ISHS Acta Horticulturae 547: III International Symposium on Rose Research and Cultivation
INORGANIC NITROGEN LOADING AND DISTRIBUTION IN SOIL PROFILES BENEATH ROSE GREENHOUSES |
| Authors: | R.I. Cabrera, R.Y. Evans |
| Keywords: | ammonium, fertilization, ground water pollution, nitrate, Rosa hybrida, root zone, soil solution |
| Abstract:
Inorganic nitrogen (N) loading and distribution were surveyed in soil profiles beneath commercial rose greenhouses. Nitrate-N concentrations, down to a maximum depth of 2 m and across all sampled sites, ranged from 2 to 343 mg kg-1 whereas NH4-N concentrations typically oscillated between 1 and 5 mg kg-1. Soils with clay to clay-loam textures showed a median NO3-N concentration of 70 mg kg-1 in the root zone (upper 30 cm soil layer). These values were lower for sandy soil profiles (median of 14 mg kg-1) but consistently uniform at all sampling depths. Determinations of moisture content for each soil sample allowed the calculation of NO3-N concentrations in the soil solution, with median values of 225 and 188 mg L-1 in the root zone of heavy (clay, clay- loam) and light (sand, sandy loam) soils, respectively. Maximum soil solution NO3-N concentrations exceeded 700 mg L-1 in some heavy textured soils. The estimated total soil N loading on an area basis ranged from 171 to 1470 kg Ha-1 in shallow soil profiles (0-90 cm), and from 529 to 1736 kg Ha-1 in deeper soils (0-180 cm). Sixty percent of the all the surveyed greenhouses showed total N loadings kg Ha-1 below the root zone. These results highlight the pressing need to scrutinize N fertilization programs in commercial rose production and evaluate cultural practices and technologies that minimize environmental impact while sustaining productivity. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
