Nutrient Expert^® is an easy-to-use, interactive, and computer-based decision support tool that can rapidly provide nutrient recommendations for an individual farmer field in the presence or absence of soil testing data.

Nutrient Expert^® is Based on Principles of Site-specific Nutrient Management

Nutrient Expert^® (NE) is a nutrient decision support software that uses the principles of site-specific nutrient management (SSNM)^1,2 and enables farm advisors to develop fertilizer recommendations tailored to a specific field or growing environment. NE takes into account the most important factors affecting nutrient management recommendations and uses a systematic approach of capturing information, which is important for developing a location-specific recommendation. Yet, NE does not require lot of data or very detailed information, as is the case with many sophisticated nutrient decision support tools, which could overwhelm the user. As a computer-based decision support tool, NE combines all the steps and guidelines in SSNM into a simple software tailored for farm advisors, especially the not-so-technical users such as extension agents and industry agronomists in developing countries. In such countries, many farm advisors from the both public and private sector do not have the data and facilities needed to run sophisticated models. Nutrient Expert^® allows users to draw required information from their own experience, farmers’ knowledge of the local region and farmers’ practices. NE can use experimental data but it can also estimate the required SSNM parameters using existing site information. The parameters needed in SSNM are usually measured in nutrient omission trials conducted in farmers’ fields, which require at least one crop season. With NE, parameters can be estimated using proxy information, which allows farm advisors to develop fertilizer guidelines for a location without data from field trials.

The algorithm for calculating fertilizer requirements in NE is determined from a set of on-farm trial data using SSNM guidelines. In SSNM, the N, P, and K requirements are based on the relationships between balanced uptake of nutrients at harvest and grain yield^3,4,5. This relationship is called internal nutrient efficiency and is predicted using the quantitative evaluation of the fertility of tropical soils (QUEFTS) model⁶. The fertilizer requirement for a field or location is estimated from the expected yield response to each fertilizer nutrient, which is the difference between attainable yield and nutrient-limited yield. Nutrient-limited yield is determined from nutrient omission trials in farmers’ fields, i.e., when a nutrient of interest is omitted while all other nutrients are supplied in ample amounts. Attainable yield at a location is the yield obtained in a typical year using best management practices without any deficiency of nutrients. The amount of nutrients taken up by a crop is directly related to its yield so that the attainable yield indicates the total nutrient requirement and nutrient-limited yield indicates the indigenous nutrient supply⁷. The yield response indicates nutrient deficit, which must be supplied by fertilizers. Nutrient Expert^® also follows SSNM guidelines for fertilizer application and split dressings, which consider the nutrient demand of a crop at critical growth stages².

This article was adapted from: Pampolino M.F., C. Witt, J.M. Pasuquin, A. Johnston and M.J. Fisher. 2012. Computers Electron. Agri. 88:103-110.

Software License Agreement

Please read the terms and conditions of this license agreement carefully before downloading or using the software. By accessing or using this software, you agree to these terms and conditions.

TERMS AND CONDITIONS OF USE

© 2009 by the International Plant Nutrition Institute. All rights reserved.

DISCLAIMER

THE INTERNATIONAL PLANT NUTRITION INSTITUTE (IPNI) AND THE SOFTWARE DO NOT ENDORSE OR PROMOTE SPECIFIC FERTILIZERS AND DO NOT GUARANTEE THE ACCURACY OF AN ANALYSIS LABELED ON COMMERCIAL FERTILIZERS. THE SOFTWARE ASSUMES THAT THE N, P2O5, AND K2O ANALYSIS LABELED ON A BAG OF ORGANIC OR INORGANIC FERTILIZER ACCURATELY REFLECTS THE CONTENT OF PLANT NUTRIENTS IN THE FERTILIZER. IN ADDITION TO NUTRIENTS, MANY FACTORS (E.G. CLIMATE, CROP CARE, WATER MANAGEMENT) AFFECT MAIZE YIELD. IPNI AND THE SOFTWARE DO NOT GUARANTEE A TARGETED MAIZE YIELD WILL BE ATTAINED WITH THE PROVIDED NUTRIENT MANAGEMENT GUIDELINES.

LIMITS OF LIABILITY

UNDER NO CIRCUMSTANCES AND UNDER NO LEGAL THEORY, WHETHER TORT, CONTRACT, OR OTHERWISE, SHALL IPNI OR ANY OF ITS AFFILIATES, OFFICERS, EMPLOYEES, OR OTHER REPRESENTATIVES BE LIABLE TO YOU OR ANY OTHER PERSON FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF ANY CHARACTER INCLUDING, WITHOUT LIMITATION, DAMAGES OR LOSS OF GOODWILL, WORK STOPPAGE, COMPUTER FAILURE OR MALFUNCTION, OR ANY AND ALL OTHER COMMERCIAL DAMAGES OR LOSSES, SPECIFICALLY INCLUDING DAMAGES TO CROPS AND SOIL RESULTING FROM THE APPLICATION OF THE SOFTWARE, OR FOR ANY DAMAGES EVEN IF IPNI SHALL HAVE BEEN INFORMED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY. THIS LIMITATION OF LIABILITY SHALL NOT APPLY TO LIABILITY FOR DEATH OR PERSONAL INJURY TO THE EXTENT APPLICABLE LAW PROHIBITS SUCH LIMITATION.