Applied Method for Drip Irrigation Scheduling

Two methods for drip irrigation scheduling for cash crop cultivation in greenhouses and small-scale farmlands are presented in this paper. Method 1 is installing a tensiometer at the depth of 20cm immediately under an emitter. Irrigation starts when soil water potential is out of the desired range while the irrigation quantity per irrigation times is the same during crop growing seasons or the irrigation quantity per irrigation times for every growing stage of crops are the same. For most crops, the desired range of soil water potential is set as -25 to -35kPa and the irrigation quantity is set as 5mm per irrigation times will produce good yields. Method 2 is installing a 20cm standard evaporating dish on the top of crops. When the irrigation frequency is determined, irrigation quantity of next irrigation cycle can be determined to be equal to the value of pen evaporation of this cycle multiple correlation coefficient. For most crop in greenhouses, good yields will be get as long as the coefficient is set to 1,and the irrigation frequency is set as each one day one times, each two days one times or each three days one times.