Metabolite profiling of Komatsuna (Brassica rapa L.) field-grown under different soil organic amendment and fertilization regimes

Among agricultural soil fertility management options, the environmental benefits of organic amendments have recently drawn particular attention. However, little information exists about their effects on crop metabolites or quality. Field plots of Komatsuna (Brassica rapa L. var. perviridis) were planted in a fractional factorial design with the following treatments: soil amendments of cattle manure (0, 2 or 4 kg m−2), wheat straw (0, 0.05 or 0.1 kg m−2), fast release nitrogen (N) (0, 6 or 12 g N m−2 of ammonium sulfate), slow release N (0, 3 or 6 g N m−2 of coated ammonium nitrate), phosphorus (P) [0, 5 or 10 g phosphorus pentoxide (P2O5) m−2 of lime superphosphate] and potassium (K) [0, 6 and 12 g potassium oxide (K2O) m−2 as potassium sulfate]. Metabolite profiling was carried out using a gas chromatograph/mass spectrometer (GC/MS), which yielded 62 and 67 metabolites in the leaves and the petioles, respectively. Metabolite peak areas were subjected to principal component analysis (PCA). The first compo...