Influence of different nitrogen sources and levels on ion content of cabbage (Brassica oleracea var. capitate)


Turan M., Sevimli F.

NEW ZEALAND JOURNAL OF CROP AND HORTICULTURAL SCIENCE, vol.33, no.3, pp.241-249, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 33 Issue: 3
  • Publication Date: 2005
  • Doi Number: 10.1080/01140671.2005.9514356
  • Journal Name: NEW ZEALAND JOURNAL OF CROP AND HORTICULTURAL SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.241-249
  • Keywords: nitrogen fertilisation, organic acid, nitrate content, cabbage, yield, INTRACELLULAR PH REGULATION, AMINO-ACIDS, NITRATE ASSIMILATION, CHINESE-CABBAGE, OXALATE, GROWTH, PLANTS, SHOOT, NUTRITION, AMMONIUM
  • Ataturk University Affiliated: No

Abstract

The objective of this study was to determine the effects of different nitrogen (N) sources and levels on ion content in cabbage (Brassica oleracea var. capitate 'Yalova-1'). In the process Of ion uptake by plants, electro-neutrality is maintained both by the plant and the nutrient medium in which the plant is grown. N fertiliser not only affects yield but also the quality of the plant. Nitrates convert to nitrite in plant tissues which may cause health problems in infants and also form carcinogenic substances. Higher doses of nitrites change haemoglobin to methaemoglobin and this inhibits the transport of blood oxygen in the human body. Increased rates of N fertilisers also cause the accumulation of oxalic acid in vegetables. Oxalic acid causes acute toxicity if taken with calcium (Ca) and this forms stones in the kidney. Cabbage plants were grown in field conditions with five N fertiliser types, four doses and three replications. The treatments of N consisted of: no added fertiliser; 100, 200, and 400 kg N ha(-1) as potassium nitrate, ammonium nitrate, urea, ammonium sulphate, and farmyard manure. The results demonstrate that plant head weight was generally greater when mineral fertiliser rather than organic fertiliser was supplied to plants. In the 400 kg N ha(-1) treatment as potassium nitrate, ammonium nitrate, ammonium sulphate, urea, and farmland manure application, plant yields were 66%, 61%,40%,49%,and 44% higher than with no added fertiliser, respectively. When the data were subjected to multiple regression analysis, effects of ammonium nitrate fertiliser application at 342 kg N ha(-1) on plant yields (3333 g plant(-1)) were higher than that of other fertiliser applications. With increasing NO3- nutrition, the bulk of anion charge appeared as organic anion accumulation in the plants. The increase in organic anion accumulation was paralleled by an increase in cation concentration (K+ Ca+2, Mg+2, Na+). Total inorganic anion levels (NO3-, SO42-, H2PO4-, Cl-) were relatively constant. The effects of increasing NO3- nutrition in stimulating organic anion accumulation such as glutamate, malate, and oxalate were far greater than ammonium and the other nutrient forms. Nitrate content of plants increased with the increasing N application, especially with nitrate fertiliser. The increases observed in the plant were highest in the plots with potassium nitrate applied and lowest in plots with no added fertiliser treatment. The results also indicated that farmyard manure was Much more suitable than mineral fertilisers for plant quality according to lower total N, nitrate, and oxalic acid contents of cabbage plants. However, ammonium sulphate application at the rate of 250 kg N ha(-1) was the Most Suitable fertiliser application rate for plant quality according to lower risk yields of plants (2650 g plant(-1)) for human nutrition.