Irrigation

  1. Introduction. What is irrigation? How long have people practiced irrigation and what were the major discoveries? What are the 5 main components of irrigation systems? Give examples of different kinds of irrigation systems. How important was and is irrigation?
  2. Water physics and quantities. What are surface tension and capillarity and how do they explain soil-plant-water relationships? What is heat of vaporization? What quantities and units measure water (pressure, velocity, flow, area, and precipitation rate)? How do we use them in irrigation design? How many grams are in 1 cubic centimeter of water?
  3. Evapotranspiration. What is ET? How do we measure it? Why do plants have ET? What are the 4 drivers of ET? What are the 5 ways that water enters or exits a soil-plant system?
  4. Available water capacity and degrees of soil wetness. What are saturation, field capacity, and wilting point? What is their relationship to gravitational and available water? Role of soil particle size? Where do plant roots obtain water? How do we measure AWC? What is wilt?
  5. Irrigation scheduling and conservation. What 3 things must be measured or estimated to efficiently schedule irrigation? How well do we know them? How are rain and ET distributed from month-to-month in South Florida? What do automatic valves control? What sensors are required by Florida State Law to conserve water? What is the Biscayne aquifer? Nonpoint pollution? How do Miami-Dade outdoor water restrictions conserve irrigation? Reuse water?
  6. Irrigation parts and materials. Know the names of common irrigation parts, e.g., bushings vs. adapters, their sizes and uses, and materials, e.g., PVC vs. PE, rating such as Class vs. Schedule. What is “nominal?” What are special components such as valves, filters, and controllers? What are proper methods of irrigation construction?
  7. Pipes, flow, and friction loss. Be able to read and interpret a pressure friction loss table to design an irrigation system with suitable pipe size. How does pressure relate to flow and pipe size? What is the velocity limit method? What is “friction loss” and when is it a great problem?
  8. Sprinklers. Be able to read a sprinkler table and interpret what it tells in nozzle size, pressure, flow, arc, and radius. What is precipitation rate and when is it matched or not matched and how is that useful? How do spray sprinklers differ from rotary? What is irrigation uniformity and how is it affected by sprinkler selection and spacing? How much overlap is necessary? What is “head-to-head coverage”? What is overspray and how is it prevented?
  9. Site assessment. What must you look for before irrigation design? What is a hydrozone?
  10. Irrigation design in steps. Know the steps in irrigation design and why their logical order is site assessment and rough template > block it off and select sprinklers > layout sprinklers in rectangular blocks > cloud the zones > select pipe size > draw pipes and valves. Why must the width of each rectangular block be a whole multiple of sprinkler radius? Know accepted conventions for symbols, and what useable irrigation drawings should look like, and include “pipe hops,” valve symbols, POC, mainline, legend, scale, and other documentation.
  11. Pumps and water sources. Understand the capacity of a pump, the pump performance curve, kinds of pumps and other water sources and limitations of municipal water sources.
  12. Microirrigation. What is microirrigation or drip irrigation? What the advantages and disadvantages and unique kinds of components of microirrigation compared with overhead?