Gross N transformations and plant N use efficiency in intensive vegetable production soils

Long-term application of high doses of N fertilizer to achieve high yields has led to a significant accumulation of soil N (largely in the form of NO3−) in greenhouse vegetable production (GVP). At present, it is not clear how efficiently vegetables can use the NO3− accumulated in soil and from which source the N taken up by vegetables in GVP originates. In this study, three greenhouse soils with various degrees of soil NO3− accumulation (N1