SELECTED WATER 

 RESOURCES ABSTRACTS 



INPUT TRANSACTION FORM 



/. Report No. 



4. Title 



Plant Analysis for Nutrient Assay of Natural Waters 



7. Author(s) 



Gerloff, Gerald C. 



9. Organization 



Department of Botany and Institute of Plant Development 

 University of Wisconsin - Madison 



12. Sponsoring Organization 

 15. Supplementary Notes 



Environmental Protection Agency report number 

 EPA-R1-7 3-001, February 1973. 



3. Accession No. 



w 



5. Report Date 



6. 



8. Performing Organization 

 Report No. 



10. Project No. 

 18040 DGI 



11. Contract/ Grant No. 



13. Type of Report and 

 Period Covered 



16. Abstract 



Plant analysis has been developed as a procedure for evaluating nutrient supplies and 

 growth-limiting nutrients for nuisance macrophytes in lakes and streams. Plant 

 analysis is based on establishing in index segments the critical concentration 

 (minimum plant concentration for maximum yield) of each essential nutrient element 

 likely to limit growth of nuisance macrophytes. Critical concentrations for nitrogen, 

 phosphorus, sulfur, calcium, magnesium, potassium, iron, manganese, zinc, boron, and 

 molybdenum were established in appropriate index segments of Elodea occidentalis . The 

 critical copper concentration was estimated. Critical concentrations for several 

 elements also were established in Ceratophyllum demursum u 



To evaluate plant analysis as an assay procedure, index segments of Elodea and 

 Ceratophyllum were routinely collected from Wisconsin lakes, analyzed, and the analyses 

 were compared with the critical concentrations for indications of nutrient deficiency. 

 Nitrogen, phosphorus, calcium, and copper were at or close to critical levels in one 

 or more lakes. Neither nitrogen nor phosphorus seemed to be a general growth- 

 limiting nutrient in the lakes sampled. 



17a. Descriptors 



Nutrient Requirements, Deficient Elements, Mineral Needs, Eutrophication, Aquatic 

 Weeds, Bioassay, Fertility. 



17b. Identifiers 



Wisconsin Lakes 

 Macrophytes 



27c. COWRR Field & Croup 



IS. Availability 



19. Security Class. 

 (Report) 



20. Security Class. 

 (Page) 



21. 



No. of 

 Pages 



Send To: 



22. Price 



WATER RESOURCES SCIENTIFIC INFORMATION CENTER 

 US DEPARTMENT OF THE INTERIOR 

 WASHINGTON, D. C. 20240 



Abstractor Q. C. Gerloff 



I institution University of Wisconsin-Madison 



WRSIC102(REV IUNE1971) 



GP 9 13.261 



