The grass seed tag is a legal document, required by law to list specific percentages that inform the buyer exactly what is contained in the package. These regulatory standards ensure transparency in the seed industry. One percentage featured on this label is “Inert Matter,” a key component in determining the overall quality and true value of the seed. Understanding this term is the first step in deciphering the seed analysis tag.
What Exactly Is Inert Matter?
Inert matter is defined as any material in the seed lot that is not a viable seed of the desired crop and is incapable of growth. Measured by weight, it represents the percentage of filler within the bag. Its presence is an unavoidable byproduct of the natural harvesting and cleaning processes used to prepare the seed for market.
The composition of inert matter includes several materials. Common components are broken seed pieces (less than half the size of the original seed), soil, sand, small pebbles, and plant debris such as chaff, straw, hulls, and empty seed casings. While it can sometimes include beneficial seed coatings like fertilizer, a higher percentage means the buyer is paying for material that will not produce a lawn.
The Role of Inert Matter in Seed Purity Analysis
Inert matter plays a central role in the seed’s Purity Analysis, a mathematical calculation that accounts for the entire contents of the package. This analysis is based on the principle that the total contents of the seed lot must equal 100%. The formula is expressed as: Pure Seed % + Inert Matter % + Weed Seed % + Other Crop Seed % = 100%.
A higher percentage of inert matter directly reduces the percentage of Pure Seed, meaning the consumer is purchasing more filler and less of the actual product. This makes it a factor in determining the overall quality and true cost of the seed. To determine the amount of usable product, buyers should look at the Pure Live Seed (PLS) calculation.
Pure Live Seed (PLS)
The PLS percentage calculates the seed that is both pure and capable of germination. It is found by multiplying the Pure Seed percentage by the Germination percentage. Inert matter, which is non-viable by definition, directly lowers the Pure Seed percentage, consequently lowering the PLS. A low PLS indicates that a larger bulk weight of seed must be purchased to achieve the desired seeding rate.
Regulatory Requirements for Labeling Seed Purity
The requirement to list inert matter stems from consumer protection laws designed to ensure market transparency. Seed labeling is federally governed by the Federal Seed Act (FSA), which mandates that all seed shipped across state lines must be truthfully labeled with specific quality information. This federal law is reinforced by corresponding state laws that regulate the sale of seed within their borders.
The legal framework requires that the Purity Analysis, including the percentage of inert matter, be determined by certified seed testing laboratories. These laboratories follow strict, standardized procedures set by organizations like the Association of Official Seed Analysts. This mandatory analysis ensures that the percentages listed on the tag are accurate and verifiable, providing the buyer with assurance.