July 1985
Western Journal of Agricultural Economics
TABLE 1. Imperial Valley Model: Selected Resource Constraints and Requirements.
|
Acreage Constraints |
Proportional Constraintsb |
Water | |||||
|
800 MgZIiter |
1,100 MgZIiter | ||||||
|
Mini- |
Maxi- |
Mini- |
Maxi- | ||||
|
Minimum |
Maximum | ||||||
|
Land Constraints | |||||||
|
Crops |
580,000 | ||||||
|
Well drained land |
140,000 | ||||||
|
Poorly drained land |
310,000 | ||||||
|
Doublecropped, well | |||||||
|
drained land |
100,000 | ||||||
|
Doublecropped, poorly | |||||||
|
drained land |
30,000 | ||||||
|
Water Constraint | |||||||
|
(Acre-feet) |
2,566,000 | ||||||
|
Crop Constraints | |||||||
|
Alfalfaa |
150,000 |
30 |
40 |
30 |
50 |
6.3 | |
|
Cotton |
60,000 |
10 |
10 |
5.4 | |||
|
Sudangrass |
22,000 |
35,000 |
30 |
40 |
30 |
40 |
3.2 |
|
Sugar Beets |
35,000 |
50,000 |
3 |
10 |
3 |
10 |
7.1 |
|
Wheat |
100,000 |
10 |
30 |
10 |
30 |
2.7 | |
|
Asparagus |
2,500 |
4,000 |
0 |
0 |
5.8 | ||
|
Broccoli |
1,000 |
4,000 |
65 |
75 |
65 |
90 |
4.7 |
|
Spring Canteloupe |
4,500 |
7,500 |
60 |
80 |
60 |
90 |
4.1 |
|
Fall Canteloupe |
4,500 |
7,500 |
60 |
80 |
60 |
90 |
2.5 |
|
Carrots |
6,000 |
8,000 |
100 |
100 |
5.8 | ||
|
Lettuce |
37,000 |
45,000 |
65 |
75 |
65 |
90 |
3.8 |
|
Onions |
4,500 |
7,500 |
100 |
100 |
4.7 | ||
|
Tomatoes |
1,500 |
3,500 |
85 |
90 |
7.4 | ||
|
Watermelon |
1,000 |
5,000 |
60 |
80 |
60 |
90 |
3.4 |
a Alfalfa establishment requirement—1 acre establishment for every 3 acres alfalfa.
b Percentage of total crop acreage grown on well drained land.
° Acre-feet per acre of water applied to field.
were adjusted to make implied aggregate
water use match historical deliveries.
Agricultural benefit estimates. Benefits
are defined in terms of annual “damages-
avoided” per mg∕liter reduction in salt
concentration. Damages are measured by
comparison of annual net returns to land,
water, management and risk at various sa-
linity levels.
The results from the 800 and 1,100 mg∕
liter models show that the increase of 300
mg∕liter caused returns to land, manage-
ment, and risk to decline by $113.4 mil-
lion, equivalent to an average of $46,300
per mg∕liter. By way of comparison, the
Moore et al. damage estimates (converted
6
to 1982 dollars) amount to $34,380 per
mg∕liter between 480 and 960 mg∕liter
and $52,870 per mg∕liter from 960 to
1,280 mg∕liter. USBR (1980:8) estimated
average salinity damage in the 800 to
1,110 mg∕liter to be $15,600 in 1982 dol-
lars. (The large difference here appears to
stem from the use in our model of pro-
portional constraints to limit cropping
pattern adjustments and to the fact that
USBR did not extrapolate higher yields on
the best soil from the average valley wide
yield, which led to smaller absolute yield
decrements.)
The $46,300 per mg∕liter damages in
the Imperial Valley can be extended to