La. Admin. Code tit. 43 § XV-5424

Current through Register Vol. 50, No. 11, November 20, 2024

Section XV-5424 - Revegetation: Standards for Success-Post-Mining Land Use of Pastureland

A. Introduction

1. This Section describes the criteria and procedures for determining ground cover and production success for areas being restored to pastureland.

2. Pursuant to §5423, ground cover and production success on pastureland must be determined on the basis of the following conditions:

a. general revegetation requirements of the approved permit;

b. ground cover density; and

c. production.

3. The permittee is responsible for determining and measuring ground cover and production and submitting this data to the commissioner for evaluation. Procedures for making these determinations are described below.

B. Success Standards and Measurement Frequency

1. Ground Cover

a. Ground cover shall be considered acceptable if it is at least 90 percent of the approved success standard at a 90 percent statistical confidence level for any two of the last four years of the five-year responsibility period. The success standard for ground cover shall be 90 percent.

i. Ground cover must be measured over each noncontiguous area that is proposed for release. The aggregate of areas with less than 90 percent ground cover must not exceed 5 percent of the release area. These areas must not be larger than 1 acre and must be completely surrounded by desirable vegetation that has a ground cover of 90 percent. Areas void of desirable vegetation may not be larger than 1/4 acre and must be surrounded by desirable vegetation that has a ground cover of 90 percent. Refer to sampling technique for ground cover in §5424. C.2 a

b. Ground cover shall consist of the species mixture approved in the original permit or an approved acceptable species mixture as recommended by the USDA/Natural Resources Conservation Service (NRCS) for use in that area. No more than 15 percent of the stand can be approved species not listed in the permit.

c. The sampling techniques for measuring success shall use a 90 percent statistical confidence interval (i.e., one-sided test with a 0.10 alpha error). Whenever ground cover is equal to or exceeds the success standard, the statistical confidence interval test does not have to be determined.

d. Ground cover success and forage production success need not be met during the same year.

e. Ground cover shall be sampled once per year during any two of the last four years of the five-year responsibility period to verify cover data.

2. Forage Production

a. The success standard for production of hay on pastureland shall be 90 percent of an approved reference area, if a reference area is established, or 90 percent of the estimated yield found in the Soil Conservation Service (now Natural Resources Conservation Service (NRCS)) parish soil survey. The estimated yields are those expected under a high level of management and were determined by the NRCS based on records of farmers, conservationists and extension agents.

b. Production shall be sampled for at least two separate years. Any two of the last four years of the five-year responsibility period may be selected.

3. Reference Area Requirements

a. Reference areas must be representative of soils, slope, aspect, and vegetation in the premined permit area. However, in cases where differences exist because of mixing of several soil series on the reclaimed area or unavailability of a reference area as herein described, yields must be adjusted.

b. Reference area pastureland must be under the same management as pastureland in the reclaimed area. This means that it must:

i. consist of similar plant species and diversity as approved in the permit;

ii. be currently managed under the same land use designation as the proposed mined release area;

iii. consist of soils in the same land capability class;

iv. be located in the general vicinity of the mined test area to minimize the impact of differing weather;

v. use the same fertilizer and pest management techniques;

vi. use fertilizer rates based on the same yield goal;

vii. be mowed at the same time to the same height as the reclaimed area;

viii. use identical harvest dates and plant populations; and

ix. use any other commonly used management techniques not listed above such as adequate weed and insect control, provided the pastureland area and the reference plot are treated identically.

c. Reference areas shall consist of a single plot (whole plot) at least 4 acres in size. Either statistically adequate subsampling or whole plot harvesting may be used to determine yields.

d. Reference plot forage yields must be at a level that is reasonably comparable to the parish average for the given crop. Reference plot yields that are less than 80 percent of the parish average are highly suspect and may be rejected.

e. Reference areas may be located on undisturbed acreage within permitted areas. If not so located, the permittee must obtain from the landowner(s) a written agreement allowing use of the property as a reference area and allowing right of entry for regulatory personnel.

f. When release areas and reference plots fall on different soil series, adjustments must be made to compensate for the productivity difference.

