
;
(
a
-
1
)
wherein:
Nuptake is the aboveground nitrogen uptake of the maize, in kg/ha;
Ngrain is a maize grain nitrogen uptake, in kg/ha;
and
Nstraw is a maize straw nitrogen uptake, in kg/ha;
N
uptake
=
Y
grain
*
X
grain
+
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
X
s
⁢
t
⁢
r
⁢
a
⁢
w
;
(
a
-
2
)
wherein:
Nuptake is the aboveground nitrogen uptake of the maize, in kg/ha;
Ygrain is the maize grain yield, in kg/ha;
Ystraw is maize straw biomass, in kg/ha;
Xgrain is a maize grain nitrogen content, in mg/kg;
and
Xstraw is a maize straw nitrogen content, in mg/kg;
(4) calculating a recommended maize nitrogen fertilizer application rate for the target field according to formula (b):
N
=
N
uptake
+
N
balance
;
(
b
)
wherein, N represents the recommended maize nitrogen fertilizer application rate, in kg/ha;
Nuptake represents the aboveground nitrogen uptake of the maize, in kg/ha;
and Nbalance represents the nitrogen balance benchmark, in kg/ha;
wherein the maize straw biomass is calculated according to formula (c):
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
g
⁢
r
⁢
a
⁢
i
⁢
n
*
a
;
(
c
)
wherein Ystraw is the maize straw biomass, in kg/ha;
Ygrain is the maize grain yield, in kg/ha;
and a represents a conversion coefficient between the maize grain yield and the maize straw biomass, wherein conversion coefficients for different maize varieties are shown in a table below;
the maize grain nitrogen uptake is calculated according to formula (d):
N
grain
=
Y
grain
*
b
*
0.001
(
d
)
wherein Ngrain is the maize grain nitrogen uptake, in kg/ha;
Ygrain is the maize grain yield, in kg/ha;
and b represents a conversion coefficient between the maize grain yield and the maize grain nitrogen uptake, wherein conversion coefficients for different maize varieties are shown in the table below;
the maize straw nitrogen uptake is calculated according to formula (e):
N
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
c
*
0.001
;
(
e
)
wherein Nstraw is the maize straw nitrogen uptake, in kg/ha;
Ystraw is the maize straw biomass, in kg/ha;
and c represents a conversion coefficient between the maize straw biomass and the maize straw nitrogen uptake, wherein conversion coefficients for different maize varieties are shown in the table below:
Conversion
coefficient
Spring maize
Summer maize
a
1.08
0.95
b
10.7
11.9
c
5.6
7.5

305 more elements

A simplified wheat nitrogen fertilizer dosage recommendation method based on a nitrogen balance benchmark, comprising following steps:

