Irrigation Tables | Irrigation Home Study Course

A summary of the tables from all the chapters plus a few more.

Chapter 3

Table 3.1. Available water capacity based on soil texture
Textural Classes	Available water capacity in inches per foot of depth
Coarse sand	0.25 - 0.75
Find sand	0.75 - 1.00
Loam sand	1.10 - 1.20
Sandy loam	1.25 - 1.40
Fine sandy loam	1.50 - 2.00
Silt loam	2.00 - 2.50
Silty clay loam	1.80 - 2.00
Silty clay	1.50 - 1.70
Clay	1.20 - 1.50

Table 3.2. Range of infiltration rates for several soil textures.
Soil texture	Basic infiltration rate, in/hr
Fine sand	0.50 - 0.75
Sandy loam	0.35 - 0.50
Silt loam	0.25 - 0.40
Clay	0.10 - 0.20

Chapter 4

Table 4.1. Maximum crop rooting depth for irrigation water management.
	2.0 feet	3.0 feet	3.5 feet	4.0 feet
Crop	Dry beans Potatoes	Corn Grain sorghum Soybeans Sugar beets Pasture	Spring grain	Alfalfa Winter grain

Chapter 6

Table 6.1. Grain yields, water use, and irrigation for continuous corn grown in North Platte, NE, 1085-87.
	Dryland	Limited Irrigation	Full Irrigation
Irrigation(In)	0.0	5.7	15.6
Rainfall (In)	6.5	6.5	6.5
Stored soil water used (In)	7.9	6.4	0.3
ET (In)	14.4	18.6	22.4
Grain yield (bu/ac)	59.0	135.0	178.0

Table 6.2. Crop coefficients to be used with alfalfa reference crop ET to estimate ET for some Nebraska crops.
*Stage*	*Corn*	*K_c*	*Soybean*	*K_c*	*Wheat*	*K_c*
1	2 leaves	0.10	Emergence	0.10	Emergence	0.10
2	4 leaves	0.18	Cotyledon	0.10	Visiblecrown	0.50
3	6 leaves	0.35	First node	0.20	Leaf elongation	0.90
4	8 leaves	0.51	Second node	0.40	Jointing	1.00
5	10 leaves	0.69	Third node	0.60	Boot	1.00
6	12 leaves	0.88	Beginning bloom	0.90	Heading	1.00
7	14 leaves	1.00	Full bloom	1.00	Flowering	1.00
8	16 leaves	1.00	Beginning pod	1.00	Grain fill	1.00
9	Silking	1.00	Full pod	1.00	Stiff dough	0.90
10	Blister	1.00	Beginning seed	1.00	Ripening	0.50
11	Dough	1.00	Full seed	1.00	Mature	0.10
12	Beginning dent	1.00	Beginning maturity	0.80
13	Full dent	0.88	Full maturity	0.10
14	Black layer	0.50
15	Full maturity	0.10

*Stage*	*Potato*	*K_c*	*Drybean*	*K_c*	*Sugar Beet*	*K_c*
1	Emergence	0.10	Emergence	0.10	Emergence	0.10
2	Early vegetative	0.13	Cotyledon	0.10	Cover 20%	0.14
3	Vegetative	0.30	4-7th trifoliate	0.48	Cover 30%	0.21
4	Blossom	0.53	Beginning flowering	0.81	Cover 50%	0.34
5	Early tuber	0.76	Flowering	1.00	Cover 70%	0.48
6	Tuberization	0.91	Begommomg [pd fill	1.00	Cover 80%	0.60
7	Tuber bulk	0.85	Pod fill	0.83	Cover 90 %	0.73
8	Tuber bulk	0.6	Beginning maturity	0.59	Full cover	0.83
9	Early Senescence	0.30	50% pods	0.30	Max LAI	0.91
10	Senescence	0.10	Buckskin	0.20	Root stage	0.91
11	Mature	0.10	Mature	0.10	After frost	0.05

