Tool Box

Crop Nutrient Response Tool

This evaluation tool was designed to assist in interpreting results from on-farm trials; specifically, trials involving multiple rates of any added nutrient. Its main goal is to provide the best possible estimate of "optimum rate" or "most economic rate of N" (MERN) from limited data.

Finding Trends in Soil Test Data

Examine soil test data over time to assess how a fertilization program changes soil test levels.

NuGIS

A Nutrient Use Geographic Information System (NuGIS) for the U.S.

Nutrient Expert®

On-Farm Research

Want to do some field trials of your own? This tutorial provides guidance on designing experiments and provides step-by-step instructions for conducting a statistical analysis in Microsoft Excel.

PKalc

Are phosphorus (P) and potassium (K) nutrient additions keeping up with removal by crops? The spreadsheet PKalc v1.12 is an interactive tool that allows you to keep track of historical nutrient additions and removals for a field or field area.

Rate Reduction Calculator

Estimating Yield Loss from Nutrient Rate Reductions. A common question asked in unfavorable economic times is, “How much yield loss can I expect if I cut my nutrient rates?” The resources provided here offer one approach to coming up with such an estimate.

Seed-Placed Fertilizer Decision Aid

A commonly asked question is "How much fertilizer can I safely apply with the seed?". FertSeedDecisionAid was developed to help answer that question in a reasonably condition-specific manner. This easy to use decision aid is based on regression coefficients (crop stand upon fertilizer rate) that were developed in a laboratory emergence study of common fertilizers and crops and verified with published field studies when they existed. It was developed by South Dakota State University with the support of IPNI.