Determination of nutritional status in tomato (Solanum lycopersicum L.) greenhouses in manavgat region and monitoring of periodical change in soil salinity

This study aimed to examine the nutritional status of the plants cultivated in the tomato (Solanum lycopersicum L.) greenhouses on single cycle basis in Manavgat region, while monitoring the changes in soil salinity during the vegetation period. In this context, soil samples were taken from two different soil depths (0-20 cm and 20-40 cm) during four different periods (September 2014, November 2014, March 2015, June 2015), along with leaf samples taken from the same greenhouses (2014 November). The analyses conducted on the soil samples obtained were EC, pH, organic matter, CaCO3, texture, total N, available P, exchangeable K+, Ca+², Mg+2, Na+, available Fe+2, Zn+2, Mn+, Cu+2 analyses. In addition, N, P, K, Ca, Mg, Na, Fe, Mn, Zn and Cu contents of the leaf samples taken from the tomato greenhouses were also determined. The results of the texture analysis performed in the soil samples showed that the soil of the surveyed land generally had a texture of sandy clay loam, mainly slightly alkaline and alkaline properties, with no salinity problems. In general, the soils displayed a calcic structure to a degree that may cause negative consequences in terms of cultivation, while they were observed to contain insufficient content of organic matter. In terms of macronutrients, the samples showed very good total N content in general, high available P values, varying degrees of exchangeable K according to limit values, and insufficient potassium nutrition. On the other hand, the exchangeable Ca values were medium and good, exchangeable Mg content good, and exchangeable Na was low. In terms of micronutrients, available Fe and Zn contents were good, while available Mn and Cu were found to be sufficient. According to the leaf analysis results, of the leaf samples were determined in terms of the total N content was usually sufficient and high, in terms of P generally sufficient, in terms of K deficient, in terms of Ca high and sufficient, in terms of Mg sufficient, in terms of Fe deficient, in terms of Mn largely sufficient, in terms of Zn deficient and sufficient, with in terms of Cu varying between sufficient and deficient limit value. As for the changes in the soil salinity during in vegetation period, the EC values in the depths of 0-20 cm and 20-40 cm increased over time and these rises never reached critical values that may prevent plant growth. In the 0-20 cm soil depth, the EC value was minimum 0.30 dS m-1, maximum 2.04 dS m-1, while in the 20-40 cm soil depth it was determined to be minimum 0.35 dS m-1, maximum 3.29 dS m-1. Especially, the low levels of salinity in the effective plant root depth found to be significant in terms of any decrease of losses that may occur in the yield. In conclusion, the soils from the greenhouses were determined to have high pH and high lime content, and it is considered that this condition might lead to certain problems in plant nutrition. Besides, the organic matter content of the soils was insufficient. Determined to be commonly deficient, the elements of K, Fe, Zn and Cu should be given special attention in plant nutrition in view of their vital significance in cultivation. Taking necessary measures to balance the high pH and lime values in the growing environment is important to increase the yield. KEYWORDS: Manavgat, tomatoes, nutritional status, soil salinity