Search

The objective of this study was to quantify water volume and nutrient content leached during propagation of herbaceous cuttings in commercial greenhouses. Nutrient concentrations in the fertigation solution, substrate, tissue, and leachate were measured between Jan. and Mar. 2006 at eight greenhouse locations in Michigan, Colorado, New Hampshire, and New Jersey. Grower management of the timing and concentration of nutrients applied to vegetatively grown calibrachoa ( Calibrachoa x hybrida) or petunia (Petunia x hybrida) liner trays varied among the eight locations, ranging from 0.5 to 80 mg·L-1 nitrogen (N) in week 1 and from 64 to 158 mg·L-1 N in week 4. Over a 4-week crop period, applied nutrients averaged 4.9 g·m-2 N, 0.8 g·m-2 phosphorus (P), and 5.8 g·m-2 potassium (K), and leached nutrients averaged 1.1 g·m-2 N, 0.3 g·m-2 P, and 1.6 g·m-2 K. Leaching of nutrients and irrigation water was highly variable among locations. Leached water volumes ranged from 4.5 to 46.1 L·m-2 over 4 weeks and contained 0.29 to 1.81 g·m-2 N, 0.11 to 0.45 g·m-2 P, and 0.76 to 2.86 g·m-2 K. The broad range in current commercial fertigation practices, including timing of nutrient supply, concentration of applied fertilizer, and leaching volume, indicate considerable potential to improve efficiency of water and fertilization resources during propagation and reduce runoff. [ABSTRACT FROM AUTHOR]