title: [Effects of different nitrogen forms and their ratios on broccoli yield, quality, and nutrient absorption].
abstract: A field experiment was conducted to study the effects of different nitrogen forms ((NH2)2CO-N, NO(3-)-N, NH(4+)-N, and NO(3-)-NH4+) and their ratios on the yield formation, quality, and nutrient (N, P, and K) absorption of broccoli (Brassica oleracea). Fertilization with NO(3-)-N increased the accumulation of nitrate and soluble sugars in ball flower. When the NO(3-)-N: NH(4+)-N ratio was ranged from 3:7 to 5:5 and from 5:5 to 7:3, respectively, the accumulation of nitrate in the ball flower was reduced, while the soluble sugars content was promoted. Fertilization with (NH2)2CO-N and NH(4+)-N was conducive to the improvement of Vc content in the ball flower. N fertilization increased the accumulation of N, P, and K in plants, with the highest contents of N, P, and K observed at rosette stage. Throughout the entire growth period, NH(4+)-N fertilization improved the plant N content, whereas NO(3-)-N fertilization improved the plant K content. At different growth stages, the effects of different N sources on plant P content varied. As compared with applying single N forms, the NO(3-)-N:NH(4+)-N ratio ranged from 3:7 to 5:5 could improve the yield significantly. It was suggested that a combined application of NO(3-)-N and NH(4+)-N with an appropriate ratio could improve the productivity, quality, and economic return of broccoli.
authors.affiliation: College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. liuzf@st.gsau.edu.cn
authors.forename: Zhao-Fan
authors.initials: ZF
authors.lastname: Liu
authors.forename: Guo-Bin
authors.initials: GB
authors.lastname: Zhang
authors.forename: Ji-Hua
authors.initials: JH
authors.lastname: Yu
authors.forename: Hai-Xing
authors.initials: HX
authors.lastname: Yang
authors.forename: Gui-Ying
authors.initials: GY
authors.lastname: Shi
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Ma
authors.forename: Jie
authors.initials: J
authors.lastname: Li
mesh_terms: D018533:Biomass; D001937:Brassica / Q000254:growth & development* / Q000378:metabolism; D002681:China; D005308:Fertilizers; D009584:Nitrogen / Q000737:chemistry* / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011786:Quality Control
chemical_list: D005308:Fertilizers; D010758:Phosphorus; D009584:Nitrogen; D011188:Potassium