Chapter 8

Table 8.1. Potential sources of water loss during an irrigation event for surface and sprinkler irrigation systems.
Sources of water losses	Surface irrigation	Sprinkler irrigation
Distribution system	Yes	Yes
Air evaoration	No	Yes
Plant interception	No	Yes
Soil evaporation	Yes	Yes
Deep percolation	Yes	Yes
Runoff	Yes	Yes

Table 8.2. Percent irrigation water losses for different irrigation systems.
Type of irrigation system	Distribution system	Air evaporation	Soil evaporation	Canopy evaporation	Deep percolation	Surface runoff	Overall efficiency
Furrow irrigation:
Every row	1-5	<1.0	1-5	0.0	10-20	10-35	40-75
W/Surge valve	1-5	<1.0	1-5	0.0	5-15	5-15	60-85
W/Reuse	1-5	1-2	1-5	0.0	10-20	0	55-90
Siphon tube	5-10	1-2	1-5	0.0	15-25	15-25	40-75
Alternate row	1-5	< 0.5	1-3	0,0	5-15	10-20	60-85
Sprinkler Irrigation:
Handmove	<1.0	3-5	1-5	10-15	5-10	0-5	60-80
Solid set	<1.0	3-5	1-5	10-15	0-10	0-5	60-85
Traveler	<1.0	1-3	1-5	1-5	0-5	5-10	55-75
High pressure impact	<0.5	1-3	0-1	1-5	0-5	0-5	70-80
Low pressure impact	<0.5	1-3	0-1	1-3	0-5	0-10	75-85
Low pressure spray	<0.5	1-3	0-1	1-3	0-5	0-20	70-90
Low pressure bubble	<0.5	0.0	0-0.5	0.0	0-5	20-40	60-95
Drip irrigation	<0.5	0.0	0.0	0.0	5-30	0.0	70-95

Chapter 9

Table 9.1. Available water and minimum water balance to maintain maximum ET rates for soil textural classes.
	Minimum water balance¹ -------% of available water-------
Soil textural classification	100% Available water	75% Potatoes	60% Alfalfa, dry beans, cool season pasture, or small grains	50% Corn, warm season pasture, sorghum, soybeans, or sugar beets
	-------------------------In/ft²---------------------------
Fine sands		1.0	0.8	0.6	0.5
Loamy sand		1.1	0.8	0.7	0.6
Sandy loam		1.4	1.0	0.8	0.7
Silty clay or Clay		1.6	1.2	1.0	0.8
Fine sandy loam, Silty clam loam, or Clay loam		1.8	1.4	1.1	0.9
Sandy clay loam		2.0	1.5	1.2	1.0
Loam, Very fine sandy loam, or Silt loam topsoil	Silty clay loam or silty clay subsoil	2.0	1.5	1.2	1.0
Loam, Very find sandy loam, or Silt loam topsoil	Medium textured subsoil	2.5	1.9	1.5	1.3
¹Lower minimum water balances may be desirable during some crop growth stages in water short areas or if pumping cost are high. A minimum water balance of 40% is generally recommended for late season water management.²Inches of water per foot of active root zone.

Table 9.2. Suggested root depth for irrigation scheduling versus stage of growth for various crops
Root Depth (ft.)	Corn	Soyeans	Grain Sorghum	Spring Grains	Winter Wheat	Alfalfa	Sugar Beets	Dry Beans	Established Pasture	Potatoes
1.0	Vegetative	Vegetative	Vegetative					Vegetative		Seeding
1.5								Initial flower pod set		Bloom
2.0	12 leaf	Early bloom			Fall growth		June 1	Beginning pod fill	Cool season
2.5	16 leaf	Full bloom	Flag leaf	Joint	Spring growth		July 1	Full seed fill		Maturity
3.0	Silking	Pod elongation	Boot	Boot	Joint		July 15		Warm season
3.5	Blister		Bloom	Flowering	Boot		Aug. 1
4.0	Beginning dent	Full seed fill	Dough	Dough	Dough	Estab-lished stand	Sept. 1
¹Restrictive layers (hardpans, compacted layers, or layers of coarse material) can reduce the rooting depth.

