pubs.acs.org/JAFC Published on Web 01/20/2010 © 2010 American Chemical Society 1788 J. Agric. Food Chem. 2010, 58, 1788–1793 DOI:10.1021/jf903416a Influence of Organic and Conventional Growing Conditions on the Nutrient Contents of White Head Cabbage (Brassica oleracea var. capitata) during Two Successive Seasons SEDAT CITAK AND SAHRIYE SONMEZ* Akdeniz University, Faculty of Agriculture, Soil Science Department, Antalya, Turkey Organically and conventionally grown white head cabbage (Brassica oleracea var. capitata) plants were cultivated during two successive seasons (spring and autumn) to evaluate the effects of the applications on the nutrient content of the edible part of cabbage plants. Seventeen different organic applications containing farmyard manure (FM), chicken manure (CM), and blood meal (BM) and 1 chemical fertilizer and 1 control, collectively 19 treatments, were examined under the open-field conditions. Recommen- dations of the best results obtained should be divided into groups in the following order regarding the mineral contents and also the seasons: 0.6 BM þ 7.5 FM in the spring season, and 3.5 CM in the autumn season for N, P, and K content of cabbage. For Ca and Mg, the group division should be 1.7 CM þ 0.6 BM in the spring season and 10.0 FM þ 1.2 CM in the autumn season. The optimum recommendations for the micronutrients could be 5.0 FM þ 1.0 BM in the spring season and 0.9 BM þ 0.85 CM in the autumn season for Fe and Cu and 15.0 FM in the spring season, and 10.0 FM þ 0.4 BM in the autumn season for Mn and Zn. FM and CM could be used in high rates in producing organic cabbage and could be substituted for chemical fertilizer especially in the spring season. KEYWORDS: Organic; conventional; cabbage; mineral content INTRODUCTION Care about the growing conditions of foods has often been taken into consideration by customers nowadays. This is probably because of some health problem arising from the consumption of the unhealthy foods grown under intensive farming conditions such as excessive pesticides or chemical fertilizers; therefore, growing foods organically has gained popularity around the world. Additionally, Ekelund ( 1 ) reported that more than half of the persons polled claimed to be willing to pay more for organically grown products. Moreover, environmental concerns have made a gradual steady increase because of the chemicals polluting the limited sources of the world such as water and soil. One of the most important roles of agricultural production is to provide almost all essential minerals and organic nutrients to humans ( 2 ). Organically grown crops are believed to be healthier and to contain more minerals and vitamins than that of the conventional counterparts ( 3 , 4 ). Leafy vegetables are an impor- tant source of vitamins and nutrients in the human diet ( 5 ). Of leafy vegetables, cabbages belong to the Cruciferae family and are related to turnips, cauliflowers, and brussels sprouts ( 6 ). Cabbage has been used as food for more than 3000 years and the ancient Greeks held cabbage in high esteem ( 7 ). El-Shinawy et al. ( 8 ) stated that there is a correlation between the amount of nitrogen applied and the quality of cabbage. Cabbage head could not form if there is a nitrogen shortage; phosphorus and potassium are also important for head formation and quality of cabbage. The economic importance of cabbages results from their nutritious value, high yields from a unit area, and the possibilities of differentiated utilization throughout the year ( 9 ). Cabbage is rich in nutrient and contains a range of essential vitamins and minerals as well as small amount protein and good caloric value ( 10 ); it also contains potassium, soluble and insoluble fiber, is low in sodium, and is free of fat and cholesterol. A 100 g serving of fresh green cabbage contains over three-fourths of the recommended daily allowance (RDA) for vitamin C, and also a 100 g serving of undrained sauerkraut contains 19 calories, has no fat, provides fiber, and has 25% of the RDA for vitamin C ( 11 ). Moreover, cabbage ranks higher than tomato but lower than spinach in mineral content ( 7 ). In addition, organically grown cabbage contains 43% vitamin C, 41% iron, 40% magnesium, and 22% phosphorus in higher amounts than that of the conventionally counterparts ( 12 ). Cabbages could be easily grown under a wide variety of conditions and are adaptable to many areas ( 6 ). On the basis of the Food and Agriculture Organization (FAO) data, the production area of cabbage and other brassicas occupied 3 082 058 ha (ha) and the world produc- tion was 68918 014 tons in 2007 ( 13 ). In organic farming, it is important for there to be a sufficient plant nutrient in soil, and organic manure application is sure to supply the plant nutrient to some extent depending on the material. Therefore, as stated by Abou El-Magd et al. ( 14 ) organic manure plays a direct role in plant growth as a source of all necessary macro- and micronutrients in available forms during mineralization, improving the physical and physiological proper- ties of soils. *To whom correspondence should be addressed. E-mail: ssonmez@ akdeniz.edu.tr.