An apparatus configured for dispensing nutrients includes a dispensing system configured for dispensing the nutrients for a particular plant hybrid or plant variety and a variable rate controller operatively connected to the dispensing system and configured to control dispensement of the nutrients from the dispensing system. The variable rate controller may be programmed to use a plant growth response function for the particular plant hybrid or plant variety and adjust the dispensement of the nutrients from the dispensing system based on the plant growth response function and further programmed to use a pre-determined plug value for the particular plant hybrid or plant variety for initial calibration.
