Nucleic acid detection and quantification method and compositions

A method of measuring the total microbial load of an agricultural species said method comprising

• collecting a sample from an agricultural species;
• storing said sample on a card at room temperature;
• dividing the card into a plurality of smaller sections each comprising a portion of said sample;
• extracting nucleic acids from each of said plurality of section in separate containers to prepare a first, second and third recovered nucleic acid sample;
• and
• analyzing the first recovered nucleic acid sample to detect pathogenic bacterial nucleic acids, analyzing the second recovered nucleic acid sample to detect pathogenic fungal nucleic acids, and analyzing the third recovered nucleic acid sample to detect pathogenic viral nucleic acids, wherein detection of pathogenic bacterial nucleic acids, pathogenic fungal nucleic acids and/or pathogenic viral nucleic acids provides an assessment of the total microbial load of said agricultural species.