Effect of Planting Hole of Film Mulch and Imitation Canopy on Soil Temperature

Abstract

The purpose of this paper is to clarify the effect of the planting hole diameter of film mulch on soil temperature in relation to canopy quantity. The experiment was conducted from September 2006 to January 2007. Imitation canopies were used instead of real plant. All experimental plots had the same of plant coverage, but different leaf area indexes (LAI). In no plant plots, temperature was lower when the planting hole diameter was larger. In plant plots, however, the difference was not significant, and ratio of daily range of soil temperature decreased as plant increased. Among plots with an LAI of 0.6 or larger, the plot with 10 cm diameter holes showed the smallest ratio of daily range of soil temperature. As for the distribution of soil temperature differences between plots with different size planting holes and Mn plots, the average, highest frequency, and kurtosis all tended to be smaller when the planting hole diameter was larger.