C. Sampling Procedures

1. Random Sampling

a. To assure that the samples truly represent the vegetative characteristics of the whole release or reference area, the permittee must use methods that will provide:

i. a random selection of sampling sites;

ii. a sampling technique unaffected by the sampler's preference; and

iii. sufficient samples to represent the true mean of the vegetation characteristics.

b. Sampling points shall be randomly located by using a grid overlay on a map of the release or reference area and by choosing horizontal and vertical coordinates. Each sample point must fall within the release or reference area boundaries and be within an area having the vegetative cover type being measured. Additionally, at least one ground cover sample point must be measured in each noncontiguous unit, if the release area does not consist of a single unit.

c. The permittee shall notify the office 10 days prior to conducting sampling or other harvesting operations to allow regulatory personnel an opportunity to monitor the sampling procedures.

2. Sampling Techniques

a. Ground Cover. There are several approved methods for measuring ground cover. As stated at §5423. A 1, these are: pin method, point frame method and line intercept method. The first contact, or "hit," of vegetation shall be classified by species as acceptable or unacceptable as follows.

Acceptable	Unacceptable
Vegetation approved in permit	Vegetation not approved in permit
Dead vegetation or litter from acceptable species	Rock or bare ground
Acceptable-not approved in permit

i. Pin Method. In the pin method, a pinpoint is lowered to the ground. If vegetation is encountered, a hit is recorded. If bare ground is encountered, a miss is recorded. Sample locations are distributed randomly throughout the area to be measured. Percentage of cover is the number of hits divided by the total number of points sampled. Each randomly placed pin is considered one sample unit. An acceptable type of pin method would include recording each pin contact at one-foot intervals along a 100-foot tape. Each randomly placed 100-foot tape would be considered one sample unit.

ii. Point Frame Method. In the point frame method, a group of pinpoints is lowered to the ground. If vegetation is encountered, a hit is recorded. If bare ground is encountered, a miss is recorded. Sample locations are distributed randomly throughout the area to be measured. Percentage of cover is the number of hits divided by the total number of points sampled. Each randomly placed frame is considered one sample unit.

iii. Line Intercept Method. The sampling unit is a tape at least 100 feet long that is stretched from a random starting point in a randomly selected direction. The procedure consists of recording the length of tape underlain by vegetation, then dividing by the total length of tape to obtain the percentage of cover. Each randomly located tape is considered one sampling unit.

b. Productivity

i. When evaluating productivity, two components that may potentially influence the end results of production yields are time of harvest and moisture content.

(a). Time of Harvest. Herbaceous species must be harvested at times and frequencies appropriate to the plant species (i.e., cool-season species should be sampled in the winter or spring; warm-season species should be sampled in the summer or fall). Sampling should be timed to coincide with seed ripeness or the mature stage of the target vegetative species. Plant communities that are comprised of both cool- and warm-season species should be sampled when the overall plant community production is at a peak. If an area has not had herbaceous biomass removed (i.e., mowing, baling, grazing) since the last sampling, then sampling must not be conducted until the vegetation is removed and regrowth has taken place.

(b). Moisture Content. The moisture content of harvested herbaceous biomass and other vegetative components must be standardized, in order to eliminate weight variations due to moisture content. The weight of harvested vegetation is to be standardized by oven-drying at 60° C for 24 hours or until the weight stabilizes.

ii. Productivity can be evaluated by hand-harvesting or with mechanized agricultural implements. Productivity measurements must be obtained during the growing season of the primary vegetation species. Productivity is estimated from only the current season's growth. There are two methods that can be used to evaluate production: using sampling frames for harvesting plots or whole-field harvests.

(a). Sampling Frames. A sampling frame shall be an enclosure, of known dimension appropriate for sampling pasture lands, capable of enclosing the sample location. A sample location shall be established at each of the randomly chosen sites, such that the center of the sampling frame is the random point. The permittee shall clip the biomass 2 inches above ground level within the frame. The biomass to be clipped shall be from all plant species growth whose base lies within the sampling frame. This biomass shall then be weighed and recorded. As each frame is clipped and weighed, the biomass shall be put into a bag for oven drying. Samples shall be oven-dried to a constant weight and reweighed to determine dried weight. All data collected from the clippings within the sampling frame shall be recorded and analyzed.

