January-March 2007 

The USDA NRCS Plant Materials Program newsletter for the conservation community 

Experiment in Sub-Irrigation Tubes Shows Promising Results

Nearly two years ago the Bridger Plant Materials Center 

(PMC) began a unique experiment using PVC piping to

more efficiently deliver water to plants in semi-arid 

environments. The process is accomplished by

infiltrating shrubs and trees with water beneath the 

surface. 

Because sub-irrigation delivers 

water below the soil surface, the 

theory is that roots will grow 

deeper thus helping to increase 

woody plant survival, especially

during periods of drought. 

“Another possible benefit with 

deep watering may be reduced 

soil surface evaporative losses, a 

result of reduced hydraulic 

conductivity as the moisture 

content of the surface dries out,” 

said Joe Scianna, research 

horticulturist at the Bridger, PMC. Ash Tree (above) 

Installing

irrigation tubes 

(right) 

The Bridger study includes four 

species; green ash Fraxinus 

pennsylvanica, bur oak Quercus 

macrocarpa, ponderosa pine Pinus ponderosa, and 

Rocky Mountain juniper Juniperus scopulorum. These 

species were selected because they represent a good mix 

of root system habits and rates of growth. Fifty percent 

of the trees were watered with tubes, the other half were 

hand watered on the soil surface. 

Although it is too early to draw firm conclusions, several 

trends did emerge over the 2005 and 2006 growing

seasons. The tubes did not improve the survival or 

growth rate on either site in 2005. Test excavations 

revealed that little water was reaching the small 

establishing root system in 2005. Almost no water 

appeared to be reaching the upper levels of the soil 

profile. 

“To address this issue without relocating the tubes, 

extensions were added,” said Scianna. “In 2006, only

green ash seedlings with tubes at the fallow site showed 

any superior growth over trees without tubes. This might 

be because the fast growing green ash root systems were 

better positioned to take advantage of the supplemental 

moisture.”

An interesting development is the dramatic difference in 

height growth and vigor rating between the fallow and 

vegetated sites. All species, with the exception of the 

ponderosa pine in 2005, grew much taller and had higher 

vigor ratings, regardless of the manner in which 

supplemental water was delivered, on the fallow site. 

These results are a prime example of the benefits of 

herbaceous vegetation control when 

establishing tree and shrub 

seedlings – at least in semi-arid 

environments and given the amount 

of supplemental water provided. 

“Although refinement of this 

technique will be necessary, the 

study should answer some 

fundamental questions regarding the 

potential usefulness of subirrigation tubes in the real world,” 

said Scianna. 

The project was initiated by Robert Kilian, NRCS Area 

Rangeland Specialist and funded in part by a Grazing 

Lands Conservation Initiative grant. The Montana 

Conservation Seedling Nursery in Missoula, Montana, is 

also partnering on the project. This concept is based on 

similar work conducted at the Los Lunas Plant Materials 

Center in New Mexico.

Contact: Joseph Scianna

Joe.Scianna@mt.usda.gov

Visit us: http://Plant-Materials.nrcs.usda.gov 

Plant Materials Program
e United States Department of Agriculture (USDA) prohibits discrimination in all its programs on the basis of race, color, national origin, gender, religion, age, disability, political beliefs,

sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program

information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD).To file a complaint of discrimination, write the USDA, Director, 

Office of Civil Rights, Room 326W, Whitten Building, 14th and Independence Avenue, SW. Washington, D.C., 20250-9410 or call (202) 720-5964 (voice or TDD). USDA is an equal

opportunity provider and employer. 

Th

Visit us: http://Plant-Materials.nrcs.usda.gov 

A small seed can grow into something great. That is the 

symbolic idea behind the AiKiRuti Healing Garden. 

AiKiRuti – pronounced I-key-ru-dee – is a project 

started by members of the Winnebago Tribe. AiKiRuti, 

which means “helping hand”, hopes to be a helping hand 

in fighting drug and alcohol abuse in the Winnebago 

Tribe and their northeast Nebraska community. 

The healing garden was started in 2002 when over 100 

varieties of indigenous plants significant to the 

Winnebago people were planted at the one-acre site in 

Winnebago, Nebraska. 

Members of the community 

worked to prepare the site for 

planting. The Natural Resources 

Conservation Service (NRCS) 

supplied seed for the garden

through the Nebraska Loess Hill 

RC&D and the NRCS Plant 

Materials Center (PMC) in 

Manhattan, Kansas. The PMC 

has plans to do additional 

seeding in 2007. 

Mark Janzen, plant materials 

specialist at the PMC, said the 

idea behind a healing garden is that plants can bring 

healing and hope to a community. 

“These plants will help focus tribal members back 

towards their cultural heritage and help them identify the 

significance that plants had in their cultural history,” 

Janzen said. 

NRCS Helps Plant Seeds of Hope at Healing Garden 

Members of the Winnebago Tribe have become

enthusiastic about learning the role plants played in their 

cultural history. Local children volunteered to plant 

buffalo grass at the healing garden’s tee pee site. CeCe

Earth, a member of the AiKiRuti organization said this 

provided an opportunity for Winnebago children to 

restore a piece of their tribe’s culture. 

“These kids rode their bikes to the garden to check on 

their grass. They were really excited to see how well it

was growing. It is now one of the most sacred sites in

the garden,” Earth said. 

The AiKiRuti organization wants to 

build a cultural learning/visitors 

center. The center will provide a 

place of cultural discovery for 

members of the Winnebago Tribe, 

and provide an opportunity for nonIndians to participate in cultural and 

educational activities alongside 

members of the Tribe. 

“It can take a long time for a garden 

like this to really start to look like 

something. But if you look closely

you can see some beauty and hope 

 emerging,” Earth said. 

Bob Starck, volunteer with AiKiRuti Healing 

Garden, shows plans of the healing garden to

NRCS State Forester, Constance Miller. 

Hope is what has kept this project moving forward. 

AiKiRuti can also be interpreted as meaning “a hand 

reaching out to help”. Members of the Winnebago Tribe 

are hoping this healing garden will soon live up to its 

name. 

Contact: Joanna Pope, NRCS Public Affairs 

Specialist, at: Joanna.Pope@ne.usda.gov

Helpful Plant Materials Tech Tips: Spring is for Planting – Are you Ready? 

With planting season not too far away, the Plant Materials Program has information on the web to help plan and install 

your new conservation planting. 

Check out our “Seeding and Planting” page at http://plant-materials.nrcs.usda.gov/technical/seeding/ for useful tips on 

planting grasses, wildflowers, trees and shrubs. 

Our Mission: Develop and deliver plant-science technology to meet the nation’s natural resources conservation needs.