A multi-product applicating system, seed planting system and control are provided for the dispensing of liquid or granular products in pre-selected amounts and planting seeds at pre-selected depths and frequencies. Three or more separate products can be dispensed simultaneously and constant control and...http://www.google.fr/patents/US5931882?utm_source=gb-gplus-shareBrevet US5931882 - Combination grid recipe and depth control system