Table 9.3. Approximate water use rates by stage of growth for various crops
Water Use Rate In/Day	Corn	Grain Sorghum	Soybeans	Alfalfa¹	Dry beans	Sugar Beets	Winter wheat	Potatoes²
0.18						June 15	Spring growth	May 20
0.20
0.22			Full bloom			July 1		June 5
0.24	12 leaf				Rapid vegetative growth		Joint
0.26		Flag leaf	Begin pod					July 5
0.28	Early tassel	Boot		June 15
0.30	Silking	Half bloom	Full Pod	July 1	Flowering and pod development	July 15	Boot
0.28				August 1
0.26	Blister	Soft dough				August 1
0.24	Milk		Seed Fill	August 15				August 15
0.22				Sept. 1			Dough
0.20	Begin dent
0.18	Full dent	Hard dough			Pod fill and maturation			Sept. 10
¹Alfalfa water use rates should be multiplied by 0.50 during the first ten days following cutting and by 0.75 for the 10^th to 20^th day following cutting.²Taken from: Wright, J.L., J.C. Sturk. In Press. Irrigation of Potatoes. In American Society of Agronomy Monograph: “Irrigation of Agricultural Crops” Section VII, Chapter 29.

Chapter 11

Table 11.1. Target cutoff ratio based on soil and system combinations.
	Sandy Soils	Loamy Soils	Clayey Soils
Without reuse	0.50	0.70	0.90
With reuse	0.20	0.40	0.50

Table 11.2. Example showing how the set-time and cutoff ratio are used to improve the performance of a furrow irrigated set.
Parameter	Calculation Method	Our Example
Target cutoff ration	Table 11.1	0.50
New advance time	Target cutoff ratio x new set time	0.50 x 12 hrs = 6.0 hrs
Advance time ration	New advance time original advance time	6.0 hrs / 15 hrs = 0.40
Furrow ratio	Figure 11.2	0.60
New number of gates	Original number of gates x furrow ration	80 x 0.60 = 48 gates
New stream size	Equation 11.1	760 / 48 = 15.6 gpm
New gross application	Equation 11.2	(1155 x 15.6 x 12) / (2600 x 30) = 2.8 in

Table 11.3. Recommended cutoff ratios for blocked-end furrow irrigation systems.
General Slope Description	Slope Percent	Clayey Soils	Loamy Soils	Sandy Soils
Low	0.1	0.95	0.85	0.70
Moderate	0.5	0.90	0.80	0.65
Steep	1.0	0.85	0.75	0.60

Table 11.4. Corn yield (bushels/acre) on various soils when irrigating every furrow vs. every-other furrow using a 12-hour set time.
Soil	Every furrow	Every-other furrow
Albaton clay loam	157	154
Luton silty clay loam	152	159
Crete silty clay loam	153	156
Holdrege silt loam	179	177
Sarpy sandy loam	140	143
Ortello sandy loam	118	119
One sandy loam	114	107

Table 11.5. Surge irrigation on-time factors.
Advance cycle no.	Fraction of field	On-time factor
On-time factors using four surge cycles.
1	.25	1.0
2	.50	1.9
3	.75	2.4
4	1.00	2.9
Post advance or cutback	0.8 - 1.6

On-time factors using five surge cycles.
1	.20	1.0
2	.40	1.9
3	.60	2.4
4	.80	2.9
5	1.00	3.3

Post advance or cutback	1.2 - 2.3

On-time factors using six surge cycles.
1	.17	1.0
2	.34	1.9
3	.51	2.4
4	.68	2.9
5	.85	3.3
6	1.00	3.7
Post advance or cutback	1.5 - 3.0

