This week, We found the MAD algorithm.
M.A.D means how much percentage soil can dry while growing crops as Management Allowed Depletion. If the crop can grown at 70% of soil moisture, then MAD is 30%.
Using M.A.D, we can get irrigation set time depending on Flow rates of sprinkler(gph), Net irrigation (%), Gross Application(%).
Net irrigation means how much percent soil can intake water depending soil texture like clay, sand, loam...etc.
Gross Application means how much percent soil can intake water given by application.
We can get Gross Application(inches) : Net irrigation(inches) / Application efficiency(%, no unit) , where application efficiency means how much percent the application can make the soil wet,for example, furrow is 70~85% and drip or micro sprayer is 80~90%.
Therefore we use micro sprayer for application efficiency.
Then, We can get Irrigation Set Time (hr)
T=(GA x A)/(1.6 x Q)
where : T = Set Time, hours
GA= Gross Application, inches
A = Area, square feet (plant spacing x row spacing)
Q = Flow Rate per plant, gallons per hour (Multiply emitter flow rate by number of emitters per plant)
1.6 – Conversion Factor