1. Irrigation Chapter #7

2. What is irrigation? ä the controlled application of water ä xerophytes, mesophytes, hydrophytes

3. What is transpiration? ä plants give off water in the form of a gas ä 99% of water is transpired

4. What is Transpiration Ratio? ä pounds of water transpired for each pound of dry matter produced (table page 74)

5. What is water use efficiency? ä pounds of dry matter produced per inch of water used

6. What is an inch of rain mean? ä enough water to cover an acre with 1" of water ä not all water is used by the plant (evaporation, runoff etc)

7. How do growing conditions affect water requirements for plants? ä high wind or temp = more water ä disease = more water ä seedling development = less water ä crop maturity = less water ä nitrogen encourages water use

8. What is climate? ä the amount of water throughout the season

9. What is the climate in Northeast Montana? ä semi-arid = 10-20" moisture/year

10. How is water measured for irrigation? ä Gallon ä Acre-feet = one acre (43,560 ft) one foot deep ä Barrel = 42 gallons ä Cubic Feet

11. What is Flow? given amount of water in a specific time ä GPM, CFS, CFM, Barrels/day ä Example: ä 100 acres ä apply 8" water ä pump delivers 900 GPM ä how long do you need to run the pump to get 8" water?

12. Answer ä 100 acres x.66' = 66 acre feet ä (66 * 43,560) =2,874,960 CF ä 2,874,960 * 7.48 = ä 21,504,700 gallons ä 21,504,700 / 900 = 23,894 min or 16.5 days at 24 hrs/day

13. What are the types of irrigation? ä Surface Irrigation ä Wild Flooding- hay ä Furrow Irrigation - sugar beets ä Subsurface Irrigation - water from underground ä Aerial Irrigation ä Sprinkler - center pivot, line, wheel line ä Drip or Trickle - water applied directly to plant

14. What is moisture stress? ä plants do not get enough water

15. How do plants deal with moisture stress? ä 1) tolerate - do not grow as tall ä 2) escape - shorten life cycle ä 3) avoid - store water, roll up leaves

16. How can we reduce moisture stress? ä reduce weeds (competition) ä less seed (competition) ä balance fertilizer