Chapter 12

Table 12.1 Minimum net system capacities for the major soil texture classifications and regions of Nebraska.^*
Soil Texture	Available soil water capacity (inches/foot)	Region 1 (gpm/acre)**	Region 2 (gpm/acre)**
Loam, silt loam very fine sandy loam w/silt loam subsoil	2.5	3.85	4.62
Sandy clay loam loam, silt loam very fine sandy loam, w/silty clay subsoil	2.0	4.13	4.89
Silty clay loam Clay loam Fine sandy loam	2.0	4.24	5.07
Silty clay	1.6	4.36	5.13
Clay Sandy loam	1.4	4.48	5.19
Loamy sand	1.1	4.83	5.42
Find sand	1.0	4.95	5.89
Peak evapotranspiration^***		5.65	6.60
^Taken from Transactions of the American Society of Agricultural Engineers, 27(2):419-428. Net system capacity required to replace average peak water use rate nine out of ten years. Values must be multiplied by the acres irrigated and adjusted for irrigation efficiency to estimate gross pumping rates.^**Estimated net system capacity to replace average crop water use 100 percent of the time.

Table 12.2. Power interruption and repair and maintenance multiplication factors for different system down times.
	Shutdown time (hours) per week
Hours	0	12	24	36	48	60
Multiplier	1.00	1.08	1.17	1.27	1.4	1.55

Table 12.3 Summary of soil mapping unit information for a quarter section of land in Pierce Counth, NE and presented in Figure 12.4.
Soil mapping unit	Field slope	Intake family number (%)	Water holding capacity (inches/foot)	Field area (acres)
Co	0 to 1	0.3	0.20 to 0.23	42
He	0 to 1	1.0	0.21 to 0.23	24
CsC2	1 to 7	1.0	0.20 to 0.23	11
HhC	1 to 7	1.0	0.21 to 0.23	5
MoC	1 to 7	0.5	0..19 to 0.22	37
CsD2	7 to 11	1.0	0.20 to 0.23	28
MpD	7 to 11	1.0	0.20 to 0.23	2
CsE2	11 to 17	1.0	0.20 to 0.23	11

Chapter 13

Table 13.1. Nebraska Performance Criteria for pumping plants.
Energy Source	hp.h^a	whp.h^b Unit of Energy	Energy Unit of Energy^c
Diesel	16.66	12.5	gallon
Gasoline	11.5	8.66	gallon
Propane	9.20	6.89	gallon
Natural gas^d	82.20	61.7	1000 ft³ (MCF)
Natural gas^e	8.89	6.67	Therm
Electricity^f	1.18	0.885	kW.h
^ahp.h (horsepower hours) is the work accomplished by the power unit with drive losses considered.^bwhp.h (water horsepower hours) is the work accomplished by the pumping plant (power unit and pump) at the Nebraska Performance Criteria.^cBased on 75% pump efficiency^dAssumes an energy content of 925 BTU / cubic foot^eSome natural gas suppliers price their gas by the therm. A therm = 100,000 BTU.^fAssumes 88 percent electric motor efficiency

Table 13.2. Nebraska Pumping Plant Test Results - 1980. 1981, 1982
	Performance Rating, % of the NPPPC
	100+	90-100	75-89	50-74	49 or less	Total
Number of Tests	27	42	40	59	12	180
% of Total	15%	23%	22%	33%	7%	100%
Average Performance Rating — 77%

Table 13.3 Equivalent Price Factors for Irrigation Energy Sources
	Equivalent Price Factors
	Diesel	Natural Gas	LP Gas	Electricity	Gasoline
Diesel	1.0	4.936	0.551	0.071	0.693
Natural Gas	0.203	1.0	0.112	0.014	0.140
LP Gas	1.814	8.955	1.0	0.128	1.257
Electricity	14.124	69.718	7.785	1.0	9.785
Gasoline	1.443	7.125	0.796	0.102	1.0

