Ali Rıza Ongun

Effects of Tobacco Waste and Farmyard Manure on Soil Properties and Yield of Lettuce (Lactuca sativa L. var. capitata)

The aim of this study is to compare the effects of composted tobacco waste (CTW) with farmyard manure (FYM) on soil physical and chemical properties and yield of lettuce. This research was performed in the experimental fields of the Agriculture Facultys research farm at Ege University in Menemen, Izmir, Turkey in 2005 and 2006. Tobacco wastes gathered from the cigarette industry were composted and applied to lettuce (Lactuca sativa L. var. capitata) with manure. Mineral fertilizers or pesticides were not applied in the experiment. The treatments were (1) control, (2) 12.5 t ha–1 FYM + 37.5 t ha–1 CTW, (3) 25 t ha–1 FYM + 25 t ha–1 CTW, (4) 50 t ha–1 FYM, (5) 50 t ha–1 CTW, and (6) 37.5 t ha–1 FYM + 12.5 t ha–1 CTW. During the experiment, soil samples were taken three times in two different periods (I, 7 September 2005; II, 11 November 2005; and III, 14 April 2006). The effects of CTW and FYM on soil physical and chemical properties and the yield were investigated. All application rates increased bulk density, field capacity, available water content, and structure stability index of soil when compared with the control. In addition, similar effects were also determined for chemical properties of soil (pH, lime content, organic matter, total soluble salt, and cation exchange capacity). Increasing rates of nitrogen, phosphorus, and potassium provided a rise in the yield. Maximum lettuce yield was 102.7 t ha–1 at the plots where 50 t ha–1 CTW was applied. The results show that CTW can be used as an effective soil conditioner.