Influence of Fertilizer Source and Irrigation Regimen on Containerized Production of Coleus (Plectranthus scutellarioides (L.) Codd) 'Solar Sunrise' and Management of Bermudagrass (Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy) 'Tifway'

Fertilizer nutrient losses through leachate and runoff from excessive irrigation in nursery container production and turfgrass management can be high and have negative environmental impacts. The objective of this research was to examine the influence of fertilizer source and irrigation regimen on nutrient losses during nursery container production and turfgrass management. During the container production of coleus (Plectranthus scutellarioides (L.) Codd) 'Solar Sunrise', four fertilizer treatments: an unfertilized control; a controlled-release (CRF); a water-soluble (WSF); and a combination of 10% WSF and 90% CRF, were incorporated into a pine bark substrate at 0.30 kg N and P·m-3 in 3.7-L containers and irrigated at 1.9 cm·day-1 or 3.8 cm·day-1 under greenhouse conditions for 56 days. Plant quality was measured every 14 days and total biomass was measured every 28 days. Leachate was collected weekly and analyzed for N (NO3- and NH4+) and P (dissolved total P, DTP). Plant growth was similar across CRF, combination (WSF and CRF), and WSF treatments and irrigation regimens. Fertilizer source did affect nutrient leaching losses. Coleus fertilized with WSF resulted in higher total N (NO3--N + NH4+-N) and DTP losses compared to coleus fertilized with CRF or combination fertilizer regardless of irrigation regimen. Decreasing irrigation regimen for WSF treatment resulted in a reduction of total N losses, but did not reduce total DTP losses. Three fertilizer treatments: an unfertilized control; a controlled-release (CRF); and a water-soluble fertilizer (WSF), were applied at 97.6 kg N and P· ha-1 to bermudagrass (Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy) 'Tifway’ established in runoff trays. Plant growth was measured every 14 days. Rainfall simulation events were held every 4 weeks for 12 weeks during which water samples were collected following 30 minutes of simulated rainfall output at 0.12 cm·min-1 and analyzed for N (NO3- + NH4+) and DTP. There were no differences in bermudagrass plant growth between WSF and CRF treatments. WSF treatment resulted in highest total N and DTP losses. Nutrient leaching can be reduced without sacrificing plant growth during coleus container production and bermudagrass management through the application of CRF.