Author/Authors :
EKBERLİ, İmanverdi Ondokuz Mayıs Üniversitesi - Ziraat Fakültesi - Toprak Bölümü ve Bitki Besleme Bölümü, Turkey , KARS, Nalan Ondokuz Mayıs Üniversitesi - Ziraat Fakültesi - Toprak Bölümü ve Bitki Besleme Bölümü, Turkey
Abstract :
In this study, effects of increasing dose application (0.5 ppb, 1 ppb and 2 ppb) of 2,4-D herbicide on changes in catalase enzyme activity and kinetic parameters (Vmax, Km and Vmax/Km) in a loamy soil were investigated depending on substrate concentration and incubation time. For this purpose, an experiment was conducted in a randomized plot design with three replicates and carried out at the laboratory of Soil Science Department of Agricultural Faculty at Ondokuzmayis University. During the experiment, decreased moisture level in soils was completed to 40% of maximum moisture holding capacity by weighing everyday. Catalase enzyme activity was determined in soil samples taken 15., 30., 45., 60., 75. and 90. days of the experiment, and kinetic parameters of this activity were also calculated. In increasing applications of 2,4-D herbicide, significant differences (P 0,01) were determined among the incubation periods while the effect of increasing doses on catalase enzyme activity was not significant. The highest catalase activity in 30 days of incubation was determined in control as 189.2 ml O2 gr^-1 and in 1 ppb herbicide application as 198.9 ml O2 g^-1. The highest mean Vmax value was also obtained in 1 ppb herbicide application as 0.442 ml O2 g^-1 in 30 days of incubation. While the highest mean value of Km (1.440 ml O2 sec^-1) was determined in control, the lowest value of Km (1.214 ml O2 sec^-1) was determined in 0.5 ppb herbicide application. Mean Vmax/Km values of control, 0.5; 1 and 2 ppb herbicide applications were 0.645; 0.446; 0.425 and 0.513 (sec^- 1), respectively.
NaturalLanguageKeyword :
Soil , catalase activity , herbicide , kinetic parameters.
