Book Design : Crop water requirement.



CROP WATER REQUIREMENT
·        Crop water requirement is the water required by the plants for its survivals growth, development and to produced economic parts.
·        The requirement is applied either naturally by precipitation of artificially by irrigation.
o   Transpiration less through levees (T).
o   Evaporation loos through soil surface in copied area (E)
o   Other application losses are conveyance less, percolation loss, runoff loss, etc. (WL).
Equation of WR = T + E + WP + WL + WSL
·        The estimation of water requirement of crop are one of the basic needs of crop planning on the form and for the planning of any irrigation protect.
·        Water requirement may be defined as the quantity of water required by a crop or diversified pattern of crop in a given period if the time for its normal growths under the field conditions at a place.
·        Water requirement include the losses due to ET or CU and losses during the application of irrigation water and quantity of water required for special purpose or operation such as land preparation, transplanting, leaching etc.
Its formulated as given below:—
WR = ET or W + application loss + water for special need
·        It can also be stated based on “demand” and “Supply source” as follows
WR = IR+ ER + S
IR = irrigation requirements.
ER = effective rainfall.
S = contribution from ground water table.
·        The combined loss of evaporations and transpiration from a cropped, field is termed as evapotranspiration which is otherwise known as consumptive use and denoted as ET and this is a part of water requirement.
CU = E + T + WP
So, WR = CU + WL + WSP
·        The crop water requirement may be defined as water required matting the evapotranspiration demand of the crop and special need in case or wetland crop.
NOTES: — Crop water requirement varies from place to place, crop to crop and depend on agri-ecological variation and crop characteristics.

Feature of crop water requirement –
1.     Crop factor :—
a.     Variety
b.     Growth stage
c.      Duration
d.     Crop growing season.
2.     Soil factor :—
a.     Structure
b.     texture
c.      depth
d.     composition
3.     climate factor :—
a.     temperature
b.     sunshine
c.      relative humidity
d.     wind velocity
e.     Rainfall.
Irrigation requirement: — The field irrigation requirement of crops refers to water requirement of crops exclusives or effective rainfall and contribution of soil profile.
So, IR = WR – (ER + S)
Where,
                  IR = Irrigation requirement
                  WR = water requirement
                  ER = effective rainfall.
                        S = soil moisture.
IR depend upon :—
·        Individual crop based on area of crop.
·        Losses in form water distribution system.
·        Unit = ha/ cm= water depth/land`
Net irrigation required: — It is the actual quantity of water requires in term of depth to bring the soil to field capacity level to meet the ET demand of the crop.
            D
                        D = Net irrigation water in (CM)
                        Mfci = Fc in the layer
                        Mbi = moisture content in the layer
                        Ai = bulk density
                        Di = depth (CM)
                        N = number of soil layer.
Gross irrigation requirement:— The total quantity of water used for irrigation in termed gross irrigation requirement.
The gross water requirement can be determined for a field, for a form, for an outlet command area and for an irrigation project, depending on the needs by considering the approximate losses at various stage of crop.
                        


👉About this website

  05 Aug 2019
        Hello friends,
My name is Anis kumar. I am student of bsc agriculture punjab technical university jalandhar.
          in this page we provide the book of crop water requirement. this topic is taken from subject of water management and micro irrigation.
                       
                    Thank You.