(b). Whole Area Harvesting. If whole release area harvesting is chosen as the method for data collection, the entire area shall be harvested and the data recorded and analyzed.

iii. If truckloads of bales are weighed for hay production when a whole area is harvested, at least three truckloads from each 100 acres are weighed. Each truckload should have at least three large round bales or 20 square bales. A sample will consist of the average bale weight per truckload. A statistically adequate sample size must be obtained. Multiply the number of hay bales per area by the average bale weight to obtain total production for that area. Total production is then compared to 90 percent of the reference or target yield, using a 90 percent or greater statistical confidence level.

iv. If performing statistical comparisons for hay production when a whole field is harvested, the weights of either 10 percent or 15 bales, whichever is greater, are converted to pounds per acre (lbs/ac) by taking their average weight and multiplying that figure by the total number of bales, divided by the number of acres harvested. Total production is then compared to 90 percent of the reference or target yield, using a 90 percent or greater statistical confidence level.

v. To determine which bales to weigh, randomly select a number from one to ten then count and weigh every tenth bale thereafter until the minimum number or 10 percent of the bales have been weighed. The first and last bale of any noncontiguous field or site should not be weighed. The bales shall be counted, but if the random number falls on either of the two bales mentioned, either advance one bale or select the bale immediately previous to the last bale produced.

3. Sample Adequacy

a. Ground Cover Data

i. Data shall be collected using a multi-staged sampling procedure. During the first stage, an initial minimum number of samples is taken. Using this initial group and applying the formula below, determine the actual number of samples needed.

Click Here To View Image

where:

n = minimum number of samples needed;

t² = squared t-value from the T-Table;

s² = initial estimate of the variance of the release (or reference) area; and

(0.1x)² = the level of accuracy expressed as 10 percent of the average cover (note that this term is squared).

ii. If the formula reveals that the required number of samples is equal to or less than the initial minimum number, the initial sampling will satisfy the sampling requirements. If the number of samples needed is greater than the initial minimum number, additional samples must be taken (Stage Two Sampling), as specified by the formula, and n recalculated. This process shall be repeated until sample adequacy is met.

b. Productivity Data

Click Here To View Image

(the variance (s ²) must be based on oven dry weight)

where:

n = minimum number of samples needed;

t² = squared t-value from the T-Table;

s² = initial estimate of the variance of the release (or reference) area; and

(0.1x)² = the level of accuracy expressed as 10 percent of the average weight (note that this term is squared).

ii. If the formula reveals that the required number of samples have been taken, the initial sampling will satisfy the sampling requirements. If a greater number of samples is needed, additional samples must be taken (Stage Two Sampling), as specified by the formula, and n recalculated. This process shall be repeated until sample adequacy is met.

D. Data Submission and Analysis

1. If the data shows that revegetation success has been met, the permittee shall submit the data to the commissioner for review. Ground cover or production for the release area will be considered successful when it has been measured with an acceptable method, has achieved sample adequacy, and where the average ground cover or production value is equal to or greater than the success standard.

2. When the data indicates that the average ground cover and average forage production was insufficient, but close to the standards, the permittee may submit the data to the commissioner to determine if the production was acceptable when statistically compared to the standards using a t-test at a 90-percent statistical confidence interval.

3. Raw yield data from reclaimed areas and raw data from reference areas must first be oven dried to remove moisture, then adjusted by the parish soil survey average yields before statistical comparisons can be made.

E. Maps

1. When a proposed reclamation Phase III release is submitted to the office, it must be accompanied by maps showing:

a. the location of the area covered by the proposed release;

b. the location of reference plots; and

c. all permit boundaries.

2. When data from a previously approved plan is submitted to the office, it must be accompanied by maps showing:

a. the location of and reference plots;

b. the location of each sample point;

c. the area covered by the sampling; and

d. all permit boundaries.

F. Mitigation Plan

1. Ground cover and forage productivity must equal or exceed the standards for reclamation Phase III liability release for at least two sampling years during the second through the fifth years following completion of the last augmented seeding. If productivity is not achieved by these dates, the permittee must submit a mitigation plan to the commissioner that includes the following:

a. a statement outlining the problem;

b. a discussion of what practices, beyond normal farming practices, the operator intends to use to enable the area to finally meet the release standards; and

c. a new Phase III release proposal.

2. If renovation, soil substitution or any other practice that constitutes augmentation is employed, the five-year responsibility period shall restart after the mitigation plan is approved and the practices are completed.

La. Admin. Code tit. 43, § XV-5424

Promulgated by the Department of Natural Resources, Office of Conservation, LR 29:1497 (August 2003).

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:901-932.