Developed at the Pacific Forestry Centre of the Canadian Forest Service in collabaration with the B.C. Ministry of Forests, Lands, Natural Resource Operations and Rural Development.
System Design: Dr. A. Thomson, R. Brockley, J. Saini
Rewritten and updated via R-Shiny: Woongsoon Jang
British Columbia's interior forests are commonly nutrient deficient, and foliar analysis is widely used by forest practitioners to evaluate their nutrient status as part of the stand selection process for large-scale fertilizer operations. Often with help from a forest nutrition specialist, foliar nutrient levels from collected samples are compared with published diagnostic criteria to confirm nitrogen (N) deficiencies, and to infer whether other nutrients will either limit growth response or become growth-limiting after N is added. Analytical results are often used to prescribe fertilizer formulations to correct inferred nutrient deficiencies.
The interpretation of foliar nutrient data is not straightforward, even when interpretative criteria are available. Foliar nutrient interpretations are subject to serious shortcomings when foliage is collected using non-standardized methods, and when data are reviewed without knowledge or consideration of site and stand factors that may reduce the reliability of interpretations. Foliar analysis results can also be affected by differences in analytical methodology used for the extraction and determination of foliar nutrients. Finally, tacit knowledge, accumulated through years of foliar analysis and fertilization research experience, can be an important part of diagnosing probable nutrient deficiencies and formulating fertilizer prescriptions. Forest practitioners charged with the task of collecting and interpreting foliar nutrient data often lack this experience.
This interactive, knowledge based system has been developed specifically for forest practitioners to facilitate the reliable diagnosis of British Columbia's interior species foliar nutrient status and the formulation of appropriate fertilizer prescriptions for large-scale fertilizer operations. Links are provided to updated Foliar Sampling Guidelines and Nutrient Interpretative Criteria for Lodgepole Pine and common and noticeable Visual Deficiency Symptoms for individual nutrients.
A web-based system is accessible to most personal computers, and can be easily updated to broaden its scientific and practical applications. Users of the "Foliar Nutrient Diagnosis and Fertilizer Advisory System" are prompted for various input information, some of which is used for diagnostic purposes, and some of which is simply re-formatted and printed to provide complete documentation of the foliar sampling project. The system uses the input data to generate five types of output:
- Administrative information (name, organization, analytical laboratory, foliar sampling date) and pertinent site/stand documentation (species, latitude, longitude, BEC subzone, site series, elevation, mapsheet, stand age, origin, site index);
- Tabulated foliar concentrations of individual nutrients and calculated nutrient ratios;
- Comments on input information that may affect foliar nutrient diagnosis (e.g., age and crown position of sampled foliage, stand health);
- Complete foliar nutrient diagnoses for all macro- and micro-nutrients for which data are provided; and
- Recommended fertilizer prescription to correct inferred nutrient deficiencies.
The system uses functions developed from inter-laboratory comparisons to automatically adjust foliar levels of some nutrients to "normalized" values from which diagnoses and fertilizer prescriptions are made. Normalization is necessary for consistent application of diagnostic and prescriptive rules. No inferences should be drawn from the normalization requirement regarding the quality or integrity of the submitted foliar data.
Your comments on the "Foliar Nutrient Diagnosis and Fertilizer Advisory System" are welcomed. Please email Woongsoon Jang regarding comments.
Funding for this extension product was provided by Forest Renewal BC.
The use of trade, firm, or corporation names is for the information and convenience of the user. Such use does not constitute an official endorsement or approval, by the Government of Canada, the Government of British Columbia, or Forest Renewal BC, of any product or service to the exclusion of others that may also be suitable.
Brockley, R.P. 2001. Foliar sampling guidelines and nutrient interpretative criteria for lodgepole pine. B.C. Min. For., Research Branch, Victoria. Extension Note 52.
Brockley, R.P. 2001. Scientists develop "expert" system for diagnosing the foliar nutirent status of lodgepole pine. LINK Newsletter 3(3) 18 p.
Brockley, R.P. 2012. New tools for interpreting foliar nutrient status. Presentation for Fertilization Working Group.
Thomson, A, R. Brockley, and J. Saini. 2001. Lodgepole pine foliar nutrient diagnosis and fertilizer advisory system. Online. Canadian Forest Service, Pacific Forestry Centre, Victoria.
Thomson, A, R. and Taylor C.M.A. 1990. An expert system for diagnosis and treatment of nutrient deficiencies of Sitka spruce in Great Britain. AI Applications in Natural Resource Management 4(1): 44-52.