Irrigation Scheduling Objectives and Concepts Irrigation Water Management Training

According to crop needs * In amounts that can be held in the soil and be available to crops At rates consistent with the intake characteristics of the soil and the erosion hazard of the site So that water quality is maintained or improved Irrigation Water Management Applying Water:

Irrigation Scheduling A part of irrigation water management

Three Keys to Good Irrigation Good Distribution Uniformity (DU) Good Timing* Minimize Surface Runoff

DU Distribution Uniformity

DU lq Exercise 1.7 inches2.0 inches 1.8 inches2.1 inches 1.9 inches2.2 inches 2.0 inches2.3 inches Given the 8 measurements above, what is the DU lq for this irrigation?

Try to Determine what the Consultant Knows A farmer has hired a consultant to schedule irrigations on his drip tape system. The consultant tells the farmer to irrigate this week for 80 hours. What does the consultant know?

What is scheduling? The decision of when and how much water to apply to a field There are many methods available It is not always an option (but remember that not to decide is to decide.)

WILLARD " They told me that you had gone totally insane and that your methods were unsound." KURTZ " Are my methods unsound?" WILLARD " I don't see any method at all, sir."

Water Balance Approach Water used must be replaced Any guesses why this is also called the checkbook method?

Balance the soil water Know how much water the soil can store Know how much water the plant has used

How much water can the soil hold? Know the depth of the root zone Know the water holding capacity of the root zone

How much water has the crop used? Know the actual crop evapo- transpiration

When Do You Irrigate? Know the Management Allowable Depletion (MAD)