Section 312 IAC 25-6-121 - Underground mining; revegetation; sampling techniquesAuthority: IC 14-34-2-1
Affected: IC 14-34
Sec. 121.
(a) Success of revegetation is evaluated according to the standards as set forth in section 120 of this rule and (if a measurable success standard applies) using sampling techniques set forth in this section or that: (1) have a ninety percent (90%) statistical confidence interval (in other words, a one (1) sided test with a ten-hundredths (0.10) alpha error); and(2) are approved by the director.(b) The following methods may be used to evaluate ground cover: (1) The percentage of ground cover shall be assessed within one (1) square foot units randomly located in the area under evaluation. Each unit shall be divided into one hundred (100) equal parts to form a grid. The percentage of ground cover within each unit is equal to the number of parts that contain vegetation or litter. The minimum number of observations for the area under evaluation and methods of analysis shall be determined under section 122 of this rule.(2) The percentage of ground cover shall be assessed by determining the number of points at one (1) foot intervals that intersect ground cover along one hundred (100) foot lines randomly located in the area under evaluation. A point shall be considered as intersecting ground cover when the location immediately under the point contains either the aerial parts of the vegetation or litter that is produced naturally on-site. The percentage of vegetative ground cover assessed for each line is an individual observation. The minimum number of observations for the area under evaluation and the methods of analysis are determined under section 122 of this rule.(c) The following methods may be used to evaluate the production of living plants on cropland used for hay and on pastureland:(1) With respect to a whole field harvest, all vegetation under evaluation shall be cut, adequately cured under acceptable agronomic practices, and baled. The total number of bales produced per cutting from the area under evaluation shall be determined. The weight of individual bales randomly selected from the area under evaluation shall be determined. The weight of each bale shall be considered an individual observation for the purposes of section 122 of this rule. The minimum number of bales to be weighed shall be determined using the following table: | Size of Area under Evaluation (Acres) | Minimum Number of Small Bales (Less than 100 pounds) | Minimum Number of Large Bales (At least 100 pounds) |
| 0-39 | 10 | 4 |
| 40-279 | 15 | 6 |
| 280-639 | 20 | 10 |
For areas larger than six hundred forty (640) acres, one (1) additional bale is required for each additional thirty-five (35) acres. The adequacy of the sample and the mean weight of the bales shall be determined using the methods set forth in section 122(c) and 122(e) of this rule. The production of the area under evaluation shall be determined using the following formula:
P = (X × NB) (A × 2,000) Where:
P = Production of area (tons per acre).
X = Mean weight for weight of bale (pounds per bale).
N = Total number of bales produced.
A = Size of area under evaluation (acres).
(2) With respect to a test plot (an area that, due to soils, topography, age, management, locality, and any other factor that affects production, can be expected to produce the same yield as the area being evaluated), the director shall determine whether a test plot is representative of the evaluated area. Test plots collectively shall be at least ten percent (10%) of the area represented, unless the director approves a smaller percentage. No test plot shall be less than one (1) acre. The test plot must be harvested independently of the surrounding area or, if harvested at the same time, records must be maintained by the permittee that provide a measurement of the yield of the test plot that is separate and distinct from the surrounding area. The entire area being evaluated must be in permanent vegetative cover equal to the approved success standard as identified in section 120(c)(3) of this rule. The location of a test plot shall be established after consultation with the director. (3) With respect to yield estimates from clippings, the vegetation growing in one (1) yard squares shall be randomly located in the area under evaluation, clipped, adequately cured under acceptable agronomic practices, and weighed to determine the production from living plants. The vegetation shall be clipped to leave at least one (1) node on the stem to provide for regeneration of foliage. If more than one (1) cutting is necessary to prove the production of the area under evaluation, all additional cuttings must come from the same selected squares unless the entire field is mowed. New squares may be randomly located each year. The production of the area under evaluation (expressed as tons per acre) shall be extrapolated from the clippings obtained from each individual square. For the purposes of section 122 of this rule, the extrapolated production from each square shall be considered an individual observation. The minimum number of observations for the area under evaluation and methods for analysis shall be determined under section 122 of this rule. (d) The following methods may be used to evaluate the production of living plants on cropland for crops other than hay: (1) With respect to a whole field harvest, all vegetation under evaluation shall be harvested and the yield obtained. Each yield shall be adjusted for moisture content and certified as to accuracy. Each yield shall be documented by presenting weigh tickets from a grain elevator or by other means acceptable to the director.(2) With respect to a test plot, as defined under subsection (c)(2), the director shall determine whether a test plot is representative of the evaluated area. The yield shall be adjusted for moisture content. Test plots collectively shall be at least ten percent (10%) of the area to be represented, unless the director approves a smaller area, but not less than one (1) acre. The test plot must be harvested independently of the surrounding area, or, if harvested at the same time, records must be maintained by the permittee which provide a measurement of the yield of the test plot that is separate and distinct from the surrounding area. The entire area being evaluated must be in permanent vegetation or must be used for crop production as provided in the plan of reclamation. The portion in permanent vegetation must have a ground cover equal to the approved success standard as identified in section 120(c)(3) of this rule. The location of a test plot shall be established after consultation with the director.(3) Yield estimates for corn and soybean grain counts shall be counted under methods used by one (1) of the following: (B) University of Illinois.(C) Another institution approved by the director.(e) This method may be used to evaluate stocking or planting on an area developed as fish and wildlife habitat recreation, forest, or shelter belt. Each acceptable tree, shrub, and half-shrub shall be counted that is located within a circle formed by a twenty (20) foot radius centered on a randomly selected point. Each area counted is an individual observation for purposes of section 122 of this rule. The sufficiency of the number of observations shall be determined, and the statistical analysis of the results shall be performed under section 122 of this rule. A tree, shrub, or half-shrub is counted if the species: (1) is designated in the approved reclamation plan;(2) is alive and healthy; and(3) has been in place for at least two (2) growing seasons, with at least eighty percent (80%) of the species counted having been in place for at least three (3) growing seasons.Natural Resources Commission; 312 IAC 25-6-121; filed Jun 21, 2001, 2:53 p.m.: 24 IR 3574, eff Dec 1, 2001; readopted filed May 29, 2007, 9:51 a.m.: 20070613-IR-312070146RFA; readopted filed Sep 19, 2013, 10:12 a.m.: 20131016-IR-312130125RFAReadopted filed 3/26/2019, 3:40 p.m.: 20190424-IR-312190011RFA