Effects of biochar and fertilizer application on soil properties and nutrient status of lettuce

Filiz Öktüren Asri1*
Different ways of benefiting from plant wastes in agricultural production are developed. One of the methods is to convert wastes into biochar and use it as a soil regulator. This study was conducted to determine the effects of biochar produced from tomato (Solanum lycopersicum L.) plant waste on soil fertility and nutritional status of the lettuce (Lactuca sativa L.) plant. For this purpose, the combined effect of five different doses of biochar (0, 10, 20, 30, and 40 t ha-1) and three chemical fertilizers (control, half-dose NPK and full-dose NPK) were investigated. The research was conducted in two cultivation periods. Biochar was applied to the soil just in the first period. In the first period, applications increased electrical conductivity, organic matter content, total N, and concentration of available P, Zn, and Mn, and the exchangeable K and Mg in the soil. Biochar and chemical fertilizer applications positively affected the lettuce plant’s N, P, and K concentrations. In the second period, concentrations of the available P, Fe, Zn, Mn, Cu and exchangeable Ca, Mg in soil, as well as the N, P, Ca, Mg, Zn, and Cu concentrations of the plant are higher compared to the first period. It was determined that biochar application alone was not sufficient for the nutrition of the lettuce plant, chemical fertilizers should be used additionally. In lettuce cultivation, half-dose NPK was recommended in addition to 30 t ha-1 biochar. As a result, it was determined that biochar produced from tomato plant waste was an effective soil improver material and might be an alternative source of K.
Keywords: Biochar, Lactuca sativa, nutrient availability, organic matter, potassium, tomato plant waste.
1Bati Akdeniz Agricultural Research Institute, Soil and Water Resource Department, Antalya, Turkey Demircikara Neighborhood, Pasa Kavaklari Street PO Box: 35 Muratpasa/Antalya-Turkey.*Corresponding author (filizokturen@gmail.com).