Accumulation differences of nitrate in main vegetables in Zhejiang province and its affecting factors

The results of monitoring nitrate concentrations in 17 vegetables in 8 cities in Zhejiang showed that the nitrate concentrations in vegetable samples reaching the national standards in 2003 and 2004 were 45.5% and 54.2%,respectively.Green leaf vegetable was one containing high nitrate.Leaf vegetables contained much higher nitrate than that root and stem vegetables.The accumulation of nitrate in vegetables was closely related to soil total N and N rate applied in late stage(before harvesting).It was suggested that proper selection of vegetable species and controlling N supply in late stage could effectively control nitrate accumulation in vegetables.