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Common Unit Conversions for Irrigation

  • Page ID
    44296
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    International System of Units (SI) and U.S. Customary System of Units (USCS)

    Length Units

    1 km (kilometer) = 0.6214 mi (miles)
    1 mi = 1.609 km
    1 km = 1,000 m (meters)
    1 mi = 5,280 ft (feet)
    1 m = 3.281 ft
    1 ft = 0.3048 m
    1 m = 100 cm (centimeters)
    1 ft = 12 in (inches)
    1 in = 2.54 cm

    Area Units

    1 ha (hectare) = 10,000 m2
    1 ha = 2.471 ac (acres)
    1 ac = 0.4047 ha
    1 ac = 43,560 ft2

    Volume Units

    1 L (liter) = 0.2642 gal (gallons)
    1 gal = 3.785 L
    1 m3 = 1,000 L
    1 m3 = 264.2 gal
    1 ft3 = 7.481 gal
    1 m3 = 35.31 ft3
    1 ft3 = 0.02832 m3
    1 ac-ft (covers 1 acre with 1 foot of water) = 1,233 m3
    1 ac-ft = 325,851 gal
    1 ac-in (acre-inch) = 27,154 gal
    1 ha-cm (hectare-centimeter) = 100 m3
    1 ac-in = 1.028 ha-cm (1 for practical purposes)
    1 bu (bushel) = 35.24 L
    1 bu = 9.309 gal

    Flow Units

    1 L/s (liter/second) = 15.85 gpm (gallons/minute)
    1 gpm = 0.06309 L/s
    1 cms (m3 /s) = 1,000 L/s
    1 cms = 35.31 cfs (ft3 /s)
    1 cfs = 448.8 gpm (450 for practical purposes)
    1 cfs = 0.02832 cms
    1 ac-in/hr = 1.008 cfs (1 for practical purposes)
    1 ac-in/hr = 452.6 gpm (450 for practical purposes)

    Weight and Mass Units

    1 t (metric ton) = 1,000 kg (kilograms)
    1 T (U.S. ton) = 2,000 lb (pounds)
    1 t = 1.102 T
    1T = 0.9072 t
    1 kg = 2.205 lb
    1 lb = 0.4536 kg

    Pressure Units

    1 atm (atmosphere) = 101.3 kPa (kilopascal)
    1 bar = 100 kPa
    1 bar = 0.9869 atm (1 for practical purposes)
    1 kPa = 0.1450 psi (pounds per square inch)
    1 psi = 6.895 kPa
    1 m (meter of water head) = 9.804 kPa
    1 ft (foot of water head) = 0.4335 psi
    1 kPa = 0.3346 ft = 0.1020 m (0.1 for practical purposes)
    1 psi = 2.307 ft = 0.7032 m (0.7 for practical purposes)

    Crop Yield Units

    Rice, cotton, alfalfa, and similar crops

    1 lb/ac (lb dry weight/ac) = 1.121 kg/ha (kg dry mass/ha)
    1 kg/ha = 0.8922 lb/ac
    1 T/ac (T dry weight/ac) = 2.242 t/ha (t dry mass/ha)
    1 t/ha = 0.4461 T/ac

    Tree fruit, grapes, vegetables, and similar crops

    1 lb/ac (lb wet weight/ac) = 1.121 kg/ha (kg wet mass/ha)
    1 T/ac (T wet weight/ac) = 2.242 t/ha (t wet mass/ha)

    Maize/corn[a]

    1 bu/ac (bushel/ac) = 0.0530 t/ha (t dry mass/ha)
    1 t/ha = 18.9 bu/ac

    Soybean[a]

    1 bu/ac = 0.0585 t/ha (t dry mass/ha)
    1 t/ha = 17.1 bu/ac

    [a] The unit of bu/ac is volume per area. The volume (bu) is calculated using the wet weight of the grain, a wet bulk density of 56 lb/bu (maize) or 60 lb/bu (soybean), and an assumed grain moisture content (wet basis) of 15.5% (maize) or 13% (soybean).

    Temperature Conversions (C to F)

    For every increase of five degrees in Celsius, Fahrenheit degrees increase by 9.
    ºC ºF
    0 32
    5 41
    10 50
    15 59
    20 68
    25 77
    30 86
    35 95
    40 104

    Temperature Conversions (F to C)

    For every 10 degree increase in Fahrenheit, Celsius increases by about 5.5 degrees.
    ºF ºC
    30 -1
    40 4
    50 10
    60 16
    70 21
    80 27
    90 32
    100 38
    110 43

    US Public Land Survey System

    Compares relative coverage of two sprinkler systems.1 square mile is divided into four quadrants of 160 acres. One quadrant is watered with an End Gun sprinkler system, and one is watered by a Swing Boom Corner system. The Swing Boom irrigates an additional 20 acres.

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