2018 ASHS Annual Conference

Nitrogen (N) use efficiency (NUE) is important in a sustainable vegetable production system and has a significant impact on the system’s nutrient management. Rowcover enhances vegetative growth but N requirement may differ from open field for optimal growth and yield, and N use efficiency. The study was conducted at the Eastern Shore Agricultural Research and Extension Center (AREC), Painter, Virginia Tech, Virginia (longitude -75.82114 and latitude 37.58466). The objective was to determine differences in N requirement and use efficiency in basil under rowcover compared to open field. The experimental design was a split plot with four replications. The main effect was N fertilizer rate (0, 37, 74, 111, 148, and 185 Kg∙ha^-1) and the secondary effect (subplots) was low tunnel covered with spun-bonded row cover (Dewitt, 1oz/sqyd, River Birch Mall, 905 S Kings highway, Sikeston, MO 63801) and no cover. Total fresh weight, and biomass increased with rowcover by 61.0 %, and 73.5% respectively. Fresh weight per plant increased exponentially (R²=0.99) with N fertilization from 832 to 1520g under rowcover, and linearly (R²=0.87) from 555 to 844 g without rowcover. Although NUE increased with rowcover overall and at each fertilization rate, it decreased as the N fertilization rate increased. Height and stem diameter were not different among the fertilization rates. In conclusion, the increase in basil growth and yield due to N fertilization, and the NUE were greater under rowcover than open field.