Irrigation Chapter 7 What is irrigation the controlled
- Slides: 17
Irrigation Chapter #7
What is irrigation? ä the controlled application of water ä xerophytes, mesophytes, hydrophytes
What is transpiration? ä plants give off water in the form of a gas ä 99% of water is transpired
What is Transpiration Ratio? ä pounds of water transpired for each pound of dry matter produced (table page 74)
What is water use efficiency? ä pounds of dry matter produced per inch of water used
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)
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
What is climate? ä the amount of water throughout the season
What is the climate in Northeast Montana? ä semi-arid = 10 -20" moisture/year
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
What is Flow? given amount of water in a specific time ä GPM, CFS, CFM, Barrels/day ä Example: ä 100 acres apply 8" water ä pump delivers 900 GPM ä how long do you need to run the pump to get 8" water? ä
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
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
What is moisture stress? ä plants do not get enough water
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
How can we reduce moisture stress? ä reduce weeds (competition) ä less seed (competition) ä balance fertilizer