Why do soil tests for micronutrients have limited value?• sampling and soil test methods are less reliable• calibration databases are inadequate• subsoil supply may be sufficientIf soil test levels are high, deficiency is unlikely but low soil test levels are a weak predictor of micronutrient deficiency!
By themselves, extractable nutrient levels (macro or micro) are not informative.Extractable nutrient levels provide an index of nutrient availability that requires calibration using field experiments.
Example of field calibration data for soil test P 100 % yield 50 % yield Soil test P concentration (ppm) http://www.ipm.iastate.edu/ipm/icm/2003/11-17-2003/mehlich3.gif
Understanding soil test calibration ¡Necesito más calor! 5 jalapenos per bowl How would this bowl of chili taste to you?
Have any of you ever had to run a 40 as part of a try-out for a team? How well does your A good 40 time predict your A good coach/scoutfarmer/agronomist knows ability to play the how to put soil put a 40 knows how to test data game? time in context in context