(1) determining a soil nitrogen supply level of a target field by any one of Method 1, Method 2, Method 3, or Method 4:
Method 1:
determining the soil nitrogen supply level of the target field according to aboveground nitrogen uptake of wheat under a nitrogen omission treatment, based on different wheat planting regions:
Aboveground nitrogen uptake of wheat under
Soil
nitrogen omission treatment (kg/ha)
nitrogen supply
Northern
Southern
capacity level
planting region
planting region
Low
<49.6
<32.1
Medium
49.6-139.2
32.1-93.5
High
>139.2
>93.5
Method 2:
determining the soil nitrogen supply level of the target field according to wheat yield under the nitrogen omission treatment, based on the different wheat planting regions:
Wheat yield under nitrogen
Soil
omission treatment (kg/ha)
nitrogen supply
Northern
Southern
capacity level
planting region
planting region
Low
<1701
<1098
Medium
1701-5224
1098-3585
High
>5224
>3585
Method 3:
dividing the soil nitrogen supply level of the target field according to soil organic matter content:
Soil
Soil organic
Soil
nitrogen supply
matter content
hydrolysable nitrogen
capacity level
(g/kg)
content (mg N/kg)
Low
<10
<100
Medium
10-30
100-180
High
>30
>180
wherein the soil nitrogen supply level uses a soil organic matter content level as a judgment basis, with soil hydrolysable nitrogen as an adjustment factor:
when a soil hydrolysable nitrogen is ≥180 milligrams per kilogram (mg/kg), the soil nitrogen supply level of the low supply capacity is adjusted to the medium supply capacity;
when the soil hydrolysable nitrogen is ≤100 mg/kg, the soil nitrogen supply level of high supply capacity is adjusted to the medium supply capacity;
Method 4:
determining the soil nitrogen supply level of the target field according to soil texture and apparent characteristics:
Soil
nitrogen supply
capacity level
Conditions to be met
Medium
Soil texture:
loam or clay;
Soil color:
gray or brown
High
Soil texture:
loam or clay;
Soil color:
black
Low
The conditions above are not met
(2) determining the nitrogen balance benchmark for the target field according to the soil nitrogen supply level of the target field determined in the step (1) and in combination with a fertilization mode, with reference to a following table:
Nitrogen balance benchmark (kg/ha)
Mechanical
Nitrogen
Conventional
Controlled-
deep
fertilizer
Soil nitrogen
chemical
release
placement
application
supply capacity
nitrogen
nitrogen
of nitrogen
via organic
Straw
level
fertilizer
fertilizer
fertilizer
sources
return
Low
72.3
61.4
62.9
74.8
63.5
Medium
33.6
22.7
24.2
36.1
24.8
High
−23.3
−34.2
−32.7
−20.8
−32.1
(3) obtaining Ygrain as wheat grain yield based on a target yield, and determining the aboveground nitrogen uptake of the wheat for the target field according to formula (a-1) or (a-2):
N
uptake
=
N
g
⁢
r
⁢
a
⁢
i
⁢
n
+
N
s
⁢
t
⁢
r
⁢
a
⁢
w
;
(
a
-
1
)
wherein:
Nuptake is the aboveground nitrogen uptake of the wheat, in kg/ha;
Ngrain is a wheat grain nitrogen uptake, in kg/ha;
and
Nstraw is a wheat straw nitrogen uptake, in kg/ha;
N
uptake
=
Y
grain
*
X
grain
+
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
X
s
⁢
t
⁢
r
⁢
a
⁢
w
;
(
a
-
2
)
wherein:
Nuptake is the aboveground nitrogen uptake of the wheat, in kg/ha;
Ygrain is the wheat grain yield, in kg/ha;
Y straw is wheat straw biomass, in kg/ha;
Xgrain is a wheat grain nitrogen content, in mg/kg;
and
Xstraw is a wheat straw nitrogen content, in mg/kg;
(4) calculating a recommended wheat nitrogen fertilizer application rate for the target field according to formula (b):
N
=
N
uptake
+
N
balance
;
(
b
)
wherein, N represents the recommended wheat nitrogen fertilizer application rate, in kg/ha;
Nuptake represents the aboveground nitrogen uptake of the wheat, in kg/ha;
and Nbalance represents the nitrogen balance benchmark, in kg/ha;
wherein the wheat straw biomass is calculated according to formula (c):
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
g
⁢
r
⁢
a
⁢
i
⁢
n
*
a
;
(
c
)
wherein Ystraw is the wheat straw biomass, in kg/ha;
Ygrain is the wheat grain yield, in kg/ha;
and a represents a conversion coefficient between the wheat grain yield and the wheat straw biomass, wherein conversion coefficients for different wheat varieties are shown in a table below;
when no measured value is available for the wheat grain nitrogen uptake, the wheat grain nitrogen uptake is calculated according to formula (d):
N
grain
=
Y
grain
*
b
*
0.001
(
d
)
wherein Ngrain is the wheat grain nitrogen uptake, in kg/ha;
Ygrain is the wheat grain yield, in kg/ha;
and b represents a conversion coefficient between the wheat grain yield and the wheat grain nitrogen uptake, wherein conversion coefficients for different wheat varieties are shown in the table below;
when no measured value is available for the wheat straw nitrogen uptake, the wheat straw nitrogen uptake is calculated according to formula (e):
N
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
c
*
0.001
;
(
e
)
wherein Nstraw is the wheat straw nitrogen uptake, in kg/ha;
Y straw is the wheat straw biomass, in kg/ha;
and c represents a conversion coefficient between the wheat straw biomass and the wheat straw nitrogen uptake, wherein conversion coefficients for different wheat varieties are shown in the table below:
Conversion
Wheat-northern
Wheat-southern
coefficient
planting region
planting region
a
1.20
1.18
b
19.8
18.9
c
5.6
5.5

311 more elements

Dependencies are inferred from the claim text.

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Abstract

A simplified rice nitrogen fertilizer dosage recommendation method based on a nitrogen balance benchmark, comprising following steps:

