Information Technology Reference
In-Depth Information
where Δ
is the slope of the saturated vapor pressure-temperature curve (kPa°C
-1
);
R
n
is
the net radiation from the crop canopy surface
(MJm
-2
h
-1
);
G
is the soil heat flux
(MJm
-2
h
-1
);
γ
is the hygrometer constant;
T
is the daily average temperature (°C)
;
u
2
is
the wind speed at 2 m height;
e
s
is the saturation vapor pressure (kPa);
e
a
is the actual
vapor pressure; the soil heat flux
G
is calculated from the following formula:
G
=0.1*
R
n
. (11)
The potential land productivity can be obtained from the potential climate produc-
tivity (
Y
w
) and the validity coefficient for soil:
()
Yf
=
s
⋅
Y
.
(12)
L
w
Twelve factors that influence soil properties are selected and their weighting coef-
ficients (
W
i
) are determined by establishing a comparison matrix based on their relative
importance to soil effectiveness, soil properties and soil nutrients.The ESLP calculates
the soil effectiveness coefficients using the following formula:
∑
(13)
fs
()
=
AW
⋅
.
i
i
i
The ESLP uses the Cobb-Douglas function to estimate land productivity influenced
by fundamental inputs and conventional production inputs as follows:
Y
=
AK
1
α
K
2
β
YL
γ
. (14)
where
Y
is the land productivity;
A
is the scaling parameter of the Cobb-Douglas
function;
K
1
is the fundamental input for improving land conditions;
K
2
is the routine
productive input for specific production processes;
YL
γ
is the potential land productiv-
ity;
α
,
β
and
γ
meet the following conditions:
α
+
β
+
γ
=1. (15)
The total investment is allocated between the fundamental inputs and conventional
production inputs based on the profit maximization principle. Assuming that the total
investment amount is
M
, then
M
=
K
1
P
1
+
K
2
P
2
. (16)
where
P
1
and
P
2
are the prices of fundamental inputs and productive inputs, respec-
tively. So the allocation of the total investment between the fundamental inputs and
productive inputs satisfies the optimum condition:
MAX
W
=
AK
1
α
K
2
β
YL
γ
P
-
K
1
P
1
-
K
2
P
2
. (17)
where
W
is the production profit, and
P
is the product price. The optimum investment
program is found by solving the equations above, so that:
1
1
−
β
β
⎛ ⎞
1
αβ
+−
1
⎛ ⎞
P
⎛ ⎞
P
αβ
+−
1
(18)
αβ
+−
1
K
=
1
2
,
⎜ ⎟
⎜ ⎟
⎜ ⎟
1
γ
Y
α
β
⎝ ⎠
⎝ ⎠
⎝ ⎠
L
1
1
−
α
α
⎛ ⎞
1
αβ
+−
1
⎛ ⎞
P
⎛ ⎞
P
(19)
αβ
+−
1
αβ
+−
1
K
.
=
1
2
⎜ ⎟
⎜ ⎟
⎜ ⎟
2
Y
γ
⎝ ⎠
α
β
⎝ ⎠
⎝ ⎠
L
Search WWH ::
Custom Search