Sugarbeet response to nitrogen under sprinkler and furrow irrigation.

摘要

N management is important in the production of a high yielding, high quality sugar beet crop. Too little N can limit yield, whereas too much can reduce quality, cause surface and ground water contamination and increase input costs. Sugar beets grown under sprinkler irrigation have been shown to have higher levels of impurities and lower extraction than those grown under furrow irrigation. In this study, sugar beet response to varying rates of N under both types of irrigation was investigated. Plots with varying rates of N application were set up under a linear overhead sprinkler irrigation system and under furrow irrigation. The 2 irrigation sites were located in the same field and were separated by 15 sugar beet rows (9 m). Sugar beets grown under furrow irrigation had the highest sucrose yield with available N levels of 141-197 kg/ha. Under furrow irrigation, Na and amino-N increased as applied N increased. This resulted in increased sucrose loss to molasses as applied N increased, whilst percentage extraction decreased. Sugar beets grown under sprinkler irrigation had the highest sucrose yield at available N levels of 112-169 kg/ha. When compared with sugar beets grown with no applied N, sprinkler irrigated sugar beets showed increased levels of impurities and sucrose loss to molasses at all rates of N application.