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Final national greencentrewater
- 1. Life blood of the ‘Green’ industry
- 2. Water Dr. Ted Bilderback – NC State Univ. Water Quality :Managing the Chemistry in your Irrigation Water Supply Dr. Jim Owen – Oregon State Univ. Dr. Stu Warren – Kansas State Univ.
- 4. Water Dr. Ted Bilderback – NC State Univ. Dr. Jim Owen – Oregon State Univ. Dr. Stu Warren – Kansas State Univ. Getting more plant per gallon
- 7. The Container System FERTILIZER SUBSTRATE IRRIGATION Container
- 10. Let the waters flow
- 15. The Container System FERTILIZER SUBSTRATE IRRIGATION Container
- 16. Irrigation – Getting more plant per gallon
- 19. Pathways of water through a container Channel along edge Follow large pores Held in small pores
- 26. Cyclic irrigation and water movement in containers 1st irrigation cycle 2nd irrigation cycle 3rd irrigation cycle
- 28. Irrigation volume How much to apply? Traditional: inches of water Does that tell you if the substrate is rehydrated?
- 30. Leaching Fraction Leaching Fraction = Volume Leached / Volume Applied Leaching Fraction ~ 0.15 – 0.20 Total Water Applied for container diameter area is measured as “total volume” to calculate leaching fraction
- 31. Plastic bags work for leaching fractions Water Applied Water Leached
- 32. Leaching fraction 7 gal per container Owen. 2006
- 33. Leaching fraction 7 gal per container 90,000 gallons of water saved per growing acre while maintaining growth Owen. 2006
- 35. Less than uniform irrigation distribution? Think Leaching Fraction
- 36. Group by: Water needs Container size Substrate
- 41. Canopy Capture Williamson et al. 2005. SNA 60 80 100 120 140 160 180 200 220 240 260 33 50 72 92 105 Days Percentage irrigation capture Cotoneaster Gardenia Cotoneaster dammeri ‘ Skogholm Gardenia augusta ‘Chuck Hayes’
- 42. Irrigation volume to maintain 0.2 LF 0 100 200 300 400 500 600 700 800 900 22 29 32 40 47 49 54 66 73 82 92 99 105 Days After Initiation Daily volume applied (ml) Cotoneaster Vitex Williamson et al. 2005. SNA Cotoneaster dammeri ‘Skogholm Vitex trifolia ‘Variegata’
- 48. Dry weight of Cotoneaster dammeri 'Skogholm' Dry weight (g) b a a a c b a b d c a b
- 49. Rainfall Weeks After Initiation Rainfall (mm)
- 51. Rainfall Weeks After Initiation Rainfall (mm)
- 52. Dry weight of Cotoneaster dammeri 'Skogholm' Dry weight (g) b a a a c b a b d c a b
- 55. Monitoring Water Use Water gain
- 56. Monitoring Water Use Water gain Plant water use Daylight hrs
- 61. Irrigation timing - overhead Williamson et al. 2005. SNA Substrate Temperature (C) Aug 26 Aug 27
- 62. Irrigation timing - overhead Williamson et al. 2005. SNA Substrate Temperature (C) Aug 26 Aug 27 12:00 3:00 6:00 Pre-Dawn
- 63. Irrigation timing - overhead Williamson et al. 2005. SNA Substrate Temperature (C) Aug 26 Aug 27 3:00 AM 9:00 PM
- 66. Questions
Editor's Notes
- There are a lot of questions about overhead irrigation . Where can you find answers?
- These two concerns have us focusing on substrate Current Substrates used in the SE-USA contain pine bark and sand, which our inert and have little ion exchange capacity or water retention Therefore if we change the substrate by adding the proper ammendment we can effect both container nutrition and available water. So we chose clay as our ammendment due to the previous work by Warren and Bilderbach that showed increased available water and nitrate, ammonium and phosphorus by adding arcillite to pine bark substrates
- There are a lot of questions about overhead irrigation . Where can you find answers?
- There are advantages and disadvantages for nurseries considering application of irrigation in multiple cycles.
- Trade magazines, and association newsletters foretell of impending water rights disputes.
- These two concerns have us focusing on substrate Current Substrates used in the SE-USA contain pine bark and sand, which our inert and have little ion exchange capacity or water retention Therefore if we change the substrate by adding the proper ammendment we can effect both container nutrition and available water. So we chose clay as our ammendment due to the previous work by Warren and Bilderbach that showed increased available water and nitrate, ammonium and phosphorus by adding arcillite to pine bark substrates
- There are advantages and disadvantages for nurseries considering application of irrigation in multiple cycles.
- Multiple irrigation cycles with a programmed rest cycle (30 minutes to 2 hr) between irrigation applications moves a wetting front through the profile of the container. Between cycles, water held in the wetting front wets adjacent substrate particles eliminating dry pockets within the substrate. The last irrigation cycle is run for enough time to push the wetting front to the bottom of the container with an excess of approximately 20% (0.2 LF). Research has shown that for pine bark substrates, an excess of approximately 20% leaching is required to fully wet the entire volume of substrate in the container.
- There are advantages and disadvantages for nurseries considering application of irrigation in multiple cycles.
- Guessing about how much water you apply based upon how long the irrigation runs, is usually an unreliable method to begin assessing best management options. A start is to placed rain gauges in several containers in an irrigation zone. This is a method to measure the volume of water applied and to assess uniformity of the amounts of water applied within the growing bed.