(1) determining a soil nitrogen supply level of a target field by any one of Method 1, Method 2, Method 3, or Method 4:
Method 1:
determining the soil nitrogen supply level of the target field according to aboveground nitrogen uptake of rice under a nitrogen omission treatment, based on different rice varieties:
Soil
Aboveground nitrogen uptake of
nitrogen
rice under nitrogen omission
supply
treatment (kilograms per hectare (kg/ha))
capacity
Single-season
Middle-season
level
rice
rice
Early rice
Late Rice
Low
<58.2
<78.3
<61.2
<65.4
Medium
58.2-89.0
78.3-109.9
61.2-96.0
65.4-100.2
High
>89.0
>109.9
>96.0
>100.2
Method 2:
determining the soil nitrogen supply level of the target field according to rice yield under the nitrogen omission treatment, based on the different rice varieties:
Soil
nitrogen
supply
Rice yield under nitrogen omission treatment (kg/ha)
capacity
Single-season
Middle-
Early
level
rice
season rice
rice
Late Rice
Low
<4631
<5451
<4167
<4441
Medium
4631-6334
5451-6860
4167-6067
4441-6459
High
>6334
>6860
>6067
>6459
Method 3:
dividing the soil nitrogen supply level of the target field according to soil organic matter content:
Soil
nitrogen
supply
Soil organic matter
Soil hydrolysable nitrogen
capacity
content (grams per
content (milligrams of nitrogen per
level
kilogram (g/kg))
kilogram (mg N/kg))
Low
<10
<100
Medium
10-30
100-180
High
>30
>180
wherein the soil nitrogen supply level uses a soil organic matter content level as a judgment basis, with soil hydrolysable nitrogen as an adjustment factor:
when the soil hydrolysable nitrogen is ≥180 milligrams per kilogram (mg/kg), the soil nitrogen supply level of the low supply capacity is adjusted to the medium supply capacity;
when the soil hydrolysable nitrogen is ≤100 mg/kg, the soil nitrogen supply level of high supply capacity is adjusted to the medium supply capacity;
Method 4:
determining the soil nitrogen supply level of the target field according to soil texture and apparent characteristics:
Soil
nitrogen supply
capacity level
Conditions to be met
Medium
Soil texture:
loam or clay;
Soil color:
gray or brown
High
Soil texture:
loam or clay;
Soil color:
black
Low
The conditions above are not met
(2) determining the nitrogen balance benchmark for the target field according to the soil nitrogen supply level of the target field determined in the step (1) and in combination with a fertilization mode, with reference to a following table:
Nitrogen balance benchmark (kg/ha)
Mechanical
Nitrogen
Conventional
Controlled-
deep
fertilizer
Soil
chemical
release
placement
application
nitrogen supply
nitrogen
nitrogen
of nitrogen
via organic
Straw
capacity level
fertilizer
fertilizer
fertilizer
sources
return
Low
88.6
78.6
71.8
86.8
82.3
Medium
63.9
53.9
47.2
62.1
57.6
High
27.9
18.0
11.2
26.1
21.6
(3) obtaining Ygrain as rice grain yield based on a target yield, and determining the aboveground nitrogen uptake of the rice for the target field according to formula (a-1) or (a-2):
N
uptake
=
N
grain
+
N
straw
;
(
a
-
1
)
wherein:
Nuptake is the aboveground nitrogen uptake of the rice, in kg/ha;
Ngrain is a rice grain nitrogen uptake, in kg/ha;
and
Nstraw is a rice straw nitrogen uptake, in kg/ha;
N
uptake
=
Y
grain
*
X
grain
+
Y
straw
*
X
straw
;
(
a
-
2
)
wherein:
Nuptake is the aboveground nitrogen uptake of the rice, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
Ystraw is rice straw biomass, in kg/ha;
Xgrain is a rice grain nitrogen content, in mg/kg;
and
Xstraw is a rice straw nitrogen content, in mg/kg;
(4) calculating a recommended rice nitrogen fertilizer application rate for the target field according to formula (b):
N
=
N
uptake
+
N
balance
;
(
b
)
wherein, N represents the recommended rice nitrogen fertilizer application rate, in kg/ha;
Nuptake represents the aboveground nitrogen uptake of the rice, in kg/ha;
and Nbalance represents the nitrogen balance benchmark, in kg/ha;
wherein when no measured value is available for the rice straw biomass, the rice straw biomass is calculated according to formula (c):
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
g
⁢
r
⁢
a
⁢
i
⁢
n
*
a
;
(
c
)
wherein Ystraw is the rice straw biomass, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
and a represents a conversion coefficient between the rice grain yield and the rice straw biomass, wherein conversion coefficients for different rice varieties are shown in a table below;
when no measured value is available for the rice grain nitrogen uptake, the rice grain nitrogen uptake is calculated according to formula (d):
N
grain
=
Y
grain
*
b
*
0.001
(
d
)
wherein Ngrain is the rice grain nitrogen uptake, in kg/ha;
Ygrain is the rice grain yield, in kg/ha;
and b represents a conversion coefficient between the rice grain yield and the rice grain nitrogen uptake, wherein conversion coefficients for different rice varieties are shown in the table below;
when no measured value is available for the rice straw nitrogen uptake, the rice straw nitrogen uptake is calculated according to formula (e):
N
s
⁢
t
⁢
r
⁢
a
⁢
w
=
Y
s
⁢
t
⁢
r
⁢
a
⁢
w
*
c
*
0.001
;
(
e
)
wherein Nstraw is the rice straw nitrogen uptake, in kg/ha;
Ystraw is the rice straw biomass, in kg/ha;
and c represents a conversion coefficient between the rice straw biomass and the rice straw nitrogen uptake, wherein conversion coefficients for different rice varieties are shown in the table below:
Conversion
Single-
Middle-
coefficient
season rice
season rice
Early rice
Late rice
a
0.90
1.00
0.88
0.94
b
9.0
11.8
11.9
11.5
c
5.5
6.5
7.8
7.5

310 more elements