HRT 310 Nursery Management exam 2

Environmental Factors for site selection

Climate: rainfall, temp, wind, hail

Topography

Soils

Water

Air

Economic Factors for site selction

Land Cost

Labor cost and availbility

Facilities/utilities

Competition

Transportation

Local taxes, permits, zoning

Biological factors for site selection

insects/pests

disease

weeds

mammals

How do you determine spacing in planting design for seed and liner beds

seed: width 3 to 5 ft and spacing of seeds is determined by germ rate

Liner: depends on final size of liner, rows usually 3 to 12 in apart and wider spacing between plants than seed beds

How do you determine spacing for field grown crops

in row: final width of crop

between row: final width of crop + minimum equipment operating width

How do you determine spacing for container grown crops?

Spacing is based on the final size of the container plants and their growth rate, typically allowing for airflow and light.

What factors affect slecetion of a particular design?

land cost, equipment size and cultural practice, desired plant size

What are the three plantinf designs disscussed in class

rectangular, rectangle-square, and equilateral triangle-hexagon

What is the most eficent planting design

equilateral triangle hexagon

What is harvesting on the diagonal?

same plant in diagnol path and harvest all those. it keeps square spacing

What planting design is harvesting on the diagonal used for and why?

square in rowplanting design, as it allows for efficient harvest of crops positioned in a square layout.

Soil/Substrate infiltration rate

The speed at which water permeates through soil or substrate. This measurement is crucial for understanding water management and drainage in nursery applications.

Pulse or cyclic irrigation

a method of irrigation where water is applied in short, repeated bursts or pulses, allowing better moisture absorption and minimizing runoff.

Irrigation Distribution Uniformity

A measure of how evenly water is distributed across a field or growing area during irrigation. High uniformity is essential for efficient water usage and optimal crop growth.

Irrigation Efficiency (relation to water delivery)

Volume of water delivered to the target (pot) divided by volume of
water input into the system

Irrigation Efficiency (crop yield)

Increase in crop yield over non-irrigated yield divided by water
applied through irrigation

Crop Water Use Efficiency

crop yield divided by
volume of water to produce the crop

Why do we irrigate

necessary for container prod

increase growth rate

improved transplant surviva;

consistent prod schedule

ease of digging/plantin

fertilizer solvent

winter-frost protecting

seals in and activates herbicides

What are the concerns when irrigating, especially for container production? Why are they
important?

Overhead: up to 80% misses target
• Over-irrigation = Leaching and/or runoff
• Leaching = loss of nutrients
• Loss of nutrients =
• Wasted $, slower growth, decreased quality
• Nutrients and other chemicals in runoff
• Increased disease and other pest pressure = increased cost of managing
them and loss of plants
• Runoff = possible movement of nutrients and pesticides off-site
• Environmental concerns
• Water use regulations

What are the required irrigation reporting practices by MDARD?

if a nursery is pumping >70 gal/min or 100,000 gal/day it must track and report monthly water use annually

Why is it important to know the infiltration rate?

because irrigation should not be supplied at a rate higher than the infiltration rate

What can affect infiltration rate?

type of soil (loamy, sandy, silty) and the %slope

How do most backflow prevention devices work? Why should they be used?

They use a valve system to prevent contaminated water from flowing back into the potable water supply, protecting it from pollutants. These devices create a physical barrier that stops backflow and should be used to ensure safe drinking water and comply with health regulations.

What is the difference between Microsprinklers, Sprayers/Spray Stakes, and Drip irrigation
emitters? What are the advantages and disadvantages of each? How do they compare with more
traditional overhead irrigation systems?

Microsprinklers distribute water over a larger area than drip irrigation but less densely than spray stakes. Spray stakes provide a more targeted application than overhead systems but can be prone to wind drift. Drip irrigation delivers water directly to the root zone, which minimizes evaporation and runoff, making it efficient for water conservation. Each system has specific applications based on water needs, plant type, and topography.