Additional Useful Tables

Root depth versus stage of growth*
Assumed root depth (ft)	Corn (3)^**	Grain Sorghum (3)**	Soybeans (3)**	Alfalfa (4)**	Dry beans (2.5)**	Beets (3)**	Winter Wheat (4)**
1.0	Vegetative	Vegetative	Vegetative		Vegetative
1.5					Initial flowering pod set
2.0	12 leaf		early bloom			June 1	Fall Growth
2.5	Early tassel 16 leaf	Flag leaf	Full bloom		Beginning pod	July 1 fill
3.0	Silking	Boot	Pod elongation		Full seed fill***		Spring growth
3.5	Blister			***		July 15
4.0	Beginning dent***	Dough***	Full seed fill***			Aug 1***	Joint***
5.0							Boot
6.0				Established stand			Dough

*Restrictive layers (hardpans, compacted layers, or layers of course material) can reduce the rooting depth. **Maximum crot root depth for irrigation management (assuming no restrictive layers). ***Use this depth for the last irrigation (assuming no restrictive layers). See NebGuide G82-602 for further information regarding the date for the last irrigation.

Approximate water use rates by stage of growth for various crops.
Water Use Rate (in/day)	Corn	Sorghum	Soybeans	Dry Beans	Sugarbeets	Winter Wheat	Alfalfa*
0.18					June 15	Spring growth
0.20			Full bloom		July 1
0.24	12 leaf			Rapid vegetative growth		Joint
0.26		Flag leaf	Begin pod
0.28	Early tassel	Boot					June 15
0.30	Silking	Half bloom	Full pod	Flowering and pod development	July 15	Boot	July 1
							Aug 1
0.28
0..26	Blister kernel	Soft Dough			Aug 1		Aug 15
0.24	Milk		Bean fill				Sept 1
0.22						Dough
0.20	Begin Dent
0.18	Full dent	Hard dough		Pod fill and maturation

*Alfalfa water use rates should be multiplied by 0.50 during the first ten days following cutting and by 0.75 from the 10th to the 20th following cutting.

Available water capacity and minimum water balance for soil textural classes.
Soil textural classification	AWC	Minimum water balance
	----------------inches/ft-----------------
Fine sands	1.0	0.5
Loamy sand	1.1	0.6
Sandy loam	1.4	0.7
Silty clay or clay	1.6	0.8
Fine sandy loam, silty clay loam, or clay loam	1.8	0.9
Sandy clay loam	2.0	1.0
Loam, very fine sandy loam, silt loam topsoil w/silty clay loam, or silty clay subsoil	2.0	1.0
Loam, very fine sandy loam, or silt loam topsoil w/medium subsoil	2.5	1.3

*Available water capacity **Inches of water per foot or active root zone

Efficiency of Irrigation Systems
System type	Efficiency factor
Conventional gated pipe	.50
Gated pipe w/reuse	.70
Alternate furrow	.60
Alternate furrow w/reuse	.75
Surge flow, well managed	.80
Pivot, linear move	.85 - .90

**Table of Equivalents**
Volume
1 gallon =	8.33 pounds
1 cubic foot =	7.48 gallons
1 acre-inch =	27,154 gallons
1 acre-foot =	325,851 gallons
1 acre-foot =	43,560 cubic feet
Flow
1 cubic foot per second =	450 gallons per minute
1 acre-inch per hour =	450 gallons per minute
1 cubic foot per second for 1 hour =	1 acre-inch
450 gallons per minute for 1 hour =	1 acre-inch

Volume of water applied for various flow rates and time periods
Flow rate (gpm)	Volume applied
1 Hour - shift entire row right (ac-in)	12 Hour (ac-in)	1 Day (ac-in)
100	0.22	2.65	5.30
200	0.44	5.31	10.60
300	0.66	7.96	15.90
400	0.88	10.60	21.20
500	1.11	13.30	26.50
600	1.33	15.90	31.90
700	1.55	18.60	37.20
800	1.77	21.20	42.50
900	1.99	23.90	47.80
1000	2.21	26.50	53.10
1100	2.43	29.20	58.40
1200	2.65	31.80	63.70
1300	2.88	34.50	69.00
1400	3.10	37.20	74.30
1500	3.22	39.80	79.60
2000	4.42	53.10	106.00

