Colorado Water Feb 2006

• Year: 2006
• Title: Colorado Water
• Author: Water Center of Colorado State University
• Description: February 2006 Issue
• Publications - Doc Type: Newsletter

Editor's note: The following three articles are transcribed from the presentations made by the CSUpanel
of professors. Lou Swanson also participated in this panel, and his comments were published in the August
2005 issue of Colorado Water.
Dryland Cropping
by Danny H. Smith, Professor
Colorado State University Dept. of Soil and Crop Sciences
Thank you Reagan. When I got the assignment
from Reagan, he mentioned that I should look at
some of the best examples of how Soil and Crop
Sciences research has contributed to agricultural
production in the state and how some of that
expertise might be able to interface with the water
roundtable process. My own personal research
background over the last 10 or 15 years has been
largely associated with consumptive water use
by forage crops in Colorado; mostly confined to
mountain meadow regions. We've been trying to
come up with simplified accounting methods in
the realm of micrometeorology whereby we can
accurately account for water demand by moun-
tain meadows, using techniques that rely only on
temperature.
Thinking more broadly, expertise beyond the
realm of traditional water management research
would likely provide greater benefit to these
roundtables. The kind of expertise they're going
to need occurs at the margins of water manage-
ment, approaching concepts we have traditionally
considered in dryland crop management systems.
Why is this true? Irrigated agriculture currently
controls about 85% of the developed water re-
sources in the state. The tremendous expansion
of urban growth occurring along the Front Range
combined with the fact that three of our four major
water basins are overappropriated, the logical
conclusion is that agriculture is going to be giv-
ing up water. We're going to see conversion of
irrigated acres either to fallow land (most likely
grassland or rangelands, much like those that
existed before white settlers got here), to dryland
acreage, or some combination of those, along with
some minimally irrigated acres. These changes
aren't all that new. As Justice Hobbs indicated in
his luncheon address, the trend began many years
ago, and we're several decades into this transi-
tion from irrigated agriculture to some other form
of land use, especially in the two major basins in
Eastern Colorado.
Given these realities, I briefly surveyed the best
examples of ongoing research within our de-
partment of Soil and Crop Sciences that would
accommodate the need for knowledge in this new
arena? Alternatively, what research results do
we have that will enable us to predict the impact
of the conversion of irrigated lands to dryland
farming in Colorado? Our department has a rich
history of research into dryland farming manage-
ment, dating from the inception of the Ag Experi-
ment Station This traditional area of research
received an added boost in the mid 1980s when
a new phase of comprehensive research and
outreach was initiated, which involved a more
systematic study of dryland farming systems in
Eastern Colorado. The research used a series of
plots stretching from Sterling in the northeast to
Walsh in the southeast. The researchers focused
on two things: first, the use of minimum tillage.
That was not new, certainly, but they combined
that with the consideration of alternative crop ro-
tation systems designed to take maximum advan-
tage of the increased capture of natural precipita-
tion. Results from these studies demonstrated
that we can dramatically increase crop production
per acre on an annual basis by converting from a
conventional wheat fallow system to an alterna-
tive system where one obtains two crops out of
every three years.
This dryland cropping system research incor-
porated another unique approach, and it shows
the additional foresight of the leaders of this