E8-16024. Notice of Proposed Changes to the Natural Resources Conservation Service's National Handbook of Conservation Practices

AGENCY:

Natural Resources Conservation Service, USDA.

ACTION:

Notice of availability of proposed changes in the Natural Resources Conservation Service (NRCS) National Handbook of Conservation Practices for public review and comment.

SUMMARY:

Notice is hereby given of the intention of NRCS to issue a series of revised conservation practice standards in its National Handbook of Conservation Practices. These standards include: Residue Management, Seasonal (Code 344); Grassed Waterway (Code 412); Mulching (Code 484); Stripcropping (Code 585); Cross Wind Ridges (Code 588); Terrace (Code 600); Underground Outlet (Code 620); and Water and Sediment Control Basin (Code 638). NRCS State Conservationists who choose to adopt these practices for use within their States will incorporate them into Section IV of their respective electronic Field Office Technical Guide. These practices may be used in conservation systems that treat highly erodible land or on land determined to be a wetland.

DATES:

Effective Dates: Comments will be received for a 30-day period commencing with this date of publication. Final versions of these new or revised conservation practice standards will be adopted after the close of the 30-day period, and after consideration of all comments.

ADDRESSES:

Comments should be submitted by one of the following methods:

1. In writing to: National Agricultural Engineer, Natural Resources Conservation Service, Post Office Box 2890, Washington, D.C. 20013-2890; or

2. Electronically via e-mail to: [e-mail].

FOR FURTHER INFORMATION:

Copies of these standards can be downloaded or printed from the following Web site: ftp://ftp-fc.sc.egov.usda.gov/NHQ/practice-standards/federal-register/. Single copies of paper versions of these standards also are available from NRCS in Washington, DC. Submit individual inquiries in writing to Daniel Meyer, National Agricultural Engineer, Natural Resources Conservation Service, Post Office Box 2890, Room 6139—South, Washington, DC 20013-2890; or e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

The amount of the proposed changes varies considerably for each of the Conservation Practice Standards addressed in this Notice. To fully understand the proposed changes, individuals are encouraged to compare these changes with each standard's current version shown at: http://www.nrcs.usda.gov/​technical/​Standards/​nhcp.html. To aid in this comparison, following are highlights of the proposed revisions to each standard:

Residue Management, Seasonal (Code 344)—Substantial changes are reflected in the proposed revision to this standard:

(a) One new purpose was added to address soil condition.

(b) Under the “General Criteria” section, (1) the option to burn residue was removed, as burning residue is not compatible with the purposes of the practice; and (2) tillage operations permitted during the residue management period is limited to undercutting tools.

(c) The tillage criteria were removed from the “Criteria to Reduce Sheet and Rill and Erosion from Wind” and the “Criteria to Provide Food and Escape Cover for Wildlife” sections of the standard. Criteria were added to the “Additional Criteria to Improve Soil Condition” section. Under the “Criteria to Manage Snow to Increase Plant-Available Moisture” section, (1) the criteria for harvesting equipment stubble height was removed since this is covered in the trapping snow criteria; and (2) the tillage and field operations criteria was revised to be done perpendicular to the direction of the prevailing winds.

(d) The “Considerations” section was revised to include PM-10, soil organisms, and cover crops.

Grassed Waterway (Code 412)—Only one significant change is proposed to this standard:

(a) The “Criteria” section, under the Stability subsection, was changed to require stability analysis based on tractive stress, rather than the velocity approach previously required.

Mulching (Code 484)—Significant changes are proposed for this standard:

(a) The “Purpose” section was revised by (1) adding a purpose for reduction of airborne particulates; and (2) removing increased soil fertility from the “improve soil condition” purpose.

(b) Under the “General Criteria” section, (1) Animal manure was removed as an acceptable mulching material; (2) criteria were added to the use of manufactured mulches, and that the rate specified by the manufacturer is the “minimum amount” that is acceptable; and

(3) Criteria were added that the mulch material also must be free from pesticides and chemicals that may impede the planned use of the mulch.

(c) Under the “Criteria for Soil Moisture” section, the criteria requiring the mulch be applied prior to soil moisture loss were removed. Under the “Criteria for Erosion Control” section, the criteria that the mulch cover shall not exceed 80 percent for wood products and 90 percent for gravel/inorganic mulches were removed. Under “Criteria to Establish Vegetative Cover” section, the minimum cover was changed from 50 percent to 70 percent. Under the “Criteria for Soil Condition” section, all the criteria for animal manure and fertility were removed.

Stripcropping (Code 585)—Only minor changes have been proposed to this standard:

(a) The “General Criteria” section has been revised to require (1) Equal strip widths for erosion susceptible strips and erosion resistant strips; (2) that at least 50 percent of the rotation shall consist of erosion resistant crops or sediment trapping cover; and (3) that the same rotation shall be followed in each adjacent strip, while the year of the rotation is staggered to maintain alternating strips in an erosion resistant crop or cover.

(b) Under the “Additional Criteria for Soil Erosion by Water * * *” section, the criteria for maximum row grade have been modified to be the same as the Contouring Standard (330), and criteria for cover conditions on the field headlands/end rows have been added.

(c) The “Considerations” section of the standard was revised to remove the specific considerations for each of the practice purposes.

(d) The “Operations and Maintenance” section of the standard was revised to remove the specific operation and maintenance for each purpose and combined into one common list of activities for operation and maintenance.

Cross Wind Ridges (Code 588)—Substantial changes are proposed for this standard:

(a) The practice code is being changed from 589A.

(b) The “Purposes” section has been expanded to include providing protection to crops from wind-borne soil particles and to reduce soil particulate emissions to air.

(c) The criteria for design of ridge height and spacing have been changed to reflect changing prediction technologies, and additional criteria have been added to address directional placement and minimum spacing.

(d) The “Considerations” section has been greatly expanded to optimize use of the standard.

Terrace (Code 600)—Significant editing is proposed for the standard:

(a) Design information that is contained in other Agency technical references, such as the Revised Universal Soil Loss Equation parameters and equations for computing ridge heights, has been removed. Otherwise, the “Criteria” section of the standard has not been substantially altered.

Underground Outlet (Code 620)—Considerable editing to the standard is being proposed:

(a) To add clarity and readability, every section of the standard has been rewritten. However, the underlying design requirements contained in the “Criteria” section have not been significantly modified from the current version of the standard.

Water and Sediment Control Basin (Code 638)—Considerable editing to the standard is being proposed:

(a) Every section of the standard has been rewritten to add clarity and readability. However, the underlying design requirements contained in the “Criteria” section have not been significantly modified from the current version of the standard.

(b) The “Considerations,” “Plans and Specifications,” and “Operations and Maintenance” sections have been significantly expanded.

Section 343 of the Federal Agriculture Improvement and Reform Act of 1996 requires NRCS to make available for public review and comment all proposed revisions to conservation practice standards used to carry out the highly erodible land and wetland provisions of the law. For the next 30 days, NRCS will receive comments relative to the proposed changes. Following that period, a determination will be made by NRCS regarding disposition of those comments, and a final determination of changes will be made.

Signed in Washington, DC, on July 2, 2008.

Arlen L. Lancaster,

Chief, Natural Resources Conservation Service.