Acres irrigated with a center pivot
*System length (feet)*	*No end gun or sprinkler*	*End gun on at all times*	*End gun only in corners*
660	31	40	36
785	44	56	50
915	60	74	67
1040	78	94	86
1170	98	116	107
1300	121	140	131
1425	146	167	157
1550	173	196	185
1680	200	227	214
1810	235	262	249
1935	269	298	284

Acres in an irrigation set
Row length (Feet)	Number of rows per set (30 inch rows)
10--shift entire row right	20	30	40	50	70	80	90	100
660	0.4	0.8	1.1	1.5	1.9	2.7	3.0	3.4	3.8
825	0.5	0.9	1.4	1.9	2.4	3.3	3.8	4.3	4.7
990	0.6	1.1	1.7	2.3	2.8	4.0	4.5	5.1	5.7
1155	0.7	1.3	2.0	2.7	3.3	4.6	5.3	6.0	6.6
1320	0.8	1.5	2.3	3.0	3.8	5.3	6.1	6.8	7.6
1485	0.9	1.7	2.6	3.4	4.3	6.0	6.8	7.7	8.5
1650	0.9	1.9	2.8	3.8	4.7	6.6	7.6	8.5	9.5
1815	1.1	2.1	3.1	4.2	5.2	7.3	8.3	9.4	10.4
1980	1.1	2.3	3.4	4.5	5.7	8.0	9.1	10.2	11.4
2145	1.2	2.5	3.7	4.9	6.2	8.6	9.8	11.1	12.3
2310	1.3	2.7	4.0	5.3	6.6	9.3	10.6	11.9	13.3
2475	1.4	2.8	4.3	5.7	7.1	9.9	11.4	12.8	14.2
2640	1.5	3.0	4.5	6.1	7.6	10.6	12.1	13.6	15.2

Additional Useful Tables

Root depth versus stage of growth*
Assumed root depth (ft)	Corn (3)^**	Grain Sorghum (3)**	Soybeans (3)**	Alfalfa (4)**	Dry beans (2.5)**	Beets (3)**	Winter Wheat (4)**
1.0	Vegetative	Vegetative	Vegetative		Vegetative
1.5					Initial flowering pod set
2.0	12 leaf		early bloom			June 1	Fall Growth
2.5	Early tassel 16 leaf	Flag leaf	Full bloom		Beginning pod	July 1 fill
3.0	Silking	Boot	Pod elongation		Full seed fill***		Spring growth
3.5	Blister			***		July 15
4.0	Beginning dent***	Dough***	Full seed fill***			Aug 1***	Joint***
5.0							Boot
6.0				Established stand			Dough

*Restrictive layers (hardpans, compacted layers, or layers of course material) can reduce the rooting depth. **Maximum crot root depth for irrigation management (assuming no restrictive layers). ***Use this depth for the last irrigation (assuming no restrictive layers). See NebGuide G82-602 for further information regarding the date for the last irrigation.

Approximate water use rates by stage of growth for various crops.
Water Use Rate (in/day)	Corn	Sorghum	Soybeans	Dry Beans	Sugarbeets	Winter Wheat	Alfalfa*
0.18					June 15	Spring growth
0.20			Full bloom		July 1
0.24	12 leaf			Rapid vegetative growth		Joint
0.26		Flag leaf	Begin pod
0.28	Early tassel	Boot					June 15
0.30	Silking	Half bloom	Full pod	Flowering and pod development	July 15	Boot	July 1
							Aug 1
0.28
0..26	Blister kernel	Soft Dough			Aug 1		Aug 15
0.24	Milk		Bean fill				Sept 1
0.22						Dough
0.20	Begin Dent
0.18	Full dent	Hard dough		Pod fill and maturation

*Alfalfa water use rates should be multiplied by 0.50 during the first ten days following cutting and by 0.75 from the 10th to the 20th following cutting.