What are the 7 conservation techniques

Schedule irrigation on plant demand, not a set
daily amount
• Group plants by water demand
• Check irrigation pattern uniformity regularly
• Rain shut off device
• Use maximum pot spacing efficiency
• Reclaim and recycle runoff
• Cyclic or Pulse Irrigate

Describe capillary irrigation; subirrigation (flood or ebb and flow)

Capillary irrigation involves the movement of water through soil or growing media via capillary action, allowing plants to absorb moisture from their surroundings. Subirrigation, including flood or ebb and flow methods, supplies water from below the plant roots, promoting growth while minimizing surface evaporation and reducing water waste.

What is the lowest irrigation distribution uniformity acceptable for overhead irrigation?

80%

What is the lowest irrigation distribution uniformity acceptable for indvidual plant irrigation?

80%

Why is it important to have high irrigation DU?

High irrigation distribution uniformity (DU) is important because it ensures that water is applied evenly across the whole area, which promotes healthy plant growth, maximizes water efficiency, and reduces the risk of overwatering or underwatering specific areas.

What are some causes of low DU?

Improper irrigation pipe selection
• Improper operating pressure
• Inadequate selection of irrigation sprinklers or emitters
• Inadequate sprinkler overlap
• Wind effects
• Time- affects pump efficiency, pressure regulation, nozzles
• Blocking or damage of emitters

What basics should be considered when designing an overhead irrgation system for a rectangular head with respect to overlap and arc of heads?

Consider the spacing of the heads, the arc coverage of each sprinkler, and the amount of overlap needed to ensure even distribution of water without dry spots.

Steps for determining DU for an overhead irrigation system?

Place collection cans (straight sided) in a grid in
irrigation block to be tested.
• Run irrigation system for at least 15 minutes, regular
irrigation cycle recommended.
• Measure depth of water in each can.
• Determine average of depths in each can.
• Determine average of lowest 25% of cans.
• Divide average of the lowest by the overall average to
get DU.%.

steps for an irrigation system delivering water to individual plants (drip, spray stake). Why should you keep
track of catch can or emitter location?

Measure time to fill identical bottles from at least 18 emitters per irrigation
zone.
• Sum the lowest 1/6 of the measurements.
• Sum the highest 1/6 of the measurements.
• Plot the point on the following nomograph.
• Nomograph will show DU range, want greater than 80

What daily, weekly and 6 month irrigation checks should you conduct?

Daily Irrigation Checks
• Amount applied is appropriate for container size and plant type
• Operation of nozzles (rotation, pattern, fogging)
• Moisture content of substrate before watering
• Drainage from containers
• Rain gauge to check if system ran

Weekly Irrigation Checks
• Flow rate and pressure at pump outlet and inlets to each zone
• Plants grouped in zones according to water requirement
• Plants spaced so canopies just touch
• Read all flow meters
Additional for low volume systems:
• Emitter placement and clogging
• Filters cleaned and checked
• Lateral lines flushed
• Cleaning agent injectedSix Month Irrigation Checks
• Nozzle pressure with pitot tube
• Wear of nozzles with drill bit or other item
• Risers are vertical
• DU in several locations
• Water penetrating canopies of representative plants
• Sprinkler heads and nozzles are uniform in each zone
• Rain shut-off
• Water holding capacity of substrate for container sizes
• Pump performance- flow, pressure
• Check if zones are running according to controller

What are common causes for loss of irrigation system efficiency?

