![](media/image1.png){width="6.5in" height="0.6in"}Natural Resources
Conservation Service

6200 Jefferson NE

Albuquerque, New Mexico 87109

**Phone**: (505) 761-4400 **Fax**: (505) 761-4462

**Web site**: [www.nm.nrcs.usda.gov]{.underline}

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![](media/image2.png)October 5, 2004

**New Mexico AGRONOMY TECHNICAL NOTE NO.28 revised**

**SUBJECT: ECS REVISED UNIVERSAL SOIL LOSS EQUATION Version 2**

**[Purpose]{.underline}**: To distribute a revision to Agronomy
Technical Note No. 28.

**[Effective Date]{.underline}**: When contents have been noted.

**[Filing Instructions]{.underline}:** Discard when noted.

This is a complete rewrite of this note because the change from RUSLE
version 1 (paper version) use up to the end of FY 2004 is a completely
different model. The old version used a simple five factor
multiplication. RUSLE 2 has been fully implemented in NM and must be run
on a computer with the NM databases.

NM generally does not have sheet and rill water erosion rate that exceed
T. However, the new model can be used to estimate sediment delivery to
the bottom of a given slope. There may be a need to use it for water
quality purposes.

The new model **must be run** to establish a Soil Condition Index. This
is required to establish a complete resource management system on
cropland and hayland.

KENNETH B. LEITING

State Resource Conservationist

Attachment

Dist:

AC (4)

DC (37)

Ecological Sciences Division, Washington, DC (2)

Adjoining States --- UT, CO, TX, OK, AZ (1 each)

Technical Services (1 file)

AGRONOMY TECHNICAL NOTE

  ------------------------------ ----------------------------------------
  **US DEPARTMENT OF             **NATURAL RESOURCES CONSERVATION
  AGRICULTURE**                  SERVICE**

  **AGRONOMY - 28**              **Albuquerque, NM**

                                 **Revised October, 2004**
  ------------------------------ ----------------------------------------

**REVISED UNIVERSAL SOIL LOSS EQUATION Version 2**

# **Preface**

This is a complete rewrite of this note because the change from RUSLE
version 1 (paper version) used up to the end of FY 2004 is a completely
different model. The old version used a simple five factor
multiplication. RUSLE 2 has been fully implemented in NM and must be run
on a computer with the NM databases.

NM generally does not have sheet and rill water erosion rate that exceed
T. However, the new model can be used to estimate sediment delivery to
the bottom of a given slope. There may be a need to use it for water
quality purposes.

The new model must be run to establish a Soil Condition Index. This is
required to establish a complete resource management system on cropland
and hayland.

**Executable Program**

The program can be down loaded from the national website at:
<ftp://fargo.nserl.purdue.edu/pub/RUSLE2/RUSLE2_Program_File/> NRCS
staff will not need to down load the program from the site.

There are other useful information listed on the above site.

**New Mexico RUSLE 2 Database**

NRCS FOs will have a statewide database held on the FOs server in the
S:\\\\RUSLE 2 directory. Staff is reminded that they will need to be
sure they "open alternate" and navigate to the FO database. FOs will
have permissions to save management files to the "c. Other" directory.
Non NRCS staff should use the current database held on the NM NRCS
website <http://www.nm.nrcs.usda.gov/technical/tech-notes/agro.html>

Any questions on file management, crops, and operations should be
directed to the State Agronomist. State database management and model
management will be done remotely when possible.

**About RUSLE 2**

RUSLE2 was developed primarily to guide conservation planning, inventory
erosion rates and estimate sediment delivery. Values computed by RUSLE2
are supported by accepted scientific knowledge and technical judgment,
are consistent with sound principles of conservation planning, and
result in good conservation plans. RUSLE2 is also based on additional
analysis and knowledge that were not available when RUSLE1 was
developed. RUSLE2 is based on science and judgment that is superior to
that of RUSLE1. Lessons learned from using RUSLE1 are incorporated into
RUSLE2.

RUSLE2 has evolved from a series of previous erosion prediction
technologies. The USLE was entirely an empirically based equation and
was limited in its application to conditions where experimental data
were available for deriving factor values. A major advancement in RUSLE1
was the use of subfactor relationships to compute C factor values from
basic features of cover-management systems. While RUSLE1 retained the
basic structure of the USLE, process-based relationships were added
where empirical data and relationships were inadequate, such as
computing the effect of strip cropping for modern conservation tillage
systems.

RUSLE2 is another major advancement over RUSLE1. While RUSLE2 uses the
USLE basic formulation of the unit plot, the mathematics of RUSLE2 are
on a daily basis. Improved cover-management subfactor relationships are
used in RUSLE2, a new ridge subfactor has been added, and the deposition
equations have been extended to consider sediment characteristics and
how deposition changes these characteristics. It includes new
relationships for handling residue, including resurfacing of residue by
implements like field cultivators.

The major visible change in RUSLE2 is its new, modern graphical user
interface. It makes the model easy to use, but is extremely powerful in
the information that it displays and the types of situations that it can
represent. RUSLE2 is a very powerful model yet it uses very simple, easy
to obtain inputs.