Lodgepole Pine Foliar Nutrient Diagnosis and Fertilizer Advisory System

Developed at the Pacific Forestry Centre of the Canadian Forest Service in collabaration with the B.C. Ministry of Forests.

System Design: Dr. A. Thomson, ,  J. Saini

Lodgepole pine forests in British Columbia's interior 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 lodgepole pine 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 "Lodgepole Pine 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:

  1. Administrative information (name, organization, analytical laboratory, foliar sampling date) and pertinent site/stand documentation (latitude, longitude, BEC subzone, site series, elevation, mapsheet, stand age, origin, site index);
  2. Tabulated foliar concentrations of individual nutrients and calculated nutrient ratios;
  3. Comments on input information that may affect foliar nutrient diagnosis (e.g., age and crown position of sampled foliage, stand health);
  4. Complete foliar nutrient diagnoses for all macro- and micro-nutrients for which data are provided; and
  5. 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.

At the bottom of the Data Input Form, scientists from the Pacific Forestry Centre and Ministry of Forests request permission to review the submitted foliar data and associated site/stand information. Documentation of the existence, and geographic distribution, of lodgepole pine nutrient deficiencies in the interior of British Columbia will be improved by combining foliar data from a large number of submissions. The user is not obligated to permit access to the submitted information.

Your comments on the "Lodgepole Pine Foliar Nutrient Diagnosis and Fertilizer Advisory System" are welcomed. Please email or 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.

Data Input Form