Non-uniform application
• Poor system design
• Improper installation
• Poor management
• Equipment failures
• Excessive or inadequate application
• Evaporation/drift
• Runoff (surface or subsurface)
• Leaks in pipes

What is the relation between pot spacing and irrigation efficiency?

more space you have between pots less water is hitting plants

Water Quality Star this

The concentration and load of chemical elements and compounds and organic and biological
contaminants in water that make it suitable or unsuitable for growing plants.T

3 Main sources of irrigation water + their advantages and disadvantages

Well (Groundwater)
• Often (not always) best quality, less disease
• Expense (installation), quantity, rights/regulations
Surface Water
• Disease, contamination, algae, soluble salts, land
• Recycling, rights/regulations
Municipal water
• Low soluble salts
• Unreliable, expensive, possibly unavailable
• Insufficient quantity for most wholesale nurseries

Ripararian and Water Use Rights

Water rights belong to property
owner adjacent to or above water
source.
Upstream owners can not
unreasonably interfere with rights
of downstream owners.
Can be modified by legislation

What is the relationship between drawdown, transmissivity and yield of an aquifer and suitability of a high capacity well? How does this relate to site selection?

The drawdown refers to the reduction in water level caused by pumping, while transmissivity is a measure of how easily water can move through an aquifer. Yield is the amount of water a well can deliver over time; these factors determine the suitability of a high-capacity well and influence site selection based on the aquifer's ability to provide sufficient and sustainable water resources.

Draw a simple diagram through the soil profile that shows the water table, glacial aquifer and 2
confined aquifers. What is the difference between these water sources?

Contrast gaining streams, losing streams and disconnected streams. Are these terms applicable to
lakes and ponds? Why is it important to understand water flow in these systems for irrigated
agriculture

Gaining streams receive water from the surrounding groundwater, losing streams contribute water to the groundwater, and disconnected streams do not interact with groundwater. These terms can apply to lakes and ponds, influencing water availability and management practices essential for irrigated agriculture.

Diagram a gaining, losing, disconnected surface water source. What happens if you install a very
high capacity well near the water source that redirects water away from that source? What are the
ramifications of the change in water movement as it progresses from mild to extreme in
diversion

List in order of importance for container production the water quality considerations discussed in
class. What are the water quality guidelines ranges for good, some problem and problem needing
management for bicarbonates and soluble salts (include the unit of measure)?

In relation to the terms used for irrigation water quality, what is the difference between pH and
alkalinity?

How would you manage irrigation water with an alkalinity value of 45 ppm? 190 ppm? 550
ppm? Defend your management choices

45- is less than 60 ppm so no action neccesary

190- monitor substrate pH regulary, reduce amount of lime used, irrigate more efficiently, and use acid-forming ferts

550- incorporate or topdress with S,Fe2(SO4),Al2(SO4)3

In what situations would you inject acid to manage water quality? What types of acid are
typically used? Which ones are important for production (other than water quality) and
environmental considerations?

n what situations would you inject acid to manage water quality? What types of acid are
typically used? Which ones are important for production (other than water quality) and
environmental considerations?

What are the management strategies for water with high soluble salts? With high sodium? With
high chloride? What is the difference between chloride and chlorine?

What are the management strategies for water with compounds that can result in leaf residues?

Why are there additional water quality considerations for microirrigation systems?

Five main methods of water sanitation were discussed. What are they and how do they work?
What is the most commonly used sanitizer type?

pH is important when using chlorine sanitizers. In general, what pH is best for chlorine
sanitizers? Why?

When injecting sanitizers, especially chlorine types, what are the injection considerations to
remember? Why are they important?

What free chlorine concentration is desired at the end of irrigation lines for continuous injection
with water pH > 7? With water pH < 7? What is it for periodic injection to clean irrigation lines?
What is it for shock treatments to remove biofilms? What happens if water from periodic
cleaning injections or shock treatments contacts plants? How should you handle this water?

Is reverse osmosis a viable treatment for wholesale production nurseries? In what situations
might a wholesale nursery use reverse osmosis water?

Define Irrigation Return Flow

What are the advantages and disadvantages of using recycled irrigation water? What are some
things that can be done to improve recycled irrigation water quality? How is handling recycled
irrigation water different from handling irrigation return flow?

Starr- Concentration

is the mass or volume of contaminant per volume of water: mg/L, ppm

Starr- Load

cumulative mass or volume of the contaminant delivered to the same location over a
period of time: tons/week, kg/day, lbs/hr