Illinois Administrative Code › Title 35 - ENVIRONMENTAL PROTECTION › Part 391 - DESIGN CRITERIA FOR SLUDGE APPLICATION ON LAND › Subpart E - SAMPLE COLLECTION AND ANALYSIS › Section 391.530 - Plant Tissue Sampling and Analyses

Current through Register Vol. 48, No. 28, July 12, 2024
a) Plant tissue monitoring programs are
				sensitive to the care and standard techniques used in the sample collection,
				handling and analysis. This section presents recommended guidelines intended to
				minimize error in a plant tissue monitoring program. It is recommended that a
				professional agronomist or crop scientist be consulted when developing such a
				program.
b) Plant tissue sampling
				should include as many samples as possible. The same part of each plant should
				be sampled and samples should not include dead tissue. Usually it is adequate
				to sample only the portion of the plant that will be harvested. Collection of
				samples is not recommended when plants are under severe moisture or temperature
				stress. Leaf analysis for grain crops should be done on samples collected prior
				to pollination, especially if macro- and/or micro-nutrients will be
				analyzed.
c) Sample should be
				washed in a 0.1 to 0.3 % detergent solution followed by 2 or 3 rinsings in
				deionized water. Washing should be performed quickly to avoid leaching water
				soluble constituents. Most household detergents are suitable for washing plant
				tissues.
d) Plant tissue samples
				should be dried as rapidly as possible after collection. Place the tissue
				samples in a clean muslin bag or tray and place inside a forced-draft oven at
				65°C for 48 hours.
e) Plant
				tissues samples are normally ground after drying. Mechanical grinding mills are
				preferred and careful consideration should be given to sample contamination
				especially when micro-nutrient elements are to be determined. The recommended
				technique is to grind the sample to about 200 mesh in an all-agate mechanical
				ball mill. After grinding place the powdered plant tissue sample in a clean
				bottle and dry for an additional 24 hours at 65°C to remove moisture picked
				up during grinding.
f) After
				grinding and the second drying, a subsample can be weighed for analysis or the
				bottle sealed and stored under refrigerated conditions until the analysis can
				be performed.
g) It is recommended
				that samples be stored in sealed polyethylene bags in a refrigerator at
				-5°C until they can be washed and dried. Dried and ground plant tissue
				samples should not be stored on the shelf longer than 60 days prior to
				analysis. However, dried and ground samples can be stored indefinitely in a
				sterilized, sealed bottle in a refrigerator at -5°C.
h) There are numerous methods available for
				the analysis of plant tissue samples. Most procedures involve wet or dry ashing
				or the use of an extraction procedure followed by element analysis typically by
				atomic absorption, flame emission, or direct-reading emission spectroscopy. Wet
				ashing by the use of nitric and/or sulfuric acid is preferred to dry ashing in
				an oven to minimize volatile losses of metals. Boron can be determined only by
				dry ashing become because this element is volatilized during wet
				ashing.
i) For further information
				on this subject the Agency suggests the following reference: Soil Testing and
				Plant Analysis, Revised Edition, (1973). Edited by Leo M. Walsh and James D.
				Beaton, Soil Science Society of American, Inc., 677 South Segoe Road, Madison,
				Wisconsin 53711.