Available water capacity and minimum water balance for soil textural classes.
Soil textural classification	AWC	Minimum water balance
	----------------inches/ft-----------------
Fine sands	1.0	0.5
Loamy sand	1.1	0.6
Sandy loam	1.4	0.7
Silty clay or clay	1.6	0.8
Fine sandy loam, silty clay loam, or clay loam	1.8	0.9
Sandy clay loam	2.0	1.0
Loam, very fine sandy loam, silt loam topsoil w/silty clay loam, or silty clay subsoil	2.0	1.0
Loam, very fine sandy loam, or silt loam topsoil w/medium subsoil	2.5	1.3

*Available water capacity **Inches of water per foot or active root zone

Efficiency of Irrigation Systems
System type	Efficiency factor
Conventional gated pipe	.50
Gated pipe w/reuse	.70
Alternate furrow	.60
Alternate furrow w/reuse	.75
Surge flow, well managed	.80
Pivot, linear move	.85 - .90

**Table of Equivalents**
Volume
1 gallon =	8.33 pounds
1 cubic foot =	7.48 gallons
1 acre-inch =	27,154 gallons
1 acre-foot =	325,851 gallons
1 acre-foot =	43,560 cubic feet
Flow
1 cubic foot per second =	450 gallons per minute
1 acre-inch per hour =	450 gallons per minute
1 cubic foot per second for 1 hour =	1 acre-inch
450 gallons per minute for 1 hour =	1 acre-inch

Volume of water applied for various flow rates and time periods
Flow rate (gpm)	Volume applied
1 Hour (ac-in)	12 Hour (ac-in)	1 Day (ac-in)
100	0.22	2.65	5.30
200	0.44	5.31	10.60
300	0.66	7.96	15.90
400	0.88	10.60	21.20
500	1.11	13.30	26.50
600	1.33	15.90	31.90
700	1.55	18.60	37.20
800	1.77	21.20	42.50
900	1.99	23.90	47.80
1000	2.21	26.50	53.10
1100	2.43	29.20	58.40
1200	2.65	31.80	63.70
1300	2.88	34.50	69.00
1400	3.10	37.20	74.30
1500	3.22	39.80	79.60
2000	4.42	53.10	106.00

Acres irrigated with a center pivot
System length (feet)	No end gun or sprinkler	End gun on at all times	End gun only in corners
660	31	40	36
785	44	56	50
915	60	74	67
1040	78	94	86
1170	98	116	107
1300	121	140	131
1425	146	167	157
1550	173	196	185
1680	200	227	214
1810	235	262	249
1935	269	298	284

Acres in an irrigation set
Row length (Feet)	Number of rows per set (30 inch rows)
10	20	30	40	50	70	80	90	100
660	0.4	0.8	1.1	1.5	1.9	2.7	3.0	3.4	3.8
825	0.5	0.9	1.4	1.9	2.4	3.3	3.8	4.3	4.7
990	0.6	1.1	1.7	2.3	2.8	4.0	4.5	5.1	5.7
1155	0.7	1.3	2.0	2.7	3.3	4.6	5.3	6.0	6.6
1320	0.8	1.5	2.3	3.0	3.8	5.3	6.1	6.8	7.6
1485	0.9	1.7	2.6	3.4	4.3	6.0	6.8	7.7	8.5
1650	0.9	1.9	2.8	3.8	4.7	6.6	7.6	8.5	9.5
1815	1.1	2.1	3.1	4.2	5.2	7.3	8.3	9.4	10.4
1980	1.1	2.3	3.4	4.5	5.7	8.0	9.1	10.2	11.4
2145	1.2	2.5	3.7	4.9	6.2	8.6	9.8	11.1	12.3
2310	1.3	2.7	4.0	5.3	6.6	9.3	10.6	11.9	13.3
2475	1.4	2.8	4.3	5.7	7.1	9.9	11.4	12.8	14.2
2640	1.5	3.0	4.5	6.1	7.6	10.6	12.1	13.6	15.2