Effects of Plant Density and Nitrogen Fertilizer on Nitrogen Uptake from Soil and Nitrate Pollution in Potato Tuber

摘要

In order to investigate plant density and nitrogen fertilizer on nitrogen uptake from soil and nitrate pollution in potato tuber cu. Agria, a factorial experiment based on randomized complete block design with three replications was carried out in Ardabil, Iran, in 2006. Factors were nitrogen levels (0, 80, 160 and 200 kg ha~(-1) net nitrogen) and plant densities (5.5, 7.5 and 11 plant m~(-2)). Results showed that the most nitrogen uptake by plant aerial parts and the most nitrate concentration in dry and fresh tuber weight were observed at 200 kg ha~(-1) nitrogen, 11 plant m~(-2) and 200 kg ha~(-1) nitrogen, 5.5 plant m~(-2), respectively. At 160 kg ha~(-1) nitrogen (as equal to 80 kg ha~(-1) nitrogen) and 11 plant m~(-2), the most tuber and yield of tuber were gained. With increasing nitrogen application up to 160 kg ha~(-1), nitrogen uptake by tuber, number of tuber, tuber dry weight and mean tuber weight was increased. 160 and 80 kg ha~(-1) nitrogen jointly with density of 5.5 plant m~(-2), caused the most mean tuber weight per plant. So, utilization of 80 kg ha~(-1) nitrogen to reach highest yield and less nitrate pollution, density of 11 plant m~(-2) to gain seed tuber (because of reduction in tuber weight and size) and density of 7.5 plant m~(-2) for eating usages, are recommended.