EFFECT OF SOIL PREPARATION METHOD ON SOIL TEMPERATURE
The success of the forest regeneration with planting is determined by many factors and one of them is soil preparation. Chosen soil preparation method impacts different environmental aspects and one of them is soil temperature and that is one of main abiotic factors determining the growth of roots. Development of the root system is a key prerequisite for growth of newly planted trees. The aim of this research was to assess the impact of the soil preparation method on the surface (5 and 20 cm) temperature of the soil. The study was done in 8 young stand sites with different soil preparation methods, soil preparation design (orientation relative to cardinal points) and different forest types in central and north-western part of Latvia. Soil temperature measurements were taken at 5 cm and 20 cm depths in both sides of furrows and in spot mounds at every study site with hand held thermometer, in few young stands unprepared soil temperature was also measured. Mean values and standard error were calculated and the statistical significance was determined by: the Shapiro-Wilk normality test, the Kruskal-Wallis Test and pairwise Wilcoxon test with a 95% confidence level. Our results show that soil preparation positively impact soil temperature compared to unprepared soil and soil temperature in spot mounds was significantly higher than in furrows during clear and hot (27-32°C) day at both depth and in overcast weather with moderate air temperature (20-23°C) in depth of 20 cm.