- Impact sprinklers inherently apply more water closer to the riser and less water at the edges of the patter. When considering what plants to put in the same irrigation zone, thinking out of the box may require thinking about the bucket! There may be ways to take advantage of less than uniform irrigation. If water gather plants are on the edge of the pattern and smaller plants or ones that do not gather as much water are closer to risers, it may be more of a compatible set up than it appears. How do you know? Put some buckets under pots and measure leaching fractions. How different are they?
- Measuring leaching fraction is as simple as placing buckets under containers. The empty container measures the amount of water applied that could potentially enter that circular are of the container. The container holding the plant and potting substrate measures the amount of drainage after water lost through plant use (transpiration) and evaporation are replaced. Approximately 10 to 20% leaching is considered appropriate for leaching excess salts and re-wetting the substrate.
- If a tight fitting bucket is not available to place containers in, plastic bags work fine.
- Benefits beyond growing plants under optimal irrigation practices include saving water and electrical energy required to pump it. Fertilizer may last longer as well.
- How often should a nursery measure leaching fractions? Monthly measurements are reasonable. Possibly more frequently when plants are growing rapidly or trouble shooting is required. Leaching fractions are calculated weekly in university research studies.
- Monitoring leaching fractions is the best technique to use to determine how much water to apply. The goal is to maintain a 0.1 to 0.2 leaching fraction. How long should irrigation run? Do plants need more water as they grow? What happens when plants grow beyond the edge of the container? What crops can best be placed in the irrigation zone? Monitoring leaching fractions on a regular basis can answer these questions.
- Impact sprinklers inherently apply more water closer to the riser and less water at the edges of the patter. When considering what plants to put in the same irrigation zone, thinking out of the box may require thinking about the bucket! There may be ways to take advantage of less than uniform irrigation. If water gather plants are on the edge of the pattern and smaller plants or ones that do not gather as much water are closer to risers, it may be more of a compatible set up than it appears. How do you know? Put some buckets under pots and measure leaching fractions. How different are they?
- Can the top of a plant effect how much water gets into the container to the roots?
- Note in this slide the variety of crops being irrigated in the same zone. At least four types of crops are in this same zone including blue rug juniper, which is a conifer; japanese barberry, which is deciduous; and buddleia, which is a perennial. Do these crops all have the same irrigation requirements? How can a grower manage irrigation if multiple crops with multiple irrigation requirements are located in the same irrigation zone? Which of these crops needs the most water and which need less water?
- Plants with umbrella shade canopies may reflect water away from entering the surface area of containers. In this case, leaching fractions are reduce and Interception Efficiency is reduced. Potential Runoff would be increased in cases where water is deflected from entering containers. Research at NCSU has shown that cotoneaster seen in this slide has no effect on leaching fraction. The reason is presumed to be that leaves are small and do not deflect irrigation droplets.
- Gardenia has a vase or funnel shaded canopy. After approximately 100 days of a growing season, gardenia intercepted approximately 240% more water than was collected in empty containers of the same diameter.
- A similar comparison shows that after 33 days, cotoneaster and ‘Chuck Hayes’ gardenia captured the same amount of irrigation as the empty container. The gardenia has a funnel type plant architecture and by 105 days gathered 240% more irrigation than was collected by the empty container. Cotoneaster has an umbrella shaped canopy but the small leaves that do not interfere with irrigation application so cotoneaster intercepted only slightly more water that was captured by the fallow container.
- In a study conducted at N.C. State, leaching fractions were measure weekly. Approximately 400 ml of irrigation water was required to maintain a 0.2 leaching fraction for cotoneaster and vitex for the first 22 day after potting. After 54 days, plant canopies grew beyond the diameter of the pot. Vitex with a funnel or gathering type architecture intercepted enough irrigation that only 200 ml of applied irrigation (empty container) was required on day 105.
- Note in this slide the variety of crops being irrigated in the same zone. At least four types of crops are in this same zone including blue rug juniper, which is a conifer; japanese barberry, which is deciduous; and buddleia, which is a perennial. Do these crops all have the same irrigation requirements? How can a grower manage irrigation if multiple crops with multiple irrigation requirements are located in the same irrigation zone? Which of these crops needs the most water and which need less water?
- Does the time of day irrigation is applied make a difference in plant growth?
- A study conducted at N.C. State University compared cycled irrigation cycles. In the study 3 irrigation cycles 2 hours apart were applied 1) pre-dawn at 2,4,6 am; 2) AM (mornings) at 6 am, 9am and 12 noon; 3) PM (afternoons) at 12 noon, 3pm, and 6pm; or 4) All Day at 6 am, 12 noon and 6 pm.
- Container temperatures were significantly lower in all day and pm irrigation cycles for as long as 12 hours compared to pre-dawn irrigated containers.
- A drop in container substrate temperatures were consistent with each irrigation cycle for all day and pm irrigation cycles with major temperature differences occurring from 12 noon to 6 pm coinciding with each irrigation event.
- Containers irrigated with pm cycles remained cooler than all day cycles until approximately 9 pm (3 hours after the last irrigation). Containers irrigated with pm and all day cycles were cooler than pre-dawn cycles until approximately 3 am the next day.
- Choosing the time of day to irrigate can influence plant growth. Nurseries must determine if irrigating during day light hours is appropriate for their operations.
- There are a lot of questions about overhead irrigation